Hi Mike and Don,
Thanks for the replies. We took out the 160 meter board and bypassed it with
clip leads.It has s/n 36XX (trying to remember as Jim took it with him) We also
pulled the KPA100 amp and used the BNC antenna jack to connect to a dummy load
to check power output ... around 10 to 12 watts, then to an antenna to listen
for signals. I will talk with Jim tomorrow and we will start developing a plan
on the bench. Most of my all of my test gear is at my TX home and we are
currently in TN. I have a scope here and a test probe and might have enough
stuff to build the crystal oscillator here ... once again plenty of stuff ...
not in TN. Hi.
Now that I just finished in the TNQP we will start a methodical look at the
front end.
We will keep y'all posted
Thanks es 73,
Mike WA5POK
On Sunday, September 7, 2025 at 04:33:37 PM EDT, W3FPR <[email protected]>
wrote:
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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