[Amps] Alpha 87A fault 33 when pressing TUNE DOWN
Dave
rocketnj at gmail.com
Sun Aug 4 14:12:04 EDT 2019
Thanks Larry. I’ll check into it. Also not sure if the Alpha 87A Yahoo group still exists.
Good news is fault 8 is fixed with PIN diode change (rx and tx). But now fault 33. My friend bought this at a hamfest where the seller claimed it was from an estate and it was “tested fine”. When I opened it up one TX pin diode had one side cut right at the diode. It tested bad. 2 receive pin diodes tested bad as well. Now -109 vdc is happy again.
Dave wo2x
73
Dave wo2x
Sent from my iPad
> On Aug 4, 2019, at 1:56 PM, Larry Dighera <Larry at kj6yvt.com> wrote:
>
>
> Hello again Dave,
>
> Several years ago I archived some of the Alpha 87A support messages
> posted to the RF Concepts web site. (See below.) Unfortunately, I
> don't find a support message that specifically addresses Fault 33.
>
> This page
> <https://web.archive.org/web/20120211083035/http://asktheham.com/node/8>
> on archive.org contains some of the messages, but is incomplete,
> unfortunately. However, as you are doubtless aware, this page
> <https://www.alpharfsystems.com/?p=1560> appears to have the old
> content.
>
> I've added Glenn W Pladsen (AE0Q) as a BCC on this message. Glenn is
> very knowledgeable about the Alpha 87A, as he has serviced them
> professionally for many years while employed by RF Concepts and their
> successors. I have found Glenn's sharp insight and decades of
> experience with ETO products very helpful on several occasions, and
> his gracious spirit of cordial assistance is very much appreciated.
> Hopefully, Glenn will assist you.
>
> Best regards,
> Larry
> WB6BBB
>
>
> -----------------------------------------------------------------------
> https://web.archive.org/web/*/http://asktheham.com/forum/*
>
>
> To: Alpha87a at yahoogroups.com
> Subject: Re: [Alpha87a] Explosive Arcing
> From: "Glenn Pladsen gm5bkc at gmail.com [Alpha87a]"
> <Alpha87a at yahoogroups.com>
> Date: Tue, 19 Aug 2014 23:47:21 -0500
> Hello Larry,
> The 87A switches the HV from low setting (about 1600vdc) to high
> (about
> 2700v) at the end of the warmup period if the HV switch is set to HI,
> which
> is where it should always be. So the arc is occurring just as the HV
> goes
> high.
>
> I would suggest doing as you said, removing the cover and blowing it
> out, and pay particular attention to the small RF choke and yellow (or
> orange) HV bypass capacitors that are in the HV path on the RF side of
> the center partition. The RF choke is just below the solenoid that
> shorts out the top of the vertical plate choke, The RF choke is about
> an inch long and positioned horizontally, one end may be too close to
> the center chassis.
> Glenn AE0Q
> RF Concepts
>
> On Tue, Aug 19, 2014 at 7:07 PM, Larry Dighera larry at kj6yvt.com
> [Alpha87a] <
> Alpha87a at yahoogroups.com> wrote:
>>
>> Hello Alpha operators and technicians,
>>
>> Shortly after I purchased my 87A a couple of years ago, a very loud arc
>> occurred just as the warm-up period expired. I feared the worst, but since
>> then it has functioned fine enabling me to work stations all over the
>> world.
>>
>> A few weeks ago I switched on the 87A in the hope of contacting a weak
>> station.
>> Waiting through the three minute warm-period was abruptly punctuated with a
>> very loud report, and the 87A and DAS shutdown (without fault code
>> indication, of course). I figured all was lost.
>>
>> Later, I again toggled the POWER ON rocker just to see what would happen.
>> To my amazement, all functioned nominally with no need to reset anything. A
>> look at the hard and soft faults showed the most recent soft fault to be 17 and
>> the hard fault 24. Hmmm... I'm a bit doubtful that the 87A had time to record a
>> fault, but something did what appears to have been an orderly shutdown
>> without blowing a fuse of emitting smoke.
>>
>> Yesterday the arc occurred again. Because the 87A had operated okay after
>> the earlier arc, I thought that it may have been caused by some internal dust
>> accumulation or insect shorting the works as a result of month's period of
>> non-operation, and I hoped the resulting arc may have blown the dust out.
>> But obviously I was wrong about that. These arcs all occurred spontaneously at
>> the end of the warm-up period without any exciter input.
>>
>> So, now I'm planning on opening the 87A, and visually searching for any arc
>> indications as a clue to the cause. I'm thinking that a good blow-out with
>> compressed air may be helpful.
>>
>> <snip>
>>
> Best regards,
>> Larry
>>
> --------------------------------------------------------------------------------------------
> http://asktheham.com/node/289
> Fault 1 revisited plus some other maintenance.
> published by wo2x on Sun, 06/26/2011 - 19:05
> Forums:
> Alpha 87A Entries
> Hi All,
> Thought I would share my recent troubleshooting of an Alpha 87A amp.
> Got my friend's 1991 ETO 87A for repair for fault 1 error (soft
> fault).
> The amp has had the pin diode upgrade and resistor/diode string mods
> done at the factory several years ago. Also the choke and spark gap on
> the T/R board.
> I was following the fault 1 troubleshooting procedure and found it is
> not 100% correct.
> After following step 3 the amp was not faulting with F2 on the output
> T/R board removed. THis shows it is probably D2 and D8. This was not
> the case. D2 and D8 tested fine with the Fluke 77 (1.5 M Ohms). I
> replaced them as a precaution anyway. Still fault 1 with F2 in and no
> fault with F2 out.
> Further troubleshooting found R5 on the output T/R board open (10 M
> Ohm, 1/4 watt). I also tested D6 and D11 (which had 3.3 M Ohm
> resistors paralled to them) and found the diodes a little leaky. I
> replaced R5 , D6 and D11. No more fault 1 and back on the air!
> While I had it on the workbench I added another 200 volt zener to the
> diode string on the HV board to raise the bias voltage up to 900 volts
> instead of 700 (later 87A's have this extra diode). Also, the amp had
> intermittent fault 37 condition (bandswitch not moving. I found the
> gear from the stepper motor to bandswitch shaft tight and binding. I
> loosened the screw on the bottom of the amp and retightened after
> fixing the binding. This could have been from the amp being picked up
> by the corners instead of by the sides and torquing the chassis.
> Another precautionary measure I did was clean the pins on the Molex
> connectors which can lead to intermittent fault 24 problems.
> Amp in back on the air and working great!
> 73
> Dave wo2x
> ======================================
> http://asktheham.com/node/220
> Here is the list of upgrades possible
> published by administrator on Fri, 01/28/2011 - 13:51
> Forums:
> Alpha 87A Entries
> Hello Paul,
> Here is the list of upgrades possible. If your amp was here we would
> add a 1N5383 150v Zener diode to raise the RCV PIN diode bias voltage
> to 900vdc (yours probably has 4 Zener diodes mounted above the HV
> bleeder resistors, and is about 750vdc).
> 73 - Glenn AE0Q
> --------------------------------------------------
> 87A UPGRADE
> Note: all directions, i.e. front, rear, left, right - assume
> positioning amp with front panel facing reader HIGH VOLTAGE POWER
> SUPPLY - Verify that there are (5) (R40-R44) 220k 2-watt resistors on
> a level above the rest of the devices on the board. The ground end of
> this string should consist of zener diodes that are heat-shrink
> covered. If this construct is present, remove D15 from the board. It
> is redundant and can cause a fault 1 if it leaks. If this construct is
> not present this board needs further revision and D15 should not be
> removed. Another hint that R40-R44 are present is that R27 should
> already be missing. If R27 is not missing, don't remove D15.
> Remove 4 H.V. diodes, D1 through D4, and replace with DRX-X136
> (mono-block). See attached instructions. Double stick tape is already
> on the bottom of device. Clean board and mount diode where D1 and D3
> were.
> EPROM - Microprocessor board UPX-X108-G, U7 - Unplug the amp -
> processor is live when amp is plugged in, and the cover-microswitch
> is made, whether the amp is turned on or not turned on; even when the
> transformer is removed from the chassis.
> Front Panel has 2 screws per side and 5 along the bottom front edge of
> chassis. 2 cables between the Switch Board and the Motor Driver Board
> will have to be detached at one end or the other (note Pin 1 so you
> can put the connector back correctly). The 4-pin berg connector to
> Display board may also have to be removed depending on the cable
> routing. Now you should be clear to lay the front panel down towards
> you on its face. The processor board will be facing you on the right
> side of the inner front wall of the main chassis. Carefully remove U7
> (bottom right quadrant of board, near square processor) and install
> 108-G (pin 1 left top). Ensure all pins slide into socket. Re-install
> cable connectors and front panel.
> OUTPUT T/R MODULE - Remove the two screws on the front and left side
> edge of the perforated cover (rear-center) to give you access to the
> Output T/R board (the horizontal board under the cover). Blue 10meg
> resistor is on the Output T/R, reference designator R5. If it's
> already a ½ watt (probably black or physically bigger) (as opposed to
> ¼ watt, standard color code stripes) and you're not getting fault 1,
> you can leave it alone. (You can't successfully measure it to verify
> value in circuit. If it's open, parallel resistances will mask it.)
> The safety choke installation requires a hole in the Output T/R module
> sub chassis. The hole should be 5/32", 5/8" from top of front vertical
> wall of sub-chassis, and 1 and 3/8" in from left corner of
> sub-chassis. The washer and nut to attach the choke to the sub-
> chassis should be on the part already, "behind" the thread protector
> porcelain. The porcelain can be discarded. The safety choke is
> positioned inside the Output T/R module running north-south (thread
> end towards you, through the hole you just punched). The foam strip
> (XKX-X118) goes on top of the choke, between the choke and the output
> T/R cover. The lead on the opposite end from the threads of the device
> should have a Teflon sleeve and needs to be soldered to the RF output
> (heavy gauge wire from output T/R board to RF output connector). The
> spark gap arrestor runs from this same point (RF output) to chassis
> ground. Attach right angle solder lug HLX-X130 to Output Wattmeter
> board (Vertical on rear wall of Output T/R sub- chassis) with flat
> head screw HSS-3018. Mounting point is output connector top-right
> corner. Connector is threaded. This is the chassis ground end for the
> Spark gap arrestor. Solder one end of the arrestor to the lug you just
> attached to the Output Wattmeter board/RF output connector. Again, the
> other end should be soldered to the RF Output itself. Ensure that
> positioning of this device does not cause it to come into contact with
> the Output T/R subchassis' perforated cover. Ensure that the solder
> lug does not touch the Output toroid.
