OK.
There are other things that can go wrong with the A9 board so I am still
focused on it.
Can you put a voltmeter on the 5 volt line as you vary the 13.8 volt input? It
should not change very much. This was not the best 5 volt switching supply
anybody ever designed bu tit generally should be able to hold within 200 mV
when varying the input from ~12 to ~15 volts.
Gary
W0DVN
> On Sep 23, 2022, at 3:37 PM, Bob, W3IDT <w3idt@comcast.net> wrote:
>
> A9 capacitors have been replaced.
> Sorry, should have said so in the email.
>
> Bob, w3idt
>
> .......
> . Robert F. Teitel, W3IDT
> .
> . w3idt@comcast.net
> . w3idt@arrl.net
> ........
>
> On 9/23/2022 4:05 PM, dukeshifi wrote:
>> If an Orion is voltage sensitive in any way, change the electrolytic
>> capacitors on the A9 Power Distribution Board, ALL OF THEM.
>> 90% of the time, tis will resolve the issues.
>> Gary
>> W0DVN
>> PS: This is the same advice you would get from Ten Tec service, back when
>> you could call them on the phone...
>>> On Sep 23, 2022, at 1:35 PM, Bob, W3IDT <w3idt@comcast.net> wrote:
>>>
>>> Some time ago I asked about an issue I was having with my Orion II:
>>> The RX would stop after TX with FT* or SSB above about 10 watts (CW at 100
>>> watts was fine). Only a power down/up cycle would unlock the RX. RFI was
>>> suspected, but it is not the cause.
>>>
>>> Steve, NY3A, with a complete test shop, has been digging into the issue.
>>> He has discovered two problems. I am asking for any knowledge or advice on
>>> either one.
>>>
>>> 1. The problem almost never happens if the input power supply is below
>>> about 13volts. Almost always happens at 14.5volts. So, there is something
>>> that seems very input voltage sensitive, though the various voltage
>>> regulators all seem OK.
>>>
>>> 2. The proximate cause of the RX shutdown is the "REF-IN" signal from the
>>> CPU going "low"... As Steve says,
>>> ---------------
>>> VCO1 and 2 are unlocking. The reason they're unlocking is their reference
>>> is going away. The reference is a DDS, direct digital synthesizer. The
>>> reason it's going away is the REF_EN signal is going low. This removes a
>>> crystal oscillator reference signal from the DDS. This REF_EN sig comes
>>> directly from the microprocessor board.
>>> --------------------
>>>
>>> Steve's complete message (and earlier messages) copied below.
>>>
>>> Does anyone have a clue as to the cause of the REF-IN signal going low? OR
>>> about the voltage sensitivity?
>>>
>>> Any advice greatly appreciated.
>>>
>>> Bob, w3idt
>>>
>>> .......
>>> . Robert F. Teitel, W3IDT
>>> .
>>> . w3idt@comcast.net
>>> . w3idt@arrl.net
>>> ........
>>>
>>>
>>> -------- Forwarded Message --------
>>> Subject: RE: Status /Orion II
>>> Date: Thu, 25 Aug 2022 21:42:30 +0000
>>> From: Steve S <NY3A@hotmail.com>
>>> To: w3idt@comcast.net <w3idt@comcast.net>
>>>
>>>
>>>
>>> Made progress today.
>>>
>>> VCO1 and 2 are unlocking. The reason they're unlocking is their reference
>>> is going away. The reference is a DDS, direct digital synthesizer. The
>>> reason it's going away is the REF_EN signal is going low. This removes a
>>> crystal oscillator reference signal from the DDS. This REF_EN sig comes
>>> directly from the microprocessor board.
>>>
>>> This happens only at higher Power Supply voltage. I've been testing it at
>>> 14.5-14.7V. The manual says the upper limit is 15V. It unlocks is either
>>> rcv or xmit at this higher voltage.
>>>
>>> So why is the micro pulling this sig low at higher PS voltage? Sometimes
>>> there is a PLL unlock signal which if true, triggers radio shutdown. I see
>>> no such signal from the PLL. Bottom line is I don't know right now. If Ten
>>> Tec was around I'd send email that software guy would eventually see, and
>>> he could tell me.
>>>
>>> I started signup for Ten Tec group on Groups.io forum and will ask what
>>> triggers Ref En shutdown and will see if anyone knows. Odds are slim, but
>>> hopeful.
>>>
>>> Possibly there is A/D monitoring PS voltage through voltage divider
>>> somewhere, or micro PS may have issue. This seems unlikely since micro
>>> seems to be running fine otherwise.
>>>
>>> In any case, standby...
>>>
>>>
>>> -------- Original message --------
>>> From: "Bob, W3IDT" <w3idt@comcast.net>
>>> Date: 8/25/22 4:49 PM (GMT-05:00)
>>> To: Steve S <ny3a@hotmail.com>
>>> Subject: Re: Status /Orion II
>>>
>>> Thanks for the update.
>>> Hope you're considering it a technical challenge.
>>> Certainly far beyond me.
>>>
>>> Should I post something in the Orion reflector?
>>> Maybe someone else has had this issue.
>>>
>>> Bob, w3idt
>>>
>>> .......
>>> . Robert F. Teitel, W3IDT
>>> .
>>> . w3idt@comcast.net
>>> . w3idt@arrl.net
>>> ........
>>>
>>> On 8/25/2022 1:59 PM, Steve S wrote:
>>>> Hi Bob
>>>> Just a note...
>>>> I replaced final amp caps, no change.
>>>> I've noticed running at higher PS voltage, 14.5V, will make unit unlock
>>>> quickly when xmit SSB,CW or even occasionally even in RX. Lower PS
>>>> voltage, 13V, never seems to unlock.
>>>> I've checked input 1st stage voltage regulators on PLL, and looks ok.
>>>> Almost all of PLL is double regulated so those should be ok. Mystery right
>>>> now why PS voltage influences unlock if PLL Vregs don't change. Wondering
>>>> if PLL control getting messed up somewhere else.
>>>> Ten Tec has info in manual on PLL control details in manual, per band. I'm
>>>> just starting to get into PLL details to see if I can learn more. e.g.
>>>> which VCO is unlocking and why.
>>>> Next Wed or Thurs I'm heading to NC for Shelby hamfest, then continuing to
>>>> FL for relative visit. Should be back in couple weeks.
>>>> 73
>>>> Steve
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
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