k1 testing & alignment

[E Neubauer]

I am at the Alignment and Test - Part I portion of constructing the K1.  All of the tests went GREAT up to the part about Band-Pass Filter Alignment (page 40).  With the antenna connected, I hear only white noise through the headphones.  Adjustment of the slug-tuned inductors does nothing. Connecting and disconnecting my antenna wire doesn't even make a crackle.  I ran the checks in the back of the manual with my RF probe under "Receiver and VFO Signal Tracing" (appendix E pages 5-6).  My input voltage with the battery pack was about 11.5 volts.  Here were the results for the numbered tests under that section:
step 5: .02 V - OKstep 6: .222 V - OKstep 7: .025 V - a bit lowstep 8: 0 volts - fail.
All steps after #8 that failed, as well.
I suppose there is something wrong in the premix band-pass filter, but am not sure where to go from there to narrow the problem.  Again, any help is appreciated.
Ed
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[Don Wilhelm-4]

Ed,

Yes, the most likely place for your problem is the Pre-Mixer bandpass
filter adjustment.
Since you have checked the oscillator outputs with your RF Probe, Use
the RF Probe to monitor the output from the Pre-Mixer - adjust the
Pre-Mixer for maximum RF Voltage at pin 6 of P1 on the filter board.
This part can be done in receive.
If you have a CW receiver that can tune to the Pre-Mixer output
frequency, use it to verify that you are really tuned to the correct
frequency - the correct frequency will be the K1 dial frequency plus
4915 kHz. You may have to bring an antenna wire connected to the
receiver near P1 pin 6 to couple enough signal.

73,
Don W3FPR

E Neubauer wrote:

> I am at the Alignment and Test - Part I portion of constructing the K1.  All of the tests went GREAT up to the part about Band-Pass Filter Alignment (page 40).  With the antenna connected, I hear only white noise through the headphones.  Adjustment of the slug-tuned inductors does nothing. Connecting and disconnecting my antenna wire doesn't even make a crackle.  I ran the checks in the back of the manual with my RF probe under "Receiver and VFO Signal Tracing" (appendix E pages 5-6).  My input voltage with the battery pack was about 11.5 volts.  Here were the results for the numbered tests under that section:
> step 5: .02 V - OKstep 6: .222 V - OKstep 7: .025 V - a bit lowstep 8: 0 volts - fail.
> All steps after #8 that failed, as well.
> I suppose there is something wrong in the premix band-pass filter, but am not sure where to go from there to narrow the problem.  Again, any help is appreciated.
> Ed
> _________________________________________________________________
> Lauren found her dream laptop. Find the PC that’s right for you.
> http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290
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