> LOW VOLTAGE POWER SUPPLY - The 100uF 25V "Fault 24 mod" cap goes on
> the LVPS, which is the vertically mounted board below the horizontal
> HVPS. Solder the negative lead of the cap to pin 12 of U4. U4 is the
> only 14 pin IC on the LVPS. Solder the positive leg of the cap to pin
> 1 of U4. Tip the amp (after you've removed the transformer) towards
> you on its face very gently. Put a cloth or something down so you
> don't scratch panel. If you lean your head over the amp the LVPS will
> now be horizontal and facing you. In addition to being the only 14 pin
> IC, U4 is the closest IC to the HVPS. Bend the leads of the cap at a
> right angle down, while holding the cap horizontal with the negative
> lead towards you. Bend the negative lead just past the body of the
> cap. Stagger the positive lead length between the body and the bend an
> additional ¼" (two IC pins). Trim the lead length of the cap so that
> the cap sits horizontally on the IC. Sooner or later your ability to
> follow instructions and craftsmanship will be judged.
> PARTS LIST
> CEX-1077 100uF, 25 V cap (LVPS board)
> DRX-X136 HV mono-block diode bridge (HVPS board)
> RFM-D106A 10 megohm, ½ watt resistor (OUTPUT T/R board)
> LCX-X105 Safety choke (OUTPUT - output t/r module)
> CGX-8010-D Spark gap Arrestor (OUTPUT - output t/r module)
> UPX-X108-G EPROM, last version before AlphaMax version 1.00AT
> (Microprocessor board)
> ====================================================================
> http://asktheham.com/node/101
> What is the best way to use the 87A AlphaMax functions?
> published by administrator on Sat, 12/04/2010 - 22:33
> Forums:
> Alpha 87A Entries
> What is the best way to use the 87A AlphaMax functions?
> When the new (since 1999) AlphaMax (Autotune) firmware is installed in
> the 87A, the TUNE and LOAD LEDs will blink to indicate what the
> AlphaMax program would do if it was enabled.
> An addendum to the 87A manual was included with AlphaMax kits thatwere
> installed in the field, or you can download a copy of the new version
> of the 87A manual (with instructions for using AlphaMax) from our web
> site: here
> You should tune up the amp with your antennas on each band/segment
> andsave the settings in USER memories. When changing bands the 87A
> first goes to the USER memory setting. If further tuning is needed it
> willmake the adjustments if the Autotune mode (AlphaMax) is enabled.
> If it is not enabled, the TUNE and/or LOAD LEDs will blink to
> indicatewhat direction those would be moved.
> If it is not in Autotune and the user settings are not at all close to
> desirable, it will fall back to factory-saved default settings (for a
> 50 ohm load) and the DEFAULT LED will light solid. If that is not
> close enough to get normal output with the current load, the amp will
> get a Fault 17.
> The Autotune function is enabled by pressing the LOAD^ and ENTER
> buttons at the same time. The DEFAULT LED will flash when Autotune is
> enabled and the amp is in operate and warmed up.
> Please note that the TUNE meter is a rough indicator to allow the amp
> to be tuned with low drive levels so that it is close to being set for
> 1500w output. Once you increase the drive and are close to 1500w out,
> fine tune by adjusting the TUNE and LOAD controls for maximum output
> at the drive level you are at. This should correspond to a dip in the
> plate current. The TUNE LED may be a number of LEDs off center to
> either side. The most useful multimeter parameter to monitor when
> transmitting is the Ip (plate current), also watching the Ig (grid
> current).
> The TUNE meter is calibrated on 20m when the amp is tuned up for 1500w
> out, with new tubes. As the tubes age, it will indicate off center a
> bit. Line voltage that is not at the nominal value for each range
> (200, 220 or 240v) may also affect the TUNE calibration.
> Since the 87A has memories that should be saved for the tuneup
> settings for each band segment, the TUNE meter isn't really as useful
> as it is with a manually tuned amp (Alpha 89/91B/99)
> ================================================================
> To: Alpha87a at yahoogroups.com, Barry J Cohen <n2bj at comcast.net>
> Subject: Re: [Alpha87a] ALPHA 87A Code 9 faults
> From: "GWP gm5bkc at gmail.com [Alpha87a]" <Alpha87a at yahoogroups.com>
> Date: Sun, 23 Oct 2016 10:04:47 -0600
> Here are the Fault 9 troubleshooting notes.
> Glenn AE0Q.
> =============================
> Fault 9 is a problem with the -109vdc PIN diode bias voltage,
> usually
> caused by the PIN diodes or sometimes the power supply.
>
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function. You do NOT need to remove the diode from the
> chassis of the amplifier, just unsolder one of the flat, metal leads
> of the diode.
>
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another meter
> here that uses only 0.25vdc in the resistance function, and it reads a
> good diode ever higher (about 1.5 megohm) in forward bias, and
> 3.9 megohm in reverse bias.. Measure your meter in the normal
> resistance check function with another in the volts range to check
> the bias voltage that is used (leads connected together).
>
> The tan/yellow diodes in the T/R module are KS1001 types (the
> Recieve PIN diodes), and with one end lifted and 0.75vdc from the
> meter used to FORWARD bias it, they read 1.5 megohm. The
> REVERSE bias reading must be close to 3.9 megohm. If yours
> are reading 10k and your meter uses a similar voltage on the test
> leads, then it is leaking too much and the diode is bad.
> With the POWER OFF, remove the amplifier cover and measure the
> resistance from chassis to the tank coil, there should NOT be a short.
> If there is, that will cause a Fault 9 because the -109 goes through
> the
> two resistors mounted on the left side of the chassis. Check the
> small
> blue capacitor from bandswitch to the chassis located near the little
> circuit board on the chassis, left side. This should NOT be shorted,
> it
> should be a high resistance. If it is close to zero ohms, then there
> is
> something shorting to ground in the RF section of the amplifier. Also
> Check diode D1 (1N5404) on the Safety Choke Board, mounted on the
> chassis near the two resistors. Check ALL connections on the
> Safety Choke board.
>
> Defeat BOTH interlocks. Put the plastic cap of a Bic pen on the
> screw
> of the HV shorting spring to insulate it.
>
> Connect the 87A to AC power and turn it on. Be VERY CAREFUL, there
> is
> 3000v in the power supply and on the tubes!
>
> 1) Measure the -109vdc at either end of the large resistor mounted on
> The chassis at the left side of the RF section. If it is below 89
> volts
> when receiving, that is causing the fault, check PIN diodes. First
> remove the end of the coax cable on the little circuit board (Safety
> Choke
> Board), turn on the amp and measure -109 again. If normal (above
> -89vdc)
> there is a bad Power PIN diode (on the ABX-X220 board in the T/R
> Module).
> Reconnect coax center to Safety Choke Board.
>
> 2) Pull connector J12 (5 pin connector) at edge of Low Voltage Power
> Supply and measure for -109 on J5-2,3, if OK put back on. This
> can be difficult to do with transformer installed in amp, as an option
> go to step 3.
>
> 3) Pull connector J1 on Input T/R board (under tube deck), measure
> -109v
> there (P1-3, measure on cable connector not circuit board). If bad,
> problem is usually in LVPS. Plug in connector and measure again, if
> voltage is good at J1 but bad at Safety Choke Board, it may be a
> shorted
> Q2 (Input T/R Board). Go to step (4) before changing Q2, it is turned
> on/off by the +/-30v.
>
> 4) Measure +/- 30v on connector in T/R module, J2-2,3. It should be
> +30v when NOT keyed, and -30v when keyed.
>
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function.
>
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another meter
> here that uses only 0.25vdc in the resistance function, and it reads a
> good diode ever higher (about 1.5 megohm) in forward bias, and
> 3.9 megohm in reverse bias. Measure your meter in the normal
> resistance check function with another in the volts range to check
> the bias voltage that is used (leads connected together).
>
> The tan/yellow diodes in the T/R module are KS1001 types (the
> Recieve PIN diodes), and with one end lifted and 0.75vdc from the
> meter used to FORWARD bias it, they read 1.5 megohm. The
> REVERSE bias reading must be close to 3.9 megohm. If yours
> are reading 10k and your meter uses a similar voltage on the test
> leads, then it is leaking too much and the diode is bad.
>
> There is also a KS1001 PIN diode under the tube deck that should be
> checked if the other 4 are OK.
>
> Check L1 (in the T/R Module) for any traces of an arc or burn. It
> may be under L1 (use some epoxy material for isolation).
>
>
> On Sun, Oct 23, 2016 at 7:37 AM, n2bj at comcast.net [Alpha87a] <
> Alpha87a at yahoogroups.com> wrote:
>
>>
>> I could use some input. I was on 75M a few weeks back in one of the RTTY
>> contests and all of a sudden I started getting CODE 9 Faults
>>
>> 2 weeks of troubleshooting by one of the best in the field has found that:
>>
>> "Still getting a fault. Using a 100: 1 probe I connected my oscilloscope
>> to RBIAS. It's 750 volts and should be 0 volts during receive. There's no
>> "R"
>>
>> 5 volts coming from the micro. "
>>
>> Anyone have any input that could help us out??
>>
>> Thanks
>>
>> 73
>>
>> Barry
>>
>>
>> my direct email is:
>> n2bj at comcast.net
>>
> Glenn, Merri, Hildie IJC, WV-I
> and NATCH Katie,
> NADAC Elite Versatility Award, O-TG-E, HP-O,
> MXB, MJB, OF,
> APD, APG, APR, APK,
> SPG, SPR, SPK, SPJ
> S-SSA, S-SSLA, S-STA, S-SJA, S-IAA,
> http://www.hoopsandjumps.com/
> http://funagility.webs.com/
> --------------------------------------------------------------------------
> http://asktheham.com/node/64
> Alpha 87A Checking PIN Diodes
> published by administrator on Sat, 12/04/2010 - 21:09
> Forums:
> Alpha 87A Entries
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function.
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another
> meter here that uses only 0.25vdc in the resistance function, and it
> reads a good diode ever higher (about 1.5 megohm) in forward bias.
> Measure your meter in the normal resistance check function with
> another in the volts range to check the bias voltage that is used
> (leads connected together).
> The tan/yellow diodes are KS1001 types, and with one end lifted and
> .75vdc from the meter used to forward bias it, they read 1.5 megohm.
> If yours are reading 10k and your meter uses a similar voltage on the
> test leads, then it is leaking too much.
> Log in or register to post comments
> K4VUD
> Sat, 01/29/2011 - 01:44
> Permalink
> Fault 9 and PIN diodes
> I have had Fault 9 on TWO different 87a amps over the past 20 years.
> One went back to factory THREE TIMES and the other Twice. The problem
> happened again after the "fix" and the one I have now is stuck again
> on Fault 9.
> This seems to be a design flaw in this amp and the only fix appears to
> replace the failed parts at the factory price of about $350, plus
> shipping. There is a factory add-on that promises to retard RF from
> another big amp operating near the 87a from coming into the 87a and
> blowing some of these parts that give Fault 9, but I put all that
> stuff in and still have Fault 9 right now.
> I think I will just sell this un-fixable thing and get something
> better.
> =========================================================
> http://asktheham.com/node/62
> Alpha 87A/89 Amplifiers and AM
> published by administrator on Sat, 12/04/2010 - 21:09
> Forums:
> Alpha 87A Entries
> To run AM with an amplifier, you should tune it up first at the full
> power level of the AM signal that is 100% modulated. If this is going
> to be 1500w, the carrier power with NO modulation would then be set to
> 375w without retuning the amp (set it with the drive control on the
> transceiver in AM mode).
