K-2 VCO allign - help

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K-2 VCO allign - help

Smythe Family
All has gone splendid thus far in the K2 construction.  That is, till now.
I am in alignment and test,

Part II.  VCO alignment:

 

I have the correct slug tuned inductor installed at L30.  When I connect my
DMM to R30 (Lt side) and ground, VFO set to 4000 kHz, I get a reading of
7.95 volts.  Turning L30 (as you may have guessed) is doing nothing.  Am I
doomed to checking solders my entire Sunday (which is still more fun than
watching the Lions lose) or is there a usual suspect or problem spot?

 

Thanks

Dohn - N8EWY

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RE: K-2 VCO allign - help

Don Wilhelm-3
Dohn,

You may or may not have to spend all afternoon checking the soldering, but I
can tell you that a solder splash on the thermistor board is one of the most
common problems with the PLL.

As a quick check, measure the voltage at U6 pin 5 - it should be 4 volts
(+/- 10%) - if it is not, then for sure you have a problem with the
thermistor board.

You can get a view of the back of the thermistor board by removing the front
panel and control board.  Look carefully at the junction of RE and RF - it
is easy to create a solder bridge to ground there.

> -----Original Message-----
>
> All has gone splendid thus far in the K2 construction.  That is, till now.
> I am in alignment and test,
>
> Part II.  VCO alignment:
>
> I have the correct slug tuned inductor installed at L30.  When I
> connect my
> DMM to R30 (Lt side) and ground, VFO set to 4000 kHz, I get a reading of
> 7.95 volts.  Turning L30 (as you may have guessed) is doing nothing.  Am I
> doomed to checking solders my entire Sunday (which is still more fun than
> watching the Lions lose) or is there a usual suspect or problem spot?
>
> Thanks
>
> Dohn - N8EWY
>

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