Cliff,
When looking at the RF voltage after the IF filter, tune the K2 slowly
while looking for the peak RF voltage at U12 pin 4.
You will not be able to see the IF amplifier saturation with diodes D40
and D41 in place - that information is prior to the introduction of
those diodes.
T7 should be with the green winding closest to the crystal filter, the
red winding adjacent to pins 4 and 5 of U12.
Turn off the AGC (press PRE and REV buttons together) and see if the
audio level comes up.
You should have more RF voltage at U12 pin 8 than you do at U12 pin 4.
73,
Don W3FPR
On 1/29/2013 8:21 PM, Clifford Hynds wrote:
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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