> The ALPHA 87A uses a pair of Eimac 3CX800A7 tubes, grid driven in
> Class AB2.
> Carrier-only output is limited by the facts that
> (1) the amplifier must remain linear on 100% modulation peaks, which
> are 4x the carrier power,
>
> (2) efficiency of an AB or B linear amplifier at 25% of design power
> output (or more to the point, at 25% of the peak output power for
> which it's tuned up) is typically about 30% ... it pretty much runs
> Class A at that power level, and (3) consequently, power supply
> loading and tube plate dissipation are the limiting factors under
> carrier conditions (without modulation).
> Let's assume linear operation with 100% A3 amplitude modulation,
> yielding the 87A's nominal rated PEP output of 1.5 kW. By definition,
> carrier output must be 375 watts. Assuming ~30% plate efficiency under
> carrier-only conditions, d-c plate input must be in the vicinity of
> 375/0.3 = 1250 watts. Most of the difference, or 1250-375 = 875W, is
> plate dissipation.
> As it happens, the 87A can comfortably handle both of these
> parameters, although one definitely should use a good, high-output
> "Muffin" type auxiliary cooling fan to keep the tubes and cabinet cool
> under continuous duty conditions.
> ============================================
> http://asktheham.com/node/61
> Alpha 87A Wattmeter Scaling
> published by administrator on Sat, 12/04/2010 - 21:08
> Forums:
> Alpha 87A Entries
> 1) Connect PC to serial port with a modem program communicating with
> the amplifier.
> 2) With the 87A in STANDBY, transmit through the amplifier with 100 w
> steady carrier (use CW or RTTY) from the radio to a dummy load or
> antenna with low SWR.
>
> 3) On the PC, type EXT ON.
> 4) On the PC, type GPIO (radio still transmitting 100w). This command
> reports Grid current, Plate current, Input power, and Output power
> each time it is typed. It should be showing about 100w input and
> output. If one of those is not reading correctly, either the wattmeter
> diodes are damaged or it just needs to be rescaled.
> Rescaling the wattmeter calibration involves changing data in the
> microprocessor tables. This involves reading and changing data at
> certain memory locations, the data is in hexadecimal format (base 16).
> Instructions are below.
> The Input Power scaling factor is stored in addresses B79B and B79C.
> The Output Power scaling factor is stored in addresses B79D and B79E.
> 1) Read the hex values stored in those locations (write them down!!!):
> type
> EXT ON(ENTER)
> DM B79B(ENTER) (record the first 4 pairs of hex numbers, left to
> right)
> The data in B79B is the first pair, the data in B79C is the 2nd pair,
> data in B79D is 3rd pair, and data in B79E is 4th pair of hex numbers.
> 2) To raise the INput power reading, increase the number in B79C
> (lower the number to lower power reading):
> W B79C xx(ENTER) xx = original hex number plus 16 (for example, 8E
> changes to 9E, 9E would be changed to AE, etc) Finer increments result
> from changing the last digit, for more coarse increments you could
> change the last digit in B79B by one. Change scaling up or down as
> needed.
> After every change, transmit 100w through amp (in standby) and type
> GPIO command to read wattmeters.
> 3) To raise the OUTput power reading, increase the number in B79E.
> W B79E xx(ENTER) xx = original hex number plus 16
> ====================================================
> http://asktheham.com/node/60
> Alpha 87A noise on receive
> published by administrator on Sat, 12/04/2010 - 21:08
> Forums:
> Alpha 87A Entries
> When this occurs move the tune cap out of resonance in RX and the amp
> in operate and no drive. If the noise changes it is the TX diodes. If
> it does not it is the RX diodes.
> ===============================
> http://asktheham.com/node/59
> Alpha 87A HI/LO switch
> published by administrator on Sat, 12/04/2010 - 21:07
> Forums:
> Alpha 87A Entries
> You should always use the HI setting of the HV switch. The low HV is
> for some overseas customers that only have an 800-1000w output limit
> (Japan and some Europeans). The lower plate voltage forces the plate
> current to be higher, which limits their maximum output. In some
> countries they are required to show this in operation to the licensing
> authorities, etc. Control the output power by lowering the drive to
> the amplifier.
> ==============================
> http://asktheham.com/node/58
> Alpha 87A Frequency Detect Adjustment
> published by administrator on Sat, 12/04/2010 - 21:07
> Forums:
> Alpha 87A Entries
> Alpha 87A Frequency Detect Adjustment:
> The pot in the bottom of the 87A is to be adjusted as follows.
> 1. Place the 87A on it's right side.
> 2. Remove the bottom cover under the tubes.
> 3. Place the transceiver on 28mhz and adjust the power output to 5
> watts.
> 4. Place the amplifier in the 160 meters position.
> 5. Put the pot in the full clockwise position to start.
> 6. Key the radio and adjust the pot counter clockwise until the
> amplifier changes bands then stop there.
> 7. Replace the covers and place the amp back flat on the table.
>
> If the amp is still having problems changing frequency than the amp
> needs to be repaired. The problem is most likely on the frequency
> counter PCB and will need additional trouble shooting.
> =====================
> http://asktheham.com/node/57
> Alpha 87A Intermittent Frequency Detect
> published by administrator on Sat, 12/04/2010 - 21:06
> Forums:
> Alpha 87A Entries
> Intermittent Frequency Detect in Alpha 87A
> 1) Unplug amplifier from the 220vac and take apart the plug. Make sure
> the screws holding the wires are tight, they sometimes get loose. When
> you unplug the amplifier from the power, you are also resetting the
> microprocessor. It has 5v whenever the amp is plugged in, even when it
> is turned off. Resetting the microprocessor might fix it. Plug in the
> amp and turn it on. Test to see if it now works OK.
> 2) If it is still not working correctly, you will need to unplug it
> from the power again. If you have bolted the big power transformer
> into the chassis, tip the amplfier up so that it is standing on it's
> right-hand side. If the transformer is not bolted to the chassis, you
> will need to take off the cover and remove the transformer before
> setting the amp on it's right side, or put in the bolts to hold in the
> transformer now.
> 3) Remove the plate on the bottom of the chassis that is under the
> tube deck (where the tubes plug in). When you look into the opening,
> there is a white 8-pin connector in the upper right-hand corner near
> the edge of the opening. This connector carries the frequency signal
> to the microprocessor. Pull the connector off and push it back on,
> making sure that it is on all the way. In the upper left-hand corner
> there is a short jumper between two circuit boards. It should go into
> holes in the two boards that are
> labeled RF FWD. Check very closely and make sure that it is in the
> correct holes. There is one hole labeled GND and the wire should NOT
> be in this hole. Near the middle of the top circuit board, to the left
> of the white 8-pin connector, there is a small variable resistor
> (potentiometer). This adjusts the sensitivity of the frequency
> measuring circuit. The slot in the potentiometer should be about in
> the middle, pointing almost straight up. Note the position of the
> slot, then use a small screwdriver to turn the adjustment from one end
> to the other a few times. The potentiometer may have dirty contacts
> and this will clean them. Set the adjustment back where it was when
> you started. Replace the metal plate and put the amplifier back to
> it's normal position on the table.
> 4) There is one more cable that you can try to reseat. It is the other
> end of the frequency signal to the microprocessor. With the top cover
> removed, it is a long red connector that you can see at the top
> right-hand part of the amp just behind the front panel (there are two
> long red connectors together). This plugs into the control board that
> has the microprocessor. Carefully pull the connector off and plug it
> back on, making sure that it is pushed on all the way.
> Replace the top cover and test the amplifier again.
> =======================
> http://asktheham.com/node/56
> Alpha 87A Fault 99
> published by administrator on Sat, 12/04/2010 - 21:06
> Forums:
> Alpha 87A Entries
> Please unplug the 87A for 2 minutes and then plug it back in to the
> 240v. This will reset the microprocessor and can sometimes correct
> erratic operation (possibly caused by stray RF), although it will NOT
> clear hard faults or remove them from the fault log.
>
> The 87A should 'talk' to the PC anytime it is plugged into mains
> power, even when it is turned off. This is the best troubleshooting
> tool that we have.
> Below are some notes about the 87A fault protection and instructions
> for clearing the fault log.
> IMPORTANT !!!!!
> Please remember that when the 87A gets a hard fault and then the power
> is turned back on, it will report the fault for 30 seconds and then
> clear automatically. You must not turn off the power before the fault
> clears (about 30 seconds), or it will log another hard fault the next
> time the power is turned on. Also remember that six of the SAME hard
> fault shutdowns over ANY period of time (with no other kind of Hard
> fault) will then put the 87A in Fault 99 which locks it up. This
> function was put in the amplifier to prevent any further damage if
> operation was attempted after a failure had occurred. If you keep
> turning off the power before a hard fault has cleared, and this causes
> 6 of the same hard faults to be entered in the fault log, the 87A will
> then go into Fault 99 and will not turn on. Also, if the 87A is turned
> on 6 times when it keeps shutting down immediately because of a hard
> fault, it will go into Fault 99.
> Here are two sets of instructions, one for setting up HyperTerm that
> is built into most versions of Windows for the communications, and the
> second set is for clearing the Fault 99.
> To find out what the status of the amplifier is, you need to use a
> modem communications program. Windows 95/98 comes with one called
> HyperTerminal. It is usually located in the ACCESSORIES program group.
> On Win98 it may not have been installed as the default and you can
> install it by inserting the Win98 CD and selecting it in the "Add
> Programs, Communications" menu.
> When you click on HyperTerminal from the START, PROGRAMS, ACCESSORIES
> menu it will open a program group on the screen.
> Click on HYPERTRM.EXE and it will open a window for a new connection.
> Give it a name, and in the next window select the "Connect Using:
> Direct to COMx" pulldown menu (in the bottom of the box on my version
> of Win95); select the Com port you will use. If the COM port you
> select is available it will open another box called "COMx Properties".
> Going down the list, select Bps-4800, Data
> bits-8, Parity-NONE, Stop bits-1, Flow control-NONE. Click OK to close
> the window. Now pull down the FILE menu and click PROPERTIES. Click
> the SETTING tab and then click ASCII SETUP at the bottom of the
> window. Click the box for "Echo typed characters locally" (it could
> have a check in the box). Click OK to close both windows.
> Plug in the amp (power off) and it should be communicating with the
> computer. Type VER and press the Enter key. The 87A should respond
> with the firmware version number.
> ATTENTION ATTENTION !!!!!!!!!!!!!!
> If you see garble (or nothing) you will need to remove pin 22 of the
> 25-pin end of the cable (the 87A end). It is used to set the baudrate
> of the amplifier. Page 19 of the 87A manual has a complete explanation
> of the communications connections.
> When it is communicating OK, type SF and HF to display the Soft Fault
> and Hard Fault logs (press Enter key after each command). Save the
> result of those commands.
> A list of more commands is on pages 20 and 21 of the 87A manual (pages
> 40 and 41 in 87A Manual Rev 1.0)
> To clear a Fault 99 on an Alpha 87A amplifier with a PC connected:
> Type in the following commands and enter them for each new line.
