[Elecraft] K2 Receiver dead

[W3FPR]

Mike,

What is the serial number of that K2?  If below 100, it is a Field Test 
model and is slightly different that those above that SN.

I would not recommending "shotgunning" the problem, there is a 
methodical way to go about it which will lead to the problem area 
without guesswork.

The best way to troubleshoot a dead receive problem with the K2 is first 
to remove the KPA100 completely, and then test the base K2 from the 
lower panel BNC connector.
See the Troubleshooting section of the K2 manual (Appendix E). Since you 
do not have a signal generator, you could build up the crystal 
oscillator shown on page 9 of the Appendix.  If you do not have a 
'scope, you can use the RF probe also shown on page 9.  It does not have 
to be 'pretty' for this job, pushing the component leads though 
cardboard and soldering them together will work fine for the frequencies 
involved here.

The troubleshooting steps begin on the right column of page 10 and 
continue thru the left column of page 12.  With the proper input level,  
you are looking to find the first stage that that has lower than 
expected output.
Once you locate that stage, let me know and I can help you with 
component by component checks to solve the problem.  Dave Van Wallingan 
W8FGU can also assist since he is the current /major repair person for 
the K2 and other legacy gear that I used to repair.

73,
Don W3FPR


On 9/7/2025 1:07 PM, Mike Furrey via Elecraft wrote:
> At a hamfest a week ago there were two k2s for sale from an estate. I bought one and a friend (not on here yet) bought the other. His receiver is dead. The transmitter has full output (110 watts) on all bands. The receiver ... AF gain works, side tone works, filters work, and RF gain works. This can be heard in the change of the pitch/volume of the noise emitted.
> ATTN and Preamp do not work/function. We see no codes. We made a cursory disassembly and unseated and reseated all the boards. It has the 160 meter option in, and we bypassed it.  Unfortunately I sold my old signal generator at the hamfest in anticipation of getting a more up-to-date unit. Hmmm mabe use my old Model 59 GDO as a generator. We are thinking relay ... haven't yet gone into it that far. One thing that puzzles me is the RF gain control (R4). Where is it in the circuit? I see it connected to J1. I see it coming off of P1 and that is it where it ends!!?? I see R5, R6, R7, etc but I can't find where R4 connects? I am thinking a relay somewhere in there? loose jumper or plug I have overlooked? Maybe someone can throw me a bone as to a hint as to where to look for the missing RF to the receiver.
> Many Thanks, Mike WA5POK
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