[Elecraft] Its not over yet, I've gone back to basic K2 troubleshooting and find i have what seems a massive loss through the variable Crystal filter ?

Clifford Hynds vk2ccj at gmail.com
Tue Jan 29 20:21:32 EST 2013


Still having issues with my K2,

I did align the filters using the Spectrogram software so I believe they
are ok

Well I decided to start from scratch and started RX troubleshooting/signal
tracing  before I go back to TX side want to make sure the RX is 100% and
while the stages up to the input of the crystal filter look ok the output
compared to the manual is extremely low.

I ended up using the RF probe supplied in the kit so all is known.

Also removed the SSB board and fitted the corresponding jumpers at W2 and
W3 and C167

Here is what i am seeing with a 0.14Vrms input to the antenna  I used
10.1Mhz but I tried other bands with similar results.

All voltages up to the input of the variable crystal filter look normal.

Case or collector of Q22 = 2.3Vrms

At W2 = ~ 2Vrms

cathode D30 =0.89Vrms

cathode D31 =0.95Vrms

cathode D32 =0.757Vrms

cathode D33 =0.767Vrms

cathode D34 =0.735Vrms

W3 = 0.080Vrms  the K2 book on Page 11 says it should be about 0.34Vrms , I
am way low compared to that.

I suspect either D34 or T7 ?

Also I don't appear to be able to saturate IF amp it says I should read
approx 0.15Vrms at Pin 8 of U12

Am I on the right track.

Thanks again,
Cliff VK2CCJ


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