> EXT ON
> W B71A FF
> W B71B FF
> W B71C FF
> W B71D FF
> W B71E FF
> W B71F FF
> W B720 FF
> W B721 FF
> W B724 FF
> W B725 FF
> W B726 FF
> W B727 FF
> W B728 FF
> W B729 FF
> W B72A FF
> W B72B FF
> W B72C 0C
> W B72D B5
> W B7E0 FF
> W B7E1 FF
> W B7E2 FF
> W B7E3 FF
> W B7E4 FF
> W B7E5 FF
> W B7E6 FF
> W B7E7 FF
> HF
> SF
> When you type HF and SF they should show all 00. Unplug the 87A from
> the mains power for 30 seconds. This resets the microprocessor. The
> amplifier is now ready for normal use
> ================================
> http://asktheham.com/node/55
> Alpha 87A Fault 8
> published by administrator on Sat, 12/04/2010 - 21:05
> Forums:
> Alpha 87A Entries
> THIS IS VERY, VERY DANGEROUS. IF YOU DON'T HAVE EXPERIENCE WORKING
> AROUND HIGH VOLTAGE, DO NOT - WE REPEAT, DO NOT DO THIS. CALL THE
> COMPANY FOR AN RMA NUMBER, PACK THE AMPLIFIER IN A BOX, AND RETURN IT
> TO US FOR SERVICE. THERE IS A 3,000 VOLT POWER SUPPLY IN THE AMPLIFIER
> THAT CAN EASILY KILL YOU. THERE ARE MULTIPLE POINTS IN THIS AMPLIFIER
> THAT GENERATE LETHAL VOLTAGES. WE REPEAT - UNLESS YOU KNOW EXACTLY
> WHAT YOU ARE DOING WITH THIS, AND YOU'VE WORKED AROUND HIGH VOLTAGES
> BEFORE, DO NOT OPEN THE CASE AND DEFEAT ANY INTERLOCK EVER. (EVER)
> Fault 8 is a problem with the -109vdc PIN diode bias voltage, usually
> caused by the PIN diodes or sometimes the power supply.
> With the POWER OFF, remove the amplifier cover and measure the
> resistance from chassis to the tank coil, there should NOT be a short.
> If there is, that will cause a Fault 8 because the -109 goes through
> the two resistors mounted on the left side of the chassis. Check the
> small blue capacitor from bandswitch to the chassis located near the
> little circuit board on the chassis, left side. This should NOT be
> shorted, it should be a high resistance. If it is close to zero ohms,
> then there is something shorting to ground in the RF section of the
> amplifier. Also Check diode D1 (1N5404) on the Safety Choke Board,
> mounted on the chassis near the two resistors.
> Defeat BOTH interlocks. Put the plastic cap of a Bic pen on the screw
> of the HV shorting spring to insulate it.
> Connect the 87A to AC power and turn it on. Be VERY CAREFUL, there is
> 3000v in the power supply and on the tubes!
> 1) Measure the -109vdc at either end of the large resistor mounted on
> the chassis at the left side of the RF section. If it is below 89
> volts when receiving, that is causing the fault, check PIN diodes.
> First remove the end of the coax cable on the little circuit board
> (Safety Choke Board), turn on the amp and measure -109 again. If
> normal (above -89vdc) there is a bad Power PIN diode (on the ABX-X220
> board in the T/R Module). Reconnect coax center to Safety Choke Board.
> 2) Pull connector J12 (5 pin connector) at edge of Low Voltage Power
> Supply and measure for -109 on J5-2,3, if OK put back on. This can be
> difficult to do with transformer installed in amp, as an option go to
> step 3.
> 3) Pull connector J1 on Input T/R board (under tube deck), measure
> -109v there (P1-3, measure on cable connector not circuit board). If
> bad, problem is usually in LVPS. Plug in connector and measure again,
> if voltage is good at J1 but bad at Safety Choke Board, it may be a
> shorted Q2 (Input T/R Board). Go to step (4) before changing Q2, it is
> turned on/off by the +/-30v.
> 4) Measure +/- 30v on connector in T/R module, J2-2,3. It should be
> +30v when NOT keyed, and -30v when keyed.
> To check the PIN diodes one end must be lifted from the circuit. The
> multimeter must be in the NORMAL resistance measuring range, NOT the
> "diode check" function.
> The forward resistance will vary a bit depending on the voltage that
> the meter puts across the leads in the resistance measuring function.
> We usually use Fluke 77 meters, and they use 0.750vdc when measuring
> resistance, and 2.5vdc in the diode check range. I have another meter
> here that uses only 0.25vdc in the resistance function, and it reads a
> good diode ever higher (about 1.5 megohm) in forward bias. Measure
> your meter in the normal resistance check function with another in the
> volts range to check the bias voltage that is used (leads connected
> together).
> The tan/yellow diodes in the T/R module are KS1001 types, and with one
> end lifted and 0.75vdc from the meter used to forward bias it, they
> read 1.5 megohm. If yours are reading 10k and your meter uses a
> similar voltage on the test leads, then it is leaking too much.
>
> There is also a KS1001 PIN diode under the tube deck that should be
> checked if the other 4 are OK.
> =======================
> http://asktheham.com/node/54
> Alpha 87A Fault 37
> published by administrator on Sat, 12/04/2010 - 21:04
> Forums:
> Alpha 87A Entries
> Fault 37 means that either the bandswitch is just momentarily stuck,
> or there has been a failure on the motor-driver board.
> You can try manually moving the bandswitch to loosen it up. Unplug the
> amp, remove the cover, and turn the white gear on the left side a half
> inch or so. Put cover back on and turn on amp to see if that has
> worked (or defeat BOTH interlocks and turn on with cover off).
> If it stays on, cycle the bandswitch 5 or 6 times by manually
> selecting first 10m, then 160m.
> If the amp is still getting an immediate Fault 37, we will have to
> repair it here, we can give you a Return Authorization number and
> shipping instructions.
> ===================
> http://asktheham.com/node/53
> Alpha 87A Fault 24
> published by administrator on Sat, 12/04/2010 - 21:04
> Forums:
> Alpha 87A Entries
>
> 1) Do you notice that the amp is always on the same band when this
> happens?
> 2) Check the AC mains voltage and what you have the 87A set for. You
> must measure the AC voltage with a digital multimeter, the actual
> voltage must be within +/- 10 vac of what the amp is set for. Your
> line voltage may vary quite a bit from one season to another.
> 3) Unplug the amp and remove the cover. On the AC voltage selection
> terminal strip, the heavy white wire goes on the first of 4 terminals
> and does not move. For 240vac, the other heavy white wire should be on
> the 4th screw terminal (2 empty screws between them).
> 4) Visually check that connector J3 on the right rear edge of the Low
> Voltage Power Supply (LVPS) is plugged onto the pins on the LVPS
> circuit board. This connector is just below the horizontal circuit
> board, and next to the white supporting post. It can be pulled loose
> when installing the transformer. Look at the red connectors in the
> same area of the LVPS to be sure they are all plugged in.
> 5) Measure from the gold-colored resistor on the chassis of the amp
> (left side of RF section) to ground to see if it is shorted to the
> chassis. You should measure 18 ohms across the two parallel resistors.
> The resistance to the chassis on either end should be more than 100
> kohms. If it is too low it will drag down the -109vdc.
> 6) Look carefully at the monoblock HV bridge rectifier on the HV
> circuit board (about 1.5" square, black, 4 leads coming out of it),
> inspect it to be sure there are no burned areas or signs of arcing. If
> it is mounted under the HV circuit board, it may have fallen off the
> board and be shorting to something.
> 7) Check the three resistors R15, R16, R17 (all 1 megohm, measure
> about 667k in the circuit), R20 (measures 3.8k to ground) and R38 (1
> kohm), all located on the left side of the HV circuit board. This is
> the HV monitoring circuit and can cause Fault 24 even if the HV is
> good.
> 8) Check transistors and regulator on the right side of the HV circuit
> board, be sure they are not bent or broken.
> Log in or register to post comments
> mollyh
> Thu, 12/09/2010 - 02:32
> Permalink
> Benign causes of Fault 24
> A spurious Fault 24 can be caused when your 87A has been left
> connected to the mains supply for an extended period of time. Whenever
> the 87A is connected to the mains supply, the micro processor is
> running - a simple brown-out can cause the processor to partially
> reset and generate a fault 24. Although this fault is difficult to
> diagnose and frequently amps with this problem have to return to us
> for repair - about 30% of the time simply unplugging the amp from the
> line voltage to reset it and then letting it warm up normally will
> cure the problem.
> Please also pay particular attention to point 7) above - if the
> metering resistors have failed you'll get a Fault 24 that is really
> easy to diagnose and repair - those resistors look like a string of
> hot dogs.....
> Log in or register to post comments
> N6YW
> Thu, 07/19/2012 - 20:37
> Permalink
> Fault 24
> I have thoroughly gone through my 87A problem child, checked every
> possible known issue and all checks out, including my line voltage
> which never fluctuates more than a few volts during measurement. The
> branch circuit to my shack runs about 30 ft using #10 THHN. During
> operation, under load, my mains voltage drop is only 2 volts compared
> to the amp being off.
> The date codes on my filter capacitors show them all to be late 2001,
> so while I was inspecting the LVPS board, I went ahead and replaced
> the fault 24 cap on IC4. We'll see if that helps or not.
> Otherwise, my head scratching starts all over again. Meanwhile, the
> love/hate relationship with my 87A continues.
> 73 N6YW
> ============================
> http://asktheham.com/node/52
> Alpha 87A Fault 22
> published by administrator on Sat, 12/04/2010 - 21:04
> Forums:
> Alpha 87A Entries
> If the 87A reports a Fault 22, it is usually caused by a blown
> step-start fuse (at the center of the amp next to the AC Voltage
> terminal strip), or can indicate that the 36v power supply fuse is
> blown.
> The 36v fuse is on the Low Voltage Power Supply (LVPS). The fuse is
> marked 125v/2A, it is called the 36v fuse because it is in the 36v
> circuit. The LVPS is under the HV Power Supply, its circuit board is
> vertically mounted.
> This is a small cartridge fuse that plugs into a socket (usually
> white). This can be seen from the right-hand side of the amplifier,
> under the High Voltage board 1/5 in from the top edge and 3/4 in from
> the right-hand edge of the LVPS board. It may measure a few ohms when
> good, but should be less than 10 ohms.
> Another cause of the amp shutting down can be a shorted tube. You can
> test that by either removing the tubes, or by disconnecting the red HV
> lead from the left-rear corner of the HV power supply board. It will
> still get a fault, but should not be a hard fault.
> ====================
> http://asktheham.com/node/51
> Alpha 87A Fault 20 or 18
> published by administrator on Sat, 12/04/2010 - 21:03
> Forums:
> Alpha 87A Entries
> We have found that reseating the connectors on circuit boards may stop
> the erroneous filament current readings.
> Stand the 87A on the right-hand side and remove the plate under the
> tube-deck. Unplug and carefully reconnect the plugs inside the tube
> deck. Also reseat the orange connector on the LVPS (Low Voltage Power
> Supply) directly in front of the power transformer, and just above the
> bottom orange connector that is on one of the transformer cables. Use
> Caig DeOxit contact cleaner (available at Radio Shack) on those
> connectors to ensure a better contact.
