[Elecraft] A broken K3

[Martin Sole]

Hi David,

I had a couple of failures this past year on my early K3 s/n 298. It's 
been updated with new synths and a new KRX3A plus it was updated some 
years ago before I got it and has most of the factory mods, though not 
the gold pins. If you search the archive here on my callsign you can see 
what I posted. Briefly I had first a loss of TX and some months later a 
loss of RX and TX.

Both faults were traced to 0.1uF decoupling capacitors on the K3REF 
board going leaky and puling bias voltages down such that they would not 
switch the various circuits/signals.  In the first case it caused loss 
of the TX bias voltage so the diode switching was not working. In the 
second case it was causing loss of second L.O. injection which of course 
made for a rather quiet receiver as well as no transmit.

Good luck, for sure you can fix it or get it fixed.

73
Martin, HS0ZED






On 25/03/2020 21:49, David Olean wrote:
> Hello Jack, I have responded to Keith and am following his directions. 
> He had lots of good info for me to try, and I am grateful for that.
>
> Dave, K1WHS
>
> On 3/25/2020 5:48 AM, Jack Brindle wrote:
>> David;
>>
>> Go back and re-read the message from Keith Trinity. Keith is one of 
>> the guys down in Watsonville and knows more about the K3 than just 
>> about anyone.
>>
>> To put it another way, you were indeed contacted by Customer Support.
>>
>> 73!
>> Jack, W6FB
>>
>>
>>> On Mar 24, 2020, at 7:46 PM, David Olean <K1WHS at metrocast.net> wrote:
>>>
>>> I swapped out the non working synthesizer with a good one I had 
>>> removed for an upgrade. The new one did not work either, so it is 
>>> something else. I tried calibrating both synthesizers and received 
>>> an error message ERROR 00044 on both of them.  I have been trying to 
>>> contact Elecraft support, but have no joy there yet.
>>>
>>> I guess I need to study the schematics some more. I must be missing 
>>> a voltage somewhere. I tried re seating the connectors on many of 
>>> the boards including the front panel. No luck there either, but I 
>>> will try again tomorrow and use some DE-OXIT.
>>>
>>> 73
>>>
>>> Dave K1WHS
>>>
>>> On 3/25/2020 2:14 AM, Wilson Lamb wrote:
>>>> Why wouldn't you change  the synth?
>>>> I wouldn't even think of troubleshooting such a complicated, but 
>>>> free, board!
>>>> A bad one will obviously shut down both RX and TX!
>>>> WL
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