[Elecraft] A broken K3

[David Olean]

You are right, Bill,

I have three K3s and the two oldest ones had old synths. I upgraded one 
of them and kept one AS-IS so I could compare them. I do have two old 
synthesizers. If worse comes to worse, I can plug one in and then I 
think I need to do some form of synthesizer calibration . It has been so 
long, I forgot! I did want to see if I could fix this one.

Dave K1WHS

On 3/24/2020 5:17 PM, Bill Steffey NY9H wrote:
> from looking at your pictures on QRZ  it looks like you also have a 
> k3...  I would imagine you upgraded the synth boards ????
>
> yes??
>
>
>
> bill
>
> On 3/24/2020 12:57 PM, David Olean wrote:
>> For all you tech gurus,
>>
>> I am trying to fix an old K3 that belongs to my brother. He has 
>> serious medical issues and I was hoping to fix his K3 so he can use 
>> it and be on the air in between chemo treatments.  He is very 
>> isolated and a working ham rig would be a big help to him. I am not 
>> having much luck with tech support with all the virus concerns and 
>> work disruptions. Here is what is happening in his K3 SN: 378
>>
>> No receive or transmit. I hear no band noise, just a bit of hiss with 
>> the volume turned to max. He was in the middle of a QSO and it just 
>> died. When you transmit, it acts like it is transmitting but there is 
>> no output. The digital readout indicates a frequency and it changes 
>> as you turn the big knob, but the K3 hears nothing and transmits 
>> nothing. If you change bands the rig changes bands and all looks OK 
>> as to frequency readout etc. I hear all the relays clicking, but no 
>> RX or TX anywhere.
>>
>> I see a 8.23 MHz signal at the RXIF  cable on the RF board (J-81) 
>> from the KREF board. It is about  100 mv p to p.
>>
>> I do not see any signal on the TXIF  cable going to the RF board 
>> (J-65) from KREF board.
>>
>> I checked at Pin 2 on P73 (The synthesizer) for any RF output from 
>> the VCO and I see nothing except some suspicious DC fluctuations that 
>> amounts to a jump of maybe 100 mv. It looks random and not normal.  I 
>> should see several volts of RF here I think!
>>
>> I do see the 49.380 MHz signal in the KREF board. (J1 & J2) That part 
>> is working normally.
>>
>> This is telling me that I have a synthesizer problem. Are there 
>> things to check on the Synth board?  Is there any typical failure 
>> mode that has shown up?  Are the boards repaired, or must I buy a new 
>> synthesizer board?  This is an original synthesizer board, not a new 
>> design K3S board.
>>
>> I have been waiting for days to get any tech support response.
>>
>> Any help would be appreciated.
>>
>> 73
>>
>> Dave K1WHS
>>
>>
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