> Reseat the two large red connectors on the top edge of the control
> board. They are accessable through the slot in the top-right side of
> the front sub-chassis (behind the LED bargraph displays).
> The Fault 20 may indicate a bad tube or a metering resistor that has
> aged and changed value. With a computer connected to the 87A serial
> port you can use the following commands to see what the filament
> current is (they are always followed by the ENTER key):
>
> Type EXT ON (ENTER) , this puts the amp in the 'factory mode' and will
> let it accept the next command.
> Type ADS FIL (ENTER) numerous times and record the readings. This will
> give you the filament current. It will read some filament current even
> when the 87A is turned off, this is normal and is not a 'real' number
> because the tubes are turned off. The fault limit is 4.0 amps.
> When you are done testing, type EXT OFF to turn off the 'factory mode'
> so that no wrong commands will accidentally be written to the
> microprocessor.
> Once you have completed this process, email the factory with your
> results and for further instructions on possibly changing the filament
> current limits in the amplifier EEPROM
> Log in or register to post comments
> mollyh
> Thu, 12/09/2010 - 02:23
> Permalink
> Fault 20 on the 87A
> Note that although the formal resolution above also talks about a
> possible tube problem - in my 10+ years working directly with Alpha
> amps I have yet to see a Fault 20 that is caused by a bad tube.
> Cleaning the connectors as described above will give you anywhere from
> 6 months to 2 or 3 years more 20-free operating. Eventually you will
> need to get the connectors changed......
> =====================
> http://asktheham.com/node/50
> Alpha 87A Fault 17 and GPIO test
> published by administrator on Sat, 12/04/2010 - 21:03
> Forums:
>
> Alpha 87A Entries
>
> The Fault 17 is a TUNE, or GAIN, fault. If it is happening on all
> bands, it is possibly because of a failed diode (1N5711) in one of the
> wattmeters. There are Input and Output wattmeters.
> Here are some tests.
> 1) Connect PC to serial port with a modem program communicating with
> the amplifier.
> 2) With the 87A in STANDBY, transmit through the amplifier with 100 w
> from the radio to a dummy load (or antenna with low SWR).
> 3) On the PC, type EXT ON.
> 4) On the PC, type GPIO (radio still transmitting 100w). This command
> reports Grid current, Plate current, Input power, and Output power
> each time it is typed. It should be showing about 100w input and about
> 100w output. If one of those is not reading correctly, that indicates
> the wattmeter diodes are damaged.
> -----------------------------------
> To: ve6jy.1 at gmail.com
> Subject: Re: [Amps] Alpha fault 17
> From: K2CB <k2cb at comcast.net>
> Date: Fri, 9 Dec 2016 00:53:30 -0500
> Cc: Amps at contesting.com
> Do a search of the 87A Yahoo group regarding the large L1 choke coil
> on the RF output wattmeter / pin diode / bypass relay module near the
> rear antenna jack. Don't quote me on the exact part designation, as I
> am not at my desk top at the moment, but it is the large green one on
> that board.
> Remove the four screws and shield cover. You will see a large green
> wire wound choke coil. Alpha placed a piece of black foam between the
> coil and circuit board as an insulator.
> This material is breaking down over time, and causing the coil to arc
> over to the ground plane of the circuit board. It will get worse over
> time, and the fault 17 will occur with less and less rf output power
> as time goes on.
> Remove the choke from the board, remove all the old foam pad, clean
> off any carbon on the circuit board from the arcing , and install a
> replacement piece of insulation material. I used some thin black
> plastic. Then reinstall the choke coil.
> If you must remove the entire circuit board, be especially careful
> with the pin diode mounting and associated insulators. They are
> somewhat fragile.
> If you like, I can send you some pictures I took of the last 87A I
> repaired with the same problem. The photos are on my desktop. I can
> send them tomorrow when I get back to my office.
> FYI - Credit is due to Brad from Alpha (or whatever their name is this
> year!) for originally suggesting this as a possible Fault 17 cause.
> Eric
> K2CB
>
> ---------------------------------------
> have you noticed whether the Fault 17 occurs when
> changing bands? If so, here is another note I found in my files from
> Glenn
> at Alpha years ago where a misalignment of the frequency detect can
> lead to
> Fault 17:
>
> 73 es HH
> Jerry NY2KW
>
> ******************************************************
> Alpha 87A Frequency Detect Adjustment:
> The pot in the bottom of the 87A is to be adjusted as follows.
>
> 1. Place the 87A on it's right side.
> 2. Remove the bottom cover under the tubes.
> 3. Place the transceiver on 28mhz and adjust the power output to 5
> watts.
> 4. Place the amplifier in the 160 meters position.
> 5. Put the pot in the full clockwise position to start.
> 6. Key the radio and adjust the pot counter clockwise until the
> amplifier
> changes bands then stop there.
> 7. Replace the covers and place the amp back flat on the table.
> *******************************************************
> From: "Dick Green WC1M" <wc1m73 at gmail.com>
> Date: Fri, 9 Dec 2016 12:48:08 -0500
> Cc: Amps at contesting.com
>
> Some additional points:
>
> - You may not be able to see evidence of arcing until you remove the
> choke.
> - You may need to replace (rewind) the coil. Just count the turns and
> use
> the same gauge/type of wire
> - When my choke coil started arcing, I didn't get fault 17. I got
> faults 8
> and 9 (and 1, I think).
> - This was evidence that the arcing damaged one of the transmit PIN
> diodes,
> which I had to replace.
>
> Don't use the amp until you attend to the choke coil. You don't want
> to risk
> damage to the PIN diodes, which are expensive.
>
> 73, Dick WC1M
> =======================
> http://asktheham.com/node/49
> Alpha 87A Fault 11
> published by administrator on Sat, 12/04/2010 - 21:02
> Forums:
>
> Alpha 87A Entries
>
> Fault 11 usually means that one of the variable capacitors (TUNE or
> LOAD) is shorted, or the PIN diode T-bias voltage is low.
>
> If it faults on all bands, check the 1/4 amp fuse in the Output T/R
> Module. It is a small clear and white fuse that plugs into a white
> socket on the circuit board. Also look for any other burned parts in
> the T/R module whle checking
> the fuse. Look for the leads of PIN diodes recently changed that may
> be touching the chassis?
>
> Fault 11 is fairly unusual and we don't have any set guidelines for
> troubleshooting that, other than tracking down the T-bias circuit. I
> can give you a Return Authorization Number to send here for repair.
> ==============================
> http://asktheham.com/node/48
> Alpha 87A Fault 1 Troubleshooting
> published by administrator on Sat, 12/04/2010 - 21:02
> Forums:
>
> Alpha 87A Entries
>
> THIS IS VERY, VERY DANGEROUS. IF YOU DON'T HAVE EXPERIENCE WORKING
> AROUND HIGH VOLTAGE, DO NOT - WE REPEAT, DO NOT DO THIS. CALL THE
> COMPANY FOR AN RMA NUMBER, PACK THE AMPLIFIER IN A BOX, AND RETURN IT
> TO US FOR SERVICE. THERE IS A 3,000 VOLT POWER SUPPLY IN THE AMPLIFIER
> THAT CAN EASILY KILL YOU. THERE ARE MULTIPLE POINTS IN THIS AMPLIFIER
> THAT GENERATE LETHAL VOLTAGES. WE REPEAT - UNLESS YOU KNOW EXACTLY
> WHAT YOU ARE DOING WITH THIS, AND YOU'VE WORKED AROUND HIGH VOLTAGES
> BEFORE, DO NOT OPEN THE CASE AND DEFEAT ANY INTERLOCK EVER. (EVER)
>
> Alpha 87A Fault 1 Troubleshooting Instructions
>
> Here are troubleshooting instructions for a Fault 1. Be sure to defeat
> both interlocks when turning on the amplifier with the cover off, the
> microswitch and the HV shorting crowbar at the center of the amp! Slip
> the cap from a Bic-type pen over the crowbar screw to insulate it, the
> shorting spring will hold it in place.
>
> These notes apply to firmware v1.08G or 1.00AT, earlier versions may
> not turn on R-bias during warmup.
>
> 1) The receive bias switches when you go from STBY (700 to 900v) to
> OPERATE (less than 1v). When the amp is in OPERATE and keyed, it will
> also be 700v to 900v. Measure at the R BIAS (or R with a line over it)
> terminal on right rear corner of HV Power Supply board.
>
> 2) If the voltage is always lower than 700v, turn off the amplifier,
> remove the connector at R BIAS on the HV Power Supply, and turn the
> 87A back on. If R BIAS is still low the problem is on the HV board,
> either an open resistor at R40-R43 (each 220k/2w or two 470K/1w in
> parallel) or
> a defective Zener diode at D18-D22. Older 87A HV Power Supply boards
> do not have those components on the circuit board, they will be wired
> and suspended above the 2 watt HV bleeder resistors. If R BIAS is 700v
> to 900v with the connector removed and the amplifier turned on, turn
> off the amplifier, put connector back on and proceed to next step.
>
> 3) Remove fuse F2 on the ABX-X180 board (inside the output T/R box)
> and then check 87A again. If it does NOT fault and R-BIAS voltage is
> between 700 and 850 volts, replace D2 and D8. R-BIAS can be measured
> at the back-right corner of the High Voltage Power Supply board, on a
> terminal labeled NOT-R (R with a line over it), or on J4 of the
> ABX-X180 board.
>
> 4) If it DOES fault with F2 removed, lift D6 and D11 diode chain on
> the ABX-X180 board. If the 87A does not fail and R BIAS voltage is
> between 700 and 900 volts, replace D6 and D11.
>
> 5) Lift R5 on the ABX-X180 board and measure to make sure it is not
> open. R5 is located below the large 2.5 mH 'safety choke' mounted on
> the front edge of the T/R compartment.
>
> Note: When replacing the diodes, be careful not to have the leads
> protruding too far below the circuit board, it is possible for them to
> touch the chassis (gnd).
>
> 6) Replace D16 on the HV P/S board, ABX-X177. It can leak and slow
> down the bias switching.
>
> On the HV POWER SUPPLY BOARD drawing #SXX-X161 (in the complete set of
> 87A schematics) transistors Q3 and Q4 (schematic Rev I) may cause the
> bias to stop switching (Q4 on schematic Rev K). They may also be the
> problem if the bias does not switch at all.
> ===============================
> http://asktheham.com/node/47
> Alpha 87A Communications
> published by administrator on Sat, 12/04/2010 - 21:01
> Forums:
>
> Alpha 87A Entries
>
> Please unplug the 87A for 1 minute and then plug it back in to the
> 240v. This will reset the microprocessor and can sometimes correct
> erratic operation (possibly caused by stray RF), although it will NOT
> clear hard faults or remove them from the fault log.
>
> The 87A should 'talk' to the PC anytime it is plugged into mains
> power, even when it is turned off. This is the best troubleshooting
> tool that we have. Note that the 20A fuses must be good.
>
> Below are some notes about the 87A fault protection.
