[Amps] Henry 2KD amp FIX
W8HW
w8hw at att.net
Thu May 26 18:32:54 PDT 2011
I have seen this many times. More than one cause. One cause that I have seen
often is a tube goes gassy and arks over. It takes out the metering
resisters and grid current often gets affected by this. It is easy to spot
this as the resistors split and go into pieces. If memory serves me those
resistors() are in the front panel near multi meter switch (if memory serves
me). I should have looked up my service manual for that unit to be sure, but
I did not, so this is just from memory.
As far as the diode showing "13.5 K ohm" that can be the fault of you ohm
meter. Most modern ohm meters do not use enough voltage to turn on a diode
or transistor for testing. You will have to use a higher voltage. Consider
using a 1k resistor in series with the diode and applying 12vdc one
direction you will have no current draw and the other you will have current.
You will see around .6 volts across the diode in one direction and 12 volts
in the other.
If you need manual, feel free to email me direct (email below) and I will
email you a copy.
73, Bruce, W8HW, w8hw at att.net
I FIX broken radios. If it transmit, I fix it.
----- Original Message -----
From: <amps-request at contesting.com>
To: <amps at contesting.com>
Sent: Thursday, May 26, 2011 8:38 PM
Subject: Amps Digest, Vol 101, Issue 39
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> Today's Topics:
>
> 1. Re: Henry 2KD-5 Problem (TexasRF at aol.com)
> 2. Re: Henry 2KD-5 Problem (Mitch Cox)
> 3. Re: Henry 2KD-5 Problem (TexasRF at aol.com)
> 4. Re: Henry 2KD-5 Problem (Jim W7RY)
> 5. Re: Henry 2KD-5 Problem (Mitch Cox)
> 6. 8877 or 3CPX1500 Wanted (Jim W7RY)
> 7. Re: Henry 2KD-5 Problem (k7fm)
> 8. Re: T/R relay (Paul Decker)
> 9. Re: T-T Titan with Pro III Question (Jim Brown)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 26 May 2011 18:38:01 EDT
> From: TexasRF at aol.com
> Subject: Re: [Amps] Henry 2KD-5 Problem
> To: kb5gt at cableone.net, amps at contesting.com
> Message-ID: <ece6c.3508e002.3b103049 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> Hi Ed, sounds like a leakage to ground somewhere on the B+ side of the
> plate supply. Perhaps a HV feed through lost it's insulation or plate
> bypass or
> some other component in the B+ circuit has developed a leakage path to
> chassis/ground.
>
> 73,
> Gerald K5GW
>
>
>
>
> In a message dated 5/26/2011 5:18:23 P.M. Central Daylight Time,
> kb5gt at cableone.net writes:
>
> Last night I was using my 2KD-5, and it was working fine. After making
> several transmissions with no problem, it made a loud pop when keyed. Now
> the grid current indication goes off scale in the negative direction as
> soon
> as it is turned on, and stays there even with drive applied. It also has
> plate current flowing ( about 300 mA ) even when not keyed. It is still
> working and has output.
> I have to get someone to move it to my workbench due to a back injury, so
> all I've done so far is to remove the top. The bias diode reads 13.5 Kohm
> in
> both directions when checked with one end of the 220 Ohm parallel
> resistor
> lifted, but I see nothing that made the loud pop, so far.
> When I get it on the bench I can get into it, but wondered if anyone else
> had seen these problems in this or a similar amplifier.
> Thanks & 73,
> Ed, KB5GT
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
>
> ------------------------------
>
> Message: 2
> Date: Thu, 26 May 2011 18:41:20 -0400
> From: "Mitch Cox" <ww4cox at embarqmail.com>
> Subject: Re: [Amps] Henry 2KD-5 Problem
> To: <TexasRF at aol.com>, <kb5gt at cableone.net>, <amps at contesting.com>
> Message-ID: <AA38700EC7BF4808AF905539B1F15E63 at w4cox057538544>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Grid to filament short in one tube.
> ----- Original Message -----
> From: TexasRF at aol.com
> To: kb5gt at cableone.net ; amps at contesting.com
> Sent: Thursday, May 26, 2011 6:38 PM
> Subject: Re: [Amps] Henry 2KD-5 Problem
>
>
> Hi Ed, sounds like a leakage to ground somewhere on the B+ side of the
> plate supply. Perhaps a HV feed through lost it's insulation or plate
> bypass or
> some other component in the B+ circuit has developed a leakage path to
> chassis/ground.
