K2 - No TX on 10 or 12

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K2 - No TX on 10 or 12

djmd
Good evening all -

Finally got the transmitter all finished up today - power output on all bands except 10 and 12 is looking great. When I hold 'tune' on 10 or 12, it shows power out as .1 and I'm seeing nothing on my meter. Any suggestions on where to start looking?

Thanks in advance...

k8djw
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Re: K2 - No TX on 10 or 12

Don Wilhelm-4
K8DJW,

Build and use the RF Probe that came with your K2.
After it is built, turn the manual to Appendix E and page over to
Transmit Signal Tracing, and move down to the middle of the first column
of page 14 - Transmit Mixer, Buffer, etc.
Instead of following the instructions exactly, use 12 or 10 meters - set
the power at 5 watts and do a TUNE (leave the K2 in TUNE only long
enough to take each measurement, one at a time).
Now determine the first stage in the list that is producing
substantially less the expected RF voltage (since the K2 is not
developing power output, the RF voltages will be greater than the listed
"expected" value).
Once you have found that point, you will know which stage needs
investigation.

With the other bands working, most likely, it is the bandpass filter for
12/10m, and in that case, the RF voltage will drop off sharply at W6.  
If you still have good RF voltage at W6, continue up to the RF Detector
Input.  If the RF voltage only drops off at this last point, your
problem is in the Low PAss Filter for 12/10 meters.

73,
Don W3FPR

djmd wrote:

> Good evening all -
>
> Finally got the transmitter all finished up today - power output on all
> bands except 10 and 12 is looking great. When I hold 'tune' on 10 or 12, it
> shows power out as .1 and I'm seeing nothing on my meter. Any suggestions on
> where to start looking?
>
> Thanks in advance...
>
> k8djw
>  
>  
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