>
> Please remember that when the 87A gets a hard fault and then the power
> is turned back on, it will report the fault for 30 seconds and then
> clear automatically. You must not turn off the power before the fault
> clears (about 30 seconds), or it will log another hard fault the next
> time the power is turned on. Also remember that six of the SAME hard
> fault shutdowns over ANY period of time (with no other kind of Hard
> fault) will then put the 87A in Fault 99 which locks it up. This
> function was put in the amplifier to prevent any further damage if
> operation was attempted after a failure had occurred.
>
> If you keep turning off the power before a hard fault has cleared, and
> this causes 6 of the same hard faults to be entered in the fault log,
> the 87A will then go into Fault 99 and will not turn on. Also, if the
> 87A is turned on 6 times when it keeps shutting down immediately
> because of a hard fault, it will go into Fault 99.
>
> Once the 87A is in Fault 99 condition, each time the ON switch is
> pressed it logs another Fault 99. After 8 times, the original hard
> fault will have been shifted out of the fault log, it will only show
> 99 and not the fault that caused the original problem.
>
> Here are instructions for setting up HyperTerm that is built into Win
> 95/98 for the communications.
>
> To find out what the status of the amplifier is, you need to use a
> modem communications program. Windows 95/98 comes with one called
> HyperTerminal. It is usually located in the ACCESSORIES program group.
> On Win98 it may not have been installed as the default and you can
> install it by inserting the Win98 CD and selecting it in the "Add
> Programs, Communications" menu.
>
> When you click on HyperTerminal from the START, PROGRAMS, ACCESSORIES
> menu it will open a program group on the screen.
>
> Click on HYPERTRM.EXE and it will open a window for a new connection.
> Give it a name, and in the next window select the "Connect Using:
> Direct to COMx" pulldown menu (in the bottom of the box on my version
> of Win95); select the Com port you will use. This is the same one that
> you were using with the AlphaRemote software. If the COM port you
> select is available it will open another box called "COMx Properties".
> Going down the list, select Bps-4800, Data bits-8, Parity-NONE, Stop
> bits-1, Flow control-NONE. Click OK to close the window. Now pull down
> the FILE menu and click PROPERTIES. Click the SETTING tab and then
> click ASCII SETUP at the bottom of the window.
> Click the box for "Echo typed characters locally" (it could have a
> check in the box). Click OK to close both windows.
>
> Plug in the amp (power off) and it should be communicating with the
> computer. Type VER and press the Enter key. The 87A should respondwith
> the firmware version number.
>
> ATTENTION ATTENTION !!!!!!!!!!!!!!
>
> If you see garble (or nothing) you will need to remove pin 22 of the
> 25-pin end of the cable (the 87A end). It is used to set the baudrate
> of the amplifier. Page 19 of the 87A manual has a complete explanation
> of the communications connections.
>
> When it is communicating OK, type SF and HF to display the Soft Fault
> and Hard Fault logs (press Enter key after each command). Save the
> result of those commands.
>
> A list of more commands is on pages 20 and 21 of the 87A manual (pages
> 40 and 41 in 87A Manual Rev 1.0)
> =============
> http://asktheham.com/node/46
> Alpha 87A Bandswitch Alignment
> published by administrator on Sat, 12/04/2010 - 21:01
> Forums:
>
> Alpha 87A Entries
>
> Setting bandswitch positions:
>
> With amplifier turned on, select 10 meter band by pushing switch for
> 28 MHz. Turn amplifier off and remove plug from Mains AC power.
>
> Remove amplifier cover and defeat both interlocks: the microswitch at
> center of amp and the metal spring that will short the HV to chassis
> (insulate the screw in the center of the hole in the spring).
>
> Note the position of the bandswitch fingers, they will be in the
> approximate position of Band 9 (10m) that is needed for the first step
> of realignment.
>
> Plug amplifier into Mains AC but do not turn on.
>
> Establish PC communications with amplifier (use Hyper Terminal or
> other modem program, do NOT use AlphaRemote software). Amplifier power
> is still OFF.
>
> Type "EXT ON" then 'ENTER'.
>
> Type "W B7BB FF" then 'ENTER'.
>
> On the PC, type "AC ON" then 'ENTER'.
>
> The amplifier should come up in the band switch alignment mode with
> only the band-select button 9 (28 MHz) LED flashing. The bandswitch
> will move to the end of its range (past the 10m position)
>
> Referencing the previously noted position for Band 9 (10m), move the
> bandswitch there by pressing the LOAD up/down buttons.
>
> Set each band switch position so that the switch wipers are centered
> by pressing the LOAD up/down buttons. Press 'ENTER' on the amplifier
> front panel to store the selected bandswitch position. The band switch
> will move to the next position and the next lower band-select button
> LED will
> light. After band switch position 1 is set the amplifier will go into
> WAIT mode.
>
> Type "EXT OFF" then 'ENTER'. EXT ON sets the factory mode which allows
> writing to all memory data locations and can be dangerous if left
> enabled.
>
> Turn off amplifier, restore interlocks to normal and put cover back on
> amplifier.
> ================
> http://asktheham.com/node/45
> Alpha 87A Autotune Function
> published by administrator on Sat, 12/04/2010 - 21:00
> Forums:
>
> Alpha 87A Entries
>
> The 87A Autotune (AlphaMax) function is not that of an antenna tuner.
> It constantly monitors the input power, output power, and grid current
> and tunes the motorized TUNE and LOAD capacitors for best efficiency.
> The optimum settings will change as you move across the
> band and if the drive power is changed.
>
> The amplifier measures the frequency of the drive signal and changes
> bands within one second when the radio is keyed on a new frequency. It
> goes to saved settings in memory, and retunes if it is needed. The
> Autotune function of the 87A works at about 30w of drive and higher
> (typically 800w output). It is at this level so that it does not try
> to retune when SSB signals drop between voice peaks.
>
> The 87A has high reflected power protection, tripping to standby if it
> exceeds 225w. This is almost 3:1 VSWR at 1500w output. This is to
> protect the PIN diodes in the T/R circuit from excessive voltages.
> Reducing the output power will allow transmitting into a higher VSWR.
>
> An antenna tuner capable of really handling 1500w under a wide variety
> of loads is almost the same size as the amplifier (like a Nye-Viking
> or Pal-Star tuner). If your antenna has a VSWR of over 3:1 on some
> bands, I would suggest making changes to the antenna(s) or using a
> heavy-duty antenna tuner.
>
> Log in or register to post comments
>
> N6AJR
>
> Sun, 01/30/2011 - 22:04
>
> Permalink
> The 87A and auto tuning
>
> I have noticed a lot of the time when I use my 80 or 160 antenns ( a
> sloper and a Verticle) that as I tune up the band, say from 1.800 to
> 1.835, the amp will show higher and higher reflected power, then will
> automatically adjust itself for a better match, this also happens if
> you raise the power level as you transmit.
>
> I ues my Alpha 87 A mostly in Alpha Max mode, where you press the load
> and enter buttons at the same time and the default ligh blinks ,
> indicating the Alpha Max mode. This makes the amp almost bullet proof.
>
> What a great amp. I have it set up to run on my Orion and most of the
> time I use my 3 element steppir for 10-20 m and my sloper and ver for
> 30 to 160 m. This makes them follow you around the band like a puppy.
> cool
> =============================
> http://asktheham.com/node/44
> Alpha 87A and FT-1000D Power Spike
> published by administrator on Sat, 12/04/2010 - 21:00
> Forums:
>
> Alpha 87A Entries
>
> Use of ALC is OK, but first the radio output must be set to the
> correct level for the output that you want from the amplifier. It is
> not a good idea to use ALC to force the radio output from 100w to the
> needed 50w, for example.
>
> The ALC control on the amplifier should be adjusted so that it limits
> the exciter from going ABOVE the desired level. It is to keep the amp
> from being overdriven and should not be needed if the radio is
> operated correctly.
>
> We do not recommend using the ALC feedback to the radio with modern
> solid-state transceivers. They have an internal ALC circuit that will
> limit the drive from the radio when adjusted correctly, and the
> external
> ALC is not necessary.
>
> Some FT-1000D radios output a spike of full power when first keyed if
> the power sontrols are not set correctly. Using the ALC feedback from
> the amplifier will not stop this because the amp must first be
> overdriven to generate ALC voltage, and the spike is faster than the
> feedback can happen.
>
> Please read these e-mails from the Amps Reflector archive for a
> discussion of the problem by Dick Ehrhorn:
>
> http://lists.contesting.com/pipermail/amps/1999-April/010468.html
>
> http://lists.contesting.com/pipermail/amps/1999-April/010483.html
>
> The trick is to lower both power controls (I think they are called RF
> PWR and DRIVE), instead of just one as the manual instructs. You may
> want to sign onto the Yaesu e-mail list on www.contesting.com and ask
> about it there. I don't have a picture of the FT-1000D front panel
> here, but I know there are two controls for power that must be
> adjusted
> lower to keep down the spike.
>
> Log in or register to post comments
>
> w0ric
>
> Fri, 01/28/2011 - 23:02
>
> Permalink
> ALC
>
> I've never ran the ALC connection. Only the relay cable from the
> 1000-D to the 87A. Seems to be working just fine.
>
> 73
> Rick
> W0RIC
>
> Log in or register to post comments
>
> K4VUD
>
> Sat, 01/29/2011 - 01:27
>
> Permalink
> ALC and 87a
>
> Follow the book.... just do not use ALC. ALC is for whoosies.
>
> Log in or register to post comments
>
> K4VUD
>
> Sat, 01/29/2011 - 01:35
>
> Permalink
> 87a and power spikes
>
> A "power spike" is a flaw in a transceiver whereby it puts out full
> power for a fraction of a second before it settles down to the RF
> power you set with your front panel controls. This is a common flaw in
> many radios, and I have first hand observation of it occurring in the
> K3, FT-897, IC-706, IC-718, and IC-7000. Many hams will tell you that
> these radios NEVER output a power spike, but they are simply thinking
> with love of the radio instead of facts.
>
> The spike will sometimes fool the OH SO TOUCHY Alpha 87a and cause it
> to fault and turn itself to Standby. I do not know what you can do
> about it except sell the radio or the amp and get a better one or
> other.
>
> Be especially careful if you have a 200 watt or 400 watt driver ...
> that is, the tranceiver has this level of RF output.
> ======================
> http://asktheham.com/node/43
> Alpha 87A AC Tap Settings
> published by administrator on Sat, 12/04/2010 - 20:59
> Forums:
>
> Alpha 87A Entries
>
> The AC voltage tap may still be set for 200v, which we have here.
> Measure your line voltage where the amp plugs in, then set the tap
> wire to the appropriate setting. The terminal strip is near the
> step-start fuse at the center of the amp.
>
> The first heavy white wire at the front end of the terminal does not
> move (if you have the optional fan there is also a black wire on the
> same screw). The second white wire moves to the other terminal to
> determine the tap. The second black wire should stay on the lug that
> is 2 positions from the first one (220vac). The 240 screw is 3
> positions
> from the first one (2 empty between the first wire and the 240).