>
> 73,
> Gerald K5GW
>
>
>
>
> In a message dated 5/26/2011 5:18:23 P.M. Central Daylight Time,
> kb5gt at cableone.net writes:
>
> Last night I was using my 2KD-5, and it was working fine. After making
> several transmissions with no problem, it made a loud pop when keyed.
> Now
> the grid current indication goes off scale in the negative direction as
> soon
> as it is turned on, and stays there even with drive applied. It also has
> plate current flowing ( about 300 mA ) even when not keyed. It is still
> working and has output.
> I have to get someone to move it to my workbench due to a back injury,
> so
> all I've done so far is to remove the top. The bias diode reads 13.5
> Kohm
> in
> both directions when checked with one end of the 220 Ohm parallel
> resistor
> lifted, but I see nothing that made the loud pop, so far.
> When I get it on the bench I can get into it, but wondered if anyone
> else
> had seen these problems in this or a similar amplifier.
> Thanks & 73,
> Ed, KB5GT
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
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> Checked by AVG - www.avg.com
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>
> ------------------------------
>
> Message: 3
> Date: Thu, 26 May 2011 18:41:14 EDT
> From: TexasRF at aol.com
> Subject: Re: [Amps] Henry 2KD-5 Problem
> To: ww4cox at embarqmail.com, kb5gt at cableone.net, amps at contesting.com
> Message-ID: <ed02a.40e9d096.3b10310a at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> Which can be confirmed by removing the tube(s).
>
> 73,
> Gerald K5GW
>
>
>
> In a message dated 5/26/2011 5:32:26 P.M. Central Daylight Time,
> ww4cox at embarqmail.com writes:
>
> You have a shorted tube.
> ----- Original Message -----
> From: ED MCKIE
> To: amps at contesting.com
> Sent: Thursday, May 26, 2011 6:18 PM
> Subject: [Amps] Henry 2KD-5 Problem
>
>
> Last night I was using my 2KD-5, and it was working fine. After making
> several transmissions with no problem, it made a loud pop when keyed. Now
> the grid current indication goes off scale in the negative direction as
> soon
> as it is turned on, and stays there even with drive applied. It also has
> plate current flowing ( about 300 mA ) even when not keyed. It is still
> working and has output.
> I have to get someone to move it to my workbench due to a back injury, so
> all I've done so far is to remove the top. The bias diode reads 13.5 Kohm
> in
> both directions when checked with one end of the 220 Ohm parallel
> resistor
> lifted, but I see nothing that made the loud pop, so far.
> When I get it on the bench I can get into it, but wondered if anyone else
> had seen these problems in this or a similar amplifier.
> Thanks & 73,
> Ed, KB5GT
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1375 / Virus Database: 1509/3660 - Release Date: 05/25/11
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
>
> ------------------------------
>
> Message: 4
> Date: Thu, 26 May 2011 15:42:28 -0700
> From: "Jim W7RY" <w7ry at inbox.com>
> Subject: Re: [Amps] Henry 2KD-5 Problem
> To: "Mitch Cox" <ww4cox at embarqmail.com>, "ED MCKIE"
> <kb5gt at cableone.net>, <amps at contesting.com>
> Message-ID: <AF3C55E264804E5BB5FEB5CAA92E12AF at Laptop>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Agreed!
>
> But you can't just pull one tube at a time because the filaments are in
> series. You most likely have other parts destroyed by the tube short.
>
>
> 73
> Jim W7RY
>
>
>
> --------------------------------------------------
> From: "Mitch Cox" <ww4cox at embarqmail.com>
> Sent: Thursday, May 26, 2011 3:32 PM
> To: "ED MCKIE" <kb5gt at cableone.net>; <amps at contesting.com>
> Subject: Re: [Amps] Henry 2KD-5 Problem
>
>> You have a shorted tube.
>> ----- Original Message -----
>> From: ED MCKIE
>> To: amps at contesting.com
>> Sent: Thursday, May 26, 2011 6:18 PM
>> Subject: [Amps] Henry 2KD-5 Problem
>>
>>
>> Last night I was using my 2KD-5, and it was working fine. After making
>> several transmissions with no problem, it made a loud pop when keyed.
