New K2 Construction Help

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New K2 Construction Help

Bill Robbins
I bought a partially assembled K2 and am continuing the construction.

I am at p.63, Alignment and Test, Part II.  All is well until I get to
VCO Test.  I get no frequency reading.  The probe is fine and I get 4VDC
at the test point, TP1.

All of the obvious has been done.....Solder bridges, missing parts,
etc.  But, obviously, I am missing something.

Where do I start?

Thanks again to this group.

Bill

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Re: New K2 Construction Help

Don Wilhelm-4
Bill,

The VFO is not oscillating.  Handle the lack of oscillation separately
from any consideration for the PLL side of things - in other words,
first make it oscillate and then if it is not on the right frequency,
that is a different problem to be solved.

Start with T5.  Look at the leads to see if they were adequately
stripped and tinned.  You should see a bit of tinned lead on the
component side and there should be no ring around the leads on the
solder side.  If either of those conditions exist, remove T5 and
rewind/strip/tin.
The other thing to check on T5 is the direction (sense) of both windings
- they must both be the same sense if it is to work.

73,
Don W3FPR

On 12/13/2014 2:02 PM, Bill Robbins wrote:
> I bought a partially assembled K2 and am continuing the construction.
>
> I am at p.63, Alignment and Test, Part II.  All is well until I get to
> VCO Test.  I get no frequency reading.  The probe is fine and I get
> 4VDC at the test point, TP1.
>
> All of the obvious has been done.....Solder bridges, missing parts,
> etc.  But, obviously, I am missing something.

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