> ======================
> http://asktheham.com/node/42
> Alpha 87A AC Module fuse
> published by administrator on Sat, 12/04/2010 - 20:59
> Forums:
>
> Alpha 87A Entries
>
> On the Simplified Schematic (87A Manual Fig 9) fuse F3 in the AC
> Module is shown as a 500ma fuse. It is really a 100ma fuse and the AC
> module must be removed to check it. If this is blown it will keep the
> 87A from running and it will NOT communicate with the PC via the
> serial port.
>
> To check the fuse, remove the nut at the front of the AC Module and
> the two screws on the rear of the chassis above and below the 20A fuse
> holders. When putting it back in, be sure to tighten the rear screws
> FIRST, then tighten the nut at the front. Doing this in reverse order
> can warp the chassis and may cause the bandswitch to bind up.
> ================
> http://asktheham.com/node/41
> Alpha 87A 40m Clapper Fix
> published by administrator on Sat, 12/04/2010 - 20:58
> Forums:
>
> Alpha 87A Entries
>
> 87A 40m (Segment 1) Clapper Fix
>
> 1) Establish computer communications with amplifier per 87A Operating
> Manual (pages 19-21).
>
> 2) Amplifier plugged in, power OFF.
>
> 3) Type: EXT ON (turns on FACTORY mode)
>
> 4) Type: DM B782[enter] (dump memory at location specified)
>
> a) If first pair of numbers is ØØ then proceed to step 7.
>
> b) If first pair of numbers is BØ type W B782 ØØ[enter]
>
> 5) Unplug 87A AC power, plug back in.
>
> 6) Repeat steps 3) and 4) to verify data written to memory.
>
> 7) Unplug 87A AC power, plug back in.
>
> 8) The amplifier is now ready for normal use.
> ============================
> http://asktheham.com/node/40
> Alpha 87A 17m Testing Bandswitch
> published by administrator on Sat, 12/04/2010 - 20:58
> Forums:
>
> Alpha 87A Entries
>
> A problem with the tuning on 17m can be caused by the bandswitch being
> a little bit out of alignment on that band. To test this, first
> manually select a lower band, then go to 17m. Try transmitting and
> tuning the amp. If you are able to tune it up, save the setting (press
> ENTER and then press the segment that you are on). Then manually
> select a higher band, then go to 17m, and try transmitting again. If
> the tuning changes, or if the 87A gets a Fault 17, it is the
> bandswitch alignment.
>
> We can send you instructions to do it, you will need to have a
> computer communicating with the amp before you can realign the
> bandswitch.
> =================
> http://lea.hamradio.si/~s55o/files/manuals/Alpha%2087a/87A%20Bandswitch%20Tuning.pdf
> FIX FOR ALPHA 87A BANDSWITCH FAULT
> de K6FG
> Many of our members have Alpha 87A amplifiers. Some of us have had a
> problem with recurring faults on one or more bands. Usually the fix
> involves moving to another band, keying down, and then trying again on
> the desired band. The >fault= generally appears with indicator LEDs 1
> & 5 lit. (In my case the problem occurred only on 17 meters.)
> The bad news is that Alpha confirmed that the cause is bandswitch
> misalignment on the particular band. The good news is that the problem
> is easily fixed via software instructions from a computer attached to
> the amplifier's serial port.
> The following are relevant excerpts from Alpha technical support
> emails:
> You will need to have a computer communicating with the amp before you
> can realign the band switch. Here are some notes on the 87A Fault
> protection and instructions for connecting the PC, followed by the 17m
> instructions.
> The 87A should 'talk' to the PC anytime it is plugged into mains
> power, even when it is turned off. This is the best troubleshooting
> tool that we have. Note that the 20A fuses must be good.
> Here are instructions for setting up HyperTerm that is built into Win
> 95/98 for the communications:
> To find out what the status of the amplifier is, you need to use a
> modem communications program. Windows 95/98 comes with one called
> HyperTerminal. It is usually located in the ACCESSORIES program group.
> On Win98 it may not have been installed as the default and you can
> install it by selecting the "Communications" selection on the AWindows
> Setup@ tab on the AAdd Programs@ screen within the Windows AControl
> Panel.@ (You may need to have your Windows installation CD inserted in
> your CD drive.)
> To use the HyperTerminal, click on HyperTerminal from the START,
> PROGRAMS, ACCESSORIES menu.
> Click on HYPERTRM.EXE and it will open a window for a new connection.
> Give it a name, and in the next window select the "Connect Using:
> Direct to COMx" pull down menu; select the Com port you will use. This
> is the same one that you use with the AlphaRemote software.
> If the COM port you select is available it will open another box
> called "COMx Properties". Going down the list, select Bps-4800, Data
> bits-8, Parity-NONE, Stop bits-1, Flow control-NONE. Click OK to close
> the window.
> Now pull down the FILE menu and click PROPERTIES. Click the SETTING
> tab and then click ASCII SETUP at the bottom of the window.
> Click the box for "Echo typed characters locally" (it could have a
> check in the box). Click OK to close both windows.
> Plug in the amp (power off) and it should be communicating with the
> computer.
> Type VER and press the Enter key. The 87A should respond with the
> firmware version number.
> If you see garbage (or nothing) you will need to remove pin 22 of the
> 25-pin end of the cable (the 87A end). It is used to set the baud rate
> of the amplifier. (Page 19 of the 87A manual has a complete
> explanation of the communications connections.)
> Once the amplifier is communicating properly with the computer, type
> SF and HF to display the Soft Fault and Hard Fault logs (press Enter
> key after each command). Save the result of those commands. A list of
> more commands is on pages 20 and 21 of the 87A manual (pages 40 and 41
> in 87A Manual Rev 1.0)
> NOW HERE IS THE PROGRAMMING INFORMATION (Please note that it is for 17
> meters, only):
> The memory address for the 17m band switch position is B7C0 .
> From the terminal program type:
> EXT ON (turns on 'factory mode')
> DM B7C0 (write down first two digits)
> W B7C0 xx (xx = original hex number up or down 2)
> If it [17 meters] works when you come from a lower band, increment the
> number. If it [17 meters] works coming from
> higher band, decrement the number.
> When done type:
> EXT OFF
> The following is a list of memory addresses for all of the band switch
> positions:
> 160m B7BB
> 80m B7BC
> 40m B7BD
> 30m B7BE
> 20m B7BF
> 17m B7C0 (This is a number Azero@, not a letter AO@)
> 15m B7C1
> 12m B7C2
> 10m B7C3
> Personal War Story:
> On my 87A, I raised the B7C0 number by two (from 77 to 79) and my 17
> meter band switch problem completely disappeared.
> The Windows (98SE) terminal program would not recognize COM6 which I
> use to connect to the 87A. Instead of simply (and easily) moving the
> DB9 connector to COM1, 2, 3 or 4, I chose to communicate with the
> amplifier the hard way: I installed a shareware program that
> recognized COM6. That program is Ckubed Terminal Emulation Program.
> It is available at the following website:
> http://ourworld.cs.com/hsc1953/download.htm
> Page 11 SOUTHERN CALIFORNIA DX CLUB August 2003
> ----------------------------------------------------------------------------
> http://asktheham.com/node/39
> Alpha 87A 17m Bandswitch Alignment
> published by administrator on Sat, 12/04/2010 - 20:57
> Forums:
>
> Alpha 87A Entries
>
> The memory address for the 17m bandswitch position is B7C0 .
>
>> From the terminal program type:
>
> EXT ON (turns on 'factory mode')
> DM B7C0 (write down first two digits)
> W B7C0 xx (xx = original hex number up or down 2)
>
> If it works when you come from a lower band, increment the number. If
> it works coming from higher band, decrement the number.
>
> When done type:
> EXT OFF
>
> memory locations for the bandswitch positions:
>
> 160m b7bb
> 80m b7bc
> 40m b7bd
> 30m b7be
> 20m b7bf
> 17m b7c0
> 15m b7c1
> 12m b7c2
> 10m b7c3
> ===========================
> http://asktheham.com/node/38
> Alpha 87A 10m Unlock
> published by administrator on Sat, 12/04/2010 - 20:57
> Forums:
>
> Alpha 87A Entries
>
> 1. Turn on the amplifier; wait until time delay completes.
>
> 2. Select - BAND 1.8 MHz, SEGMENT 1 (far left). Note the green LEDS in
> the
> push-button will illuminate.
>
> 3. When time delay completes switch amplifier to STBY.
>
> 4. Simultaneously depress both DEFAULT and ENTER. If done correctly,
> the green LEDs in the BAND and SEGMENT buttons will go out. If one LED
> is blinking, simultaneously depress both DEFAULT and ENTER again. If
> the LEDs do not go out, it will be necessary to turn off the amplifier
> then turn it back on, waiting for time delay to complete and repeating
> the above steps.
>
> The code sequence for your amplifier is ____-_____-_____-_____.
>
> The nine BAND buttons are designated 1.8, 3.5, 7, 10, 14, 18, 21, 24,
> and 28. The 1.8 button is "1", 3.5 is "2", 7 is "3", and so on.
> Depress the first code sequence button firmly; the LED below the
> button will start blinking when the code number has been read. If the
> LED does not blink, depress the button again. Depress the second
> button; note the blinking LED. Continue with the third and fourth in
> order. When all four digits are entered the amplifier automatically
> unlocks and switches to 28 MHz, you may operate on this band or select
> another. Once unlocked your amplifier will remain so. If you wish to
> re-lock out the ten and twelve meter coverage repeat the code entry
> sequence. You may unlock the coverage again at any time.
> ------------------------------------------
>
> To: Alpha87a at yahoogroups.com
> Subject: [Alpha87a] Alpha 87A 10m / 12m Unlock via Hyperterminal
> From: "Glenn AE0Q gm5bkc at gmail.com [Alpha87a]"
> <Alpha87a at yahoogroups.com>
> Date: Tue, 5 Jan 2016 10:23:40 -0700
>
> Alpha 87A 10m Unlock via Hyperterminal
>
> Instructions to unlock Alpha 87A on 10/12m via serial port:
>
> Connect to serial port using Hyperterminal, amp plugged in but turned
> off.
> Type commands below:
>
> EXT ON
> W B717 00
>
> Then unplug amp from AC power, wait a minute, plug back in.
>
> DO NOT make any mistakes typing, you are writing directly to the
> microprocessor code! Writing to the wrong address will be fatal.
>
> The 87A microprocessor reloads the operating program every time the
> amp is
> plugged in. This can cure some strange operating problems. The amp
> should
> be unplugged from AC power when not in use.
>
> Glenn AE0Q
> Alpha Amplifiers
> RKR DesignsLLC
> =============================
> http://asktheham.com/node/37
> Alpha 87A - Using AlphaMax
> published by administrator on Sat, 12/04/2010 - 20:56
> Forums:
>
> Alpha 87A Entries
>
> When the AlphaMax (Autotune) firmware is installed in the 87A, the
> TUNE and LOAD LEDs will blink to indicate what the AlphaMax program
> would do if it was enabled.