>> Now
>> the grid current indication goes off scale in the negative direction as
>> soon
>> as it is turned on, and stays there even with drive applied. It also has
>> plate current flowing ( about 300 mA ) even when not keyed. It is still
>> working and has output.
>> I have to get someone to move it to my workbench due to a back injury,
>> so
>> all I've done so far is to remove the top. The bias diode reads 13.5
>> Kohm
>> in
>> both directions when checked with one end of the 220 Ohm parallel
>> resistor
>> lifted, but I see nothing that made the loud pop, so far.
>> When I get it on the bench I can get into it, but wondered if anyone
>> else
>> had seen these problems in this or a similar amplifier.
>> Thanks & 73,
>> Ed, KB5GT
>> _______________________________________________
>> Amps mailing list
>> Amps at contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1375 / Virus Database: 1509/3660 - Release Date: 05/25/11
>> _______________________________________________
>> Amps mailing list
>> Amps at contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1375 / Virus Database: 1509/3662 - Release Date: 05/26/11
>>
>
>
> ------------------------------
>
> Message: 5
> Date: Thu, 26 May 2011 18:55:47 -0400
> From: "Mitch Cox" <ww4cox at embarqmail.com>
> Subject: Re: [Amps] Henry 2KD-5 Problem
> To: "Jim W7RY" <w7ry at inbox.com>, "ED MCKIE" <kb5gt at cableone.net>,
> <amps at contesting.com>
> Message-ID: <3B9A9C324061445CB29729150B96FA5F at w4cox057538544>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Since the grids are grounded to the chassis most likely got a meter shunt
> resistor or 2.
> ----- Original Message -----
> From: Jim W7RY
> To: Mitch Cox ; ED MCKIE ; amps at contesting.com
> Sent: Thursday, May 26, 2011 6:42 PM
> Subject: Re: [Amps] Henry 2KD-5 Problem
>
>
> Agreed!
>
> But you can't just pull one tube at a time because the filaments are in
> series. You most likely have other parts destroyed by the tube short.
>
>
> 73
> Jim W7RY
>
>
>
> --------------------------------------------------
> From: "Mitch Cox" <ww4cox at embarqmail.com>
> Sent: Thursday, May 26, 2011 3:32 PM
> To: "ED MCKIE" <kb5gt at cableone.net>; <amps at contesting.com>
> Subject: Re: [Amps] Henry 2KD-5 Problem
>
> > You have a shorted tube.
> > ----- Original Message -----
> > From: ED MCKIE
> > To: amps at contesting.com
> > Sent: Thursday, May 26, 2011 6:18 PM
> > Subject: [Amps] Henry 2KD-5 Problem
> >
> >
> > Last night I was using my 2KD-5, and it was working fine. After making
> > several transmissions with no problem, it made a loud pop when keyed.
> Now
> > the grid current indication goes off scale in the negative direction
> as
> > soon
> > as it is turned on, and stays there even with drive applied. It also
> has
> > plate current flowing ( about 300 mA ) even when not keyed. It is
> still
> > working and has output.
> > I have to get someone to move it to my workbench due to a back
> injury,
> > so
> > all I've done so far is to remove the top. The bias diode reads 13.5
> Kohm
> > in
> > both directions when checked with one end of the 220 Ohm parallel
> > resistor
> > lifted, but I see nothing that made the loud pop, so far.
> > When I get it on the bench I can get into it, but wondered if anyone
> > else
> > had seen these problems in this or a similar amplifier.
> > Thanks & 73,
> > Ed, KB5GT
> > _______________________________________________
> > Amps mailing list
> > Amps at contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 10.0.1375 / Virus Database: 1509/3660 - Release Date:
> 05/25/11
> > _______________________________________________
> > Amps mailing list
> > Amps at contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 10.0.1375 / Virus Database: 1509/3662 - Release Date: 05/26/11
> >
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1375 / Virus Database: 1509/3660 - Release Date: 05/25/11
>
>
> ------------------------------
>
> Message: 6
> Date: Thu, 26 May 2011 16:24:55 -0700
> From: "Jim W7RY" <w7ry at inbox.com>
> Subject: [Amps] 8877 or 3CPX1500 Wanted
> To: "AMPS" <amps at contesting.com>
> Message-ID: <8336913116354E7B992FFE992DC1E351 at Laptop>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Does anyone have a excellent 8877 or 3CPX1500 tube for sale? Please let
> me know. I'm shopping around right now. w7ry at arrl . net
>
> Thanks
> 73
> Jim W7RY
>
>
> ------------------------------
>
> Message: 7
> Date: Thu, 26 May 2011 17:20:27 -0700
> From: "k7fm" <k7fm at teleport.com>
> Subject: Re: [Amps] Henry 2KD-5 Problem
> To: "ED MCKIE" <kb5gt at cableone.net>, <amps at contesting.com>
> Message-ID: <2E73337362E3493FA2F4D5B3F53A6B95 at COLIN>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> "The bias diode reads 13.5 K ohm in both directions when checked with one
> end of the 220 Ohm parallel resistor
> lifted,"
>
> Ed, a normal dvm will check a single diode, but when you have diodes in
> series, as in a bias diode, the normal dvm will not work. Say you have 7
> diodes in series, the voltage drop would be 4 - 5 volts, so you need more
> than that to overcome the drop.
