K3 s/n 4365 Need Help

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K3 s/n 4365 Need Help

Bob W7AVK-2
Morning - Completed K3/100 s/n 4365 with ATU and extended receiver
options two weeks ago.  Found would not pass the Synthesize Calibration
test performed during initial power up.   Emailed K3service and .....

Working with Gary have performed the following and/or changed out

      Verified cables and all cards are correctly installed.
      Replacement KREF3 card has been tried
      Replacement KSYN3 card has been tried.
      Verified ADC REF reading is 5.0
      Reading PLL1 voltage get *0 or 7.4 on all bands lower edge

Beside failing the test, the only unusual reading I can find is:  Gary
had suggested when monitoring the PLL1 voltage to give the main Tuning
Knob a twist.  Did this and saw no change.  But recently extended the
test and found the voltage would swing to a reading of about 2 volts
with an oscillation of maybe1 hz back to 0 or 7 when the Frequency was
400-500 Khz above the band.  Increasing the frequency more the PLL1
voltage would lock at around 2 and slowly increase to 4-5 volts.

I'm about used up troubleshooting the box as this is my first K3
experience and so don't know what to expect.  I'm located in Moses Lake,
WA.  Are there any K3 gurus in the Pacific Northwest I could bring my K3
to and ask they check my work and observations to make sure I'm just not
doing something wrong?

Thanks,

73  Bob  W7AVK
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Re: K3 s/n 4365 Need Help

KK7P

>       Replacement KREF3 card has been tried
>  

Did this include a new 49.38 MHz oscillator?  If that is bad, then there
is no reference to which the synth can lock.  Do you have a receiver
that covers 49.38 MHz, or 8.230 MHz?  Or an oscilloscope, freq counter
or other means by which you can verify the 49.38 MHz oscillator is working?

73,

Lyle KK7P
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