>
> An addendum to the 87A manual was included with AlphaMax kits that
> were installed in the field, or you can download a copy of the new
> version of the 87A manual (with instructions for using AlphaMax) from
> our web site:
>
> http://www.rfconcepts.com
>
> You should tune up the amp with your antennas on each band/segment and
> save the settings in USER memories. You do this by pressing ENTER and
> then while the ENTER LED is flashing, press the segment that you are
> on. When changing bands the 87A first goes to the USER memory setting.
> If further tuning is needed it will make the adjustments if the
> Autotune mode (AlphaMax) is enabled. If it is not enabled, the TUNE
> and/or LOAD LEDs will blink to indicate what direction those would be
> moved.
>
> If it is not in Autotune and the user settings are not at all close to
> desirable, it will fall back to factory-saved default settings (for a
> 50 ohm load) and the DEFAULT LED will light solid.
>
> The Autotune function is enabled by pressing the LOAD^ and ENTER
> buttons at the same time when the amp is in operate and warmed up. The
> DEFAULT LED will flash when Autotune is enabled and the amp is in
> operate and warmed up.
>
> The DEFAULT LED indicates 3 conditions of the amp:
>
> 1) not lit means it is in original 87A function of automatically
> measuring transmitted frequency and recalling memory settings for band
> segment closest to that frequency detected.
>
> 2) blinking means that autotune (AlphaMax) is enabled, amp will
> dynamically retune if drive changes (as when yelling louder than
> normal in a pileup, etc).
>
> 3) lit solid means the factory memory setting has been recalled
>
> Please note that the TUNE meter is a rough indicator to allow the amp
> to be tuned with low drive levels so that it is close to being set for
> 1500w output. Once you increase the drive and are close to 1500w out,
> fine tune by adjusting the TUNE and LOAD controls for maximum output
> at the drive level you are at. This should correspond to a dip in the
> plate current. The TUNE LED may be a number of LEDs off center to
> either side. The most useful multimeter parameter to monitor when
> transmitting is the Ip (plate current), also watching the Ig (grid
> current).
>
> The TUNE meter is calibrated on 20m when the amp is tuned up for 1500w
> out, with new tubes. As the tubes age, it will indicate off center a
> bit. Line voltage that is not at the nominal value for each range
> (200, 220 or 240v) may also affect the TUNE calibration.
>
> Since the 87A has memories that should be saved for the tuneup
> settings for each band segment, the TUNE meter isn't really as useful
> as it is with a manually tuned amp (Alpha 89/91B/99).
> =================
> http://asktheham.com/node/8
>
> ============================================================================
> http://df3cb.com/alpha87a/documentation/commands.php
>
> Reference: Alpha 87A Command
>
> HELP:
> AC STAT HF
> SF PANEL SER
> DATE VER HNDSHK
> DM ANTENNA BYE
> OPER MODE BAND
> SEG TUNE LOAD
> FREQ DEF ENT
> METER PWR REFL
> GRID LOCK AD
> ADS GPIO AUTOTUNE
>
>
> Power On/Off Command
>
> Command Description
> AC Is AC power on or off?
> AC ON Turns AC power on
> AC OFF Turns AC power of
>
>
> Set Commands
>
> Command Description
> BAND # (1-9) Sets band switch to any band one through nine
> DEF Sets tune, load and frequency to default or factory
> settings
> ENT Use with SEG command for saving data
> FREQ # (in kHz) Sets up unit for this entered frequency
> LOAD DOWN Adjusts load capacitor down one step
> LOAD UP Adjusts load capacitor up one step
> METER HV Sets multimeter to HV mode & reports value
> METER IP Sets multimeter to IP mode & reports value
> METER TUNE Sets multimeter to TUNE mode & reports value
> MODE HIGH Sets high voltage power supply to high mode
> MODE LOW Sets high voltage power supply to low mode
> OPER OFF Sets to standby mode
> OPER ON Sets to operate mode if ready
> SEG # (1-5) Sets segment to entered value
> TUNE DOWN Sets tune capacitor down one step
> TUNE UP Sets tune capacitor up one step
>
>
>
> Poll Commands
>
> Command Description
> STAT Reports unit status
> PWR Reports current forward power out in watts
> REFL Reports current load reflected power in watts
> METER Reports current reading of the front panel multimeter
> GRID Reports current grid current in mA
>
> FREQ What frequency is the unit on or last frequency used?
> LOAD Reports current load capacitor setting (0-100)
> MODE Reports current HV power supply setting, HI or LO
> OPER Reports whether in operate or standby
> SEG Reports current segment setting
> TUNE Reports current tune capacitor setting (0-100)
>
>
>
> STAT Unit Status Report
>
> ????????????????????
> STATE = OFF MODE = LOW
> 10-METER ENABLED PANEL ENABLED
> FREQUENCY = 18150 kHz
> BAND = 6 SEGMENT = 3
> TUNE = 40 LOAD = 70
> ANTENNA = 5
> ????????????????????????????
>
>
> Report Example Power off Example Power
> on Upon 240VAC
> ------ ----------------- ---------------- -----------
> state warm-up (AC) AMPLIFIER IS OFF (AC ON)
> AMPLIFIER IS ON
> standby, or operate: HV mode, low or high (STAT) STATE =
> OFF MODE = LOW ALPHA 87A ALPHA 87A
> 24-30 MHz enabled or disabled 10-METER
> ENABLED PANEL ENABLED VERSION UPX-X108-G VERSION
> 1.00-AT
> panel enabled or disabled FREQUENCY =
> 14000 kHz COPYRIGHT 1992 COPYRIGHT
> 1992, 1999
> frequency last entered BAND = 5
> SEGMENT = 1 ETO, INC. ALPHA/POWER,
> INC.
> band last selected TUNE = 48 LOAD
> = 57 POWER ON SEQUENCE POWER ON SEQUENCE
> segment last used USER
> tune and load capacitor positions 3
> MINUTE WARM-UP
> NOT VALID DURING WARM-UP
> ...
> MODE = HIGH
> STATE = STANDBY
> STATE = OPERATE
> ???????????????????????????????????????????????????????
>
> Nov 8, 2014:
> HF:
> HFAULT LOG = 24 24 24 22 37 37 24 24 HF bridge arc to PCB
> fixed with fishpaper shield
>
> SF:
> SFAULT LOG = 17 17 17 17 17 17 17 17
>
>
> Reference: Alpha 87A Fault Codes
>
>
>
> Code Type Description
> 1 Soft Receive PIN back bias voltage not at minimum
> required level with key down and no RF drive.
> 2 Hard Five volt supply voltage too low.
> 3 Hard Five volt supply voltage too high.
> 5 Hard Plate voltage abnormally low.
> 6 Hard Plate voltage abnormally high.
> 7 Soft Cathode and/or power PIN diode back bias
> (-109V) not switching to the required low level with key down.
> 8 Soft Transmit PIN diode back bias below minimum
> required value key up.
> 9 Soft Transmit PIN diode forward current below
> minimum required value key down.
> 11 Soft Transmit PIN diode forward current exceeds
> maximum limit key down.
> 12 Soft Excessive input reflected power.
> 13 Soft Excessive and unsafe drive power.
> 14 Soft Excessive load reflected power or RF voltage.
> May be caused by excessive load VSWR at an otherwise acceptable power
> (e.g. 4:1 at 1.5 kW)
> or excessive power at otherwise acceptable
> load VSWR (e.g. 2.5 kW at 1.9:1).
> 16 Soft Plate current greater than 1.35 amp for more
> than 4 seconds continuous. Note: The IP button LED flashes for several
> seconds before a fault 16 IP trip occurs.
> 17 Soft Abnormally low or high amplifier power gain.
> Usually due to extreme mis-tuning or possibly an RF arc. (XCVR drive
> too high)
> 18 Soft Filament current less than 2.0 amp. Possible
> open tube filament.
> 20 Soft Filament current greater than 3.5 amp.
> Possible shorted filament.
> 21 Soft Excessive tube temp. in transmit (key down);
> abnormal dissipation and/or insufficient airflow.
> 22 Hard Control system fault; D/A feedback) not
> working.
> 23 Hard Control system fault; D/A feedback 1 not
> working.
> 24 Hard System voltage fault. High voltage, +/-15
> volts, or 109 volts below safe operating level. (HF bridge arc to PCB)
> 26 Soft RF drive before or without amplifier keyed
> (possibly mis-sequenced T/R), or attempted automatic band change with
> excessive RF drive.
> 29 Soft Attempt to transmit on invalid frequency, such
> as above 24 MHz without unlocking 24-30 MHz coverage.
> 31 Soft Excessive grid current; above 100mA
> continuously for 2 seconds. NOTE: Red LED in IG bargraph flashes
> before IG trip occurs.
> 33 Soft Control system fault; TUNE capacitor not
> initializing.
> 34 Soft Control system fault; TUNE capacitor not
> moving or zero sensor position not working.
> 35 Soft Control system fault; LOAD capacitor not
> initializing.
> 36 Soft Control system fault; LOAD capacitor not
> moving or zero sensor not working.
> 37 Hard Control system fault; Bandswitch not moving.
> 99 Fault 99 Unit refuses to turn on. Same hard fault
> occured 6 consecutive times without one successful power-up.
>
>
> February 2, 2014:
> To clear a Fault 99 on an Alpha 87A amplifier with a PC connected:
> Type in the following commands and enter them for each new line.
>
> EXT ON
> W B71A FF
> W B71B FF
> W B71C FF
> W B71D FF
> W B71E FF
> W B71F FF
> W B720 FF
> W B721 FF
> W B724 FF
> W B725 FF
> W B726 FF
> W B727 FF
> W B728 FF
> W B729 FF
> W B72A FF
> W B72B FF
> W B72C 0C
> W B72D B5
> W B7E0 FF
> W B7E1 FF
> W B7E2 FF
> W B7E3 FF
> W B7E4 FF
> W B7E5 FF
> W B7E6 FF
> W B7E7 FF
> HF
> SF
>
> When you type HF and SF they should show all 00. Unplug the 87A from
> the mains power for 30 seconds.
> This resets the microprocessor. The amplifier is now ready for normal
> use
> ==========================================
>
> Archived Ask The Ham web site:
> https://web.archive.org/web/20130805035808/http://asktheham.com/forum/8
> https://web.archive.org/web/*/http://asktheham.com/forum/*
> -----------------------------------------------------------------------------------------
>
>
>
>> On Tue, 30 Jul 2019 11:37:14 -0400, Dave <rocketnj at gmail.com> wrote:
>>
>> Hi all
>>
>> Looking at an old 87A for a friend.
>> This is a 91xxx s/n without AlphaMax and NO updates done to amp.
>>
>> Originally faulting with fault 8. Replaced bad RX PIN diodes with 1N4007 diodes and TX PIN with pair of UM4006D. No more fault 8.
>>
>> Now whenever you press TUNE DOWN it immediately faults with fault 33. (Tune motor failed to initialize).
>>
>> Another clue is on power up both Load
>> LEDs flash but only the TINE UP LED flashes twice. (Tune down does not flash). But Tune Down LED does light when pressing Tune Down.
>>
>> Any ideas appreciated
>>
>> Dave wo2x
>>
>> Sent from my waxed string and tin cans.
> <87a_commands.txt>
> <87a_fuses.txt>
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