>
> A 9 volt battery as a source should work ok. One direction, the meter
> will
> read 4 volts, the other direction it will read zero.
>
> 73, Colin K7FM
>
>
>
> ------------------------------
>
> Message: 8
> Date: Fri, 27 May 2011 00:36:12 +0000 (UTC)
> From: Paul Decker <kg7hf at comcast.net>
> Subject: Re: [Amps] T/R relay
> To: amps at contesting.com
> Message-ID:
> <509589696.809743.1306456572487.JavaMail.root at sz0009a.westchester.pa.mail.comcast.net>
>
> Content-Type: text/plain; charset=utf-8
>
>
>
>
>
> Thanks Steve, that is kinda what I figured.? I thought I tried them at VHF
> and didn't have any luck getting them to work.
>
>
>
> I found this one on digikey, it's a bit expensive though:
>
> http://search.digikey.com/scripts/dksearch/dksus.dll?Detail&name=PB1252CT-ND
>
>
>
> For that price I might as well get another tohtsu CX-140 or something like
> that.
>
>
>
>
>
> Paul
>
>
>
>
>
>
>
>
>
>
>
>
>
> ?? 5. Re: T/R relay (Steve Thompson)
>
> Date: Thu, 26 May 2011 22:45:24 +0100
> From: Steve Thompson <g8gsq72 at gmail.com>
> Subject: Re: [Amps] T/R relay
> To: amps at contesting.com
> Message-ID: <4DDEC9F4.2050908 at gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> I've used similar types at VHF with bits of capacitance to tune
> out the inductance of the internals but found them too touchy at
> UHF. There's also the issue of skin effect and how plating behaves
> at higher frequencies.
>
> For just a few $ you can get relays like Omron G6Y/G6Z which are
> rated for 1 or 2GHz. I can't recall part numbers but I'm sure some
> ??of them (maybe Siemens/NAIS/Aromat brand) are rated for 10 or
> 20W at UHF.
>
> Steve
>
>
>
>
> ------------------------------
>
> Message: 9
> Date: Thu, 26 May 2011 17:38:32 -0700
> From: Jim Brown <jim at audiosystemsgroup.com>
> Subject: Re: [Amps] T-T Titan with Pro III Question
> To: amps at contesting.com
> Message-ID: <4DDEF288.1050505 at audiosystemsgroup.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> On 5/26/2011 9:02 AM, Bob Arenella wrote:
>> Anyone using a Titan 425 with a Pro III? Is it necessary to use a
>> keying buffer between the rig& amp?
>
> The control inputs of the Titan 425 are the base of a chip that you pull
> to ground to put in TX mode. It draws VERY little current, and it's not
> bitchy about how good the pull to ground is.
>
> You can download pdf schematics at
> http://audiosystemsgroup.com/publish.htm
>
> There CAN be an issue with TIMING of the keying. The Titan won't let you
> transmit until the TR relay has pulled in, and that takes about 8-10
> msec. Most modern rigs have that delay built in -- they delay RF output
> by approximately that amount after the DC keying signal for the amp.
> Dunno about the Pro III in that regard. My Titans are fine with TS850,
> FT1000MP, K2, and K3, even doing full QSK. I don't run QSK much
> anymore, because I do lots of contesting and would have to replace
> relays every few years. I've gotten lazy in my old age.
>
> 73, Jim K9YC
>
>
>
> ------------------------------
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> End of Amps Digest, Vol 101, Issue 39
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