[Elecraft] Need Help with XG1
Pete Smith
n4zr at contesting.com
Thu Jan 29 06:14:45 EST 2009
Thanks Don. Unfortunately, all those variables test OK. I've gotta fix my
old scope!
I think that voltage must be an indication that the transistor oscillator
is at least drawing the right amount of current through R9. I'm going back
to recheck all my work on the default output attenuator. Must be something
there, particularly since the additional stage of attenuation when I switch
in the 1 Uv position seems to be working properly.
73, Pete
At 02:30 PM 1/28/2009, Don wrote:
>Pete,
>
>Do you have the proper voltage on Q1? Check for 1.22 volts at the cathode
>of U2. Also check the value of R3 and R3 with your ohmmeter.
>
>It sounds like you have replaced everything important, but if you had
>enough RF to fry the resistors, you may have damaged the switch contacts
>at the same time. You should be able to determine the resistance through
>the switch with your ohmmeter. Do that for both poles, and both switch
>positions.
>
>73,
>Don W3FPR
>
>Pete Smith wrote:
>>Thanks for the idea - I removed both D1 and D2 from the circuit - no
>>improvement. The signal is quite audible (in the 50 uv switch position,
>>and barely audible in the 1 uV position, but doesn't move an S-meter that
>>was formerly tested with it and registered S9.
>>
>>Anyone else? I know that if I had a scope I could measure the p-p
>>voltage coming out of the oscillator, but I don't.
>>
>>73, Pete N4ZR
>>
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