[Elecraft] VCO Alignment

[Steve Taylor]

Don -

Thanks for the reply.  I checked as you suggested, T5 turns are okay, I 
looked the capacitors over good and resoldered all, okay.  I do have the 
rework eliminators installed, and I looked them over good, seems okay.  No 
real change.  The strange thing is, when I first power up with the VFO set 
at 4000, I measure about 5.3 volts at R30 and it slowly drifts up.  After 5 
or so minutes it's at 6.3 volts and still climbing.  I think the work I did 
before that I thought allowed me to adjust L30 really was a matter of me 
powering down to spread the windings on T5 and then powering back up.  It's 
a clue, but I don't know what it means.

Steve - WD7M

----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at earthlink.net>
To: "Steve Taylor" <sr.taylor at comcast.net>; <elecraft at mailman.qth.net>
Sent: Thursday, May 18, 2006 7:13 PM
Subject: RE: [Elecraft] VCO Alignment


> Steve,
>
> Check the number of red wire turns on T5 - count the wire as it goes
> threough the center of the core - counting only the outside turns can
> produce a numer that is one turn less than the proper number.  This sounds
> like the sitation that occurs when there is one extra turn on T5.
>
> If you find the turns on T5 are indeed correct, the next most probable 
> area
> to be investigated is the capacitors in the VFO Range Select area.
>
> If you have installed the rework eliminators, be very certain you follow 
> the
> instructions for the rework eliminators carefully - the capacitors for the
> VFO Range select area chnge with these instructions.
>
> 73,
> Don W3FPR
>
> -----Original Message-----
>
> I ordered K2 #5329 in January, and was just able to start on it a few 
> weeks
> ago.  After a short break I'm back at it and this afternoon got to the
> Alignment and Test, Part II.  All was well until I got to VCO Alignment on
> page 61.  At first I was not able to adjust L30 and get the VCO voltage to
> 6.0 volts.  All I could get was 7.99 volts.  After reading the archives, I
> spread the turns on T5, and sure enough, I could get 6.0 volts at R30. 
> But,
> it seems after adjusting, it drifts up slowly.  So, I decided to go 
> through
> the bands and see what I got.  At 3500 Khz, it was a little low, and
> everything 7300 and above is at 7.99 volts.  I've looked the board over
> again and again, and can't see anything wrong.  Whenever I check R30 at 
> 4000
> KHz, it will be off 6.0 volts, when I adjust it back, it continues to 
> drift,
> and everything above 7300 is pegged at 7.99 volts.
>
> I hope someone has some suggestions, because I'm stumped.
>
> Thanks in advance, Steve - WD7M
>
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