[Elecraft] K2 #4913 160m issue?

[Ken Bessler]

----- Original Message ----- 
From: "W3FPR - Don Wilhelm" <w3fpr at earthlink.net>
To: "Ken Bessler" <kg0wx at cox.net>; "Elecraft Main Group" 
<elecraft at mailman.qth.net>
Sent: Wednesday, July 20, 2005 8:15 AM
Subject: RE: [Elecraft] K2 #4913 160m issue?


> Ken,
>
> It is the VCO - not the bandpass filters.  The VCO will stop changing
> frequency when the voltage at the left end of R30 goes much above 7.7 
> volts
> and becomes unstable below 1 volt.
>
> It would appear that you need to re-investigate the entire VCO range
> adjustment and adjust L30 to get everything within range on all bands. 
> See
> the VCO alignment section of the manual (page 61 in the Rev F manual).
>
> If you cannot get 160 meters within range C75 may be at the lower edge of
> its tolerance, a small padder capacitor can often be added across C75 to
> bring things in line.
>
> 73,
> Don W3FPR

Bingo! I actually woke up last night with that idea but I decided
to wait until I heard from the list before messing around.

2000 kc was 8.89v and all my values that I had written down
in the manual were off.

I found I had to make a compromise between 2000 (7.3v) and
3500 (1.83v) when tweaking L30 but all the other bands were
well in range.

The only changes to the rig since I first did the VCO alignment
are the addition of the KAT2, KIO2 and K160RX. Could adding
the 160m module be the culprit? My guess is yes but I could
not find anything in the 160 manual talking about re-aligning the
VCO after installing the module.

Maybe a good candidate for an errata sheet?

Thanks for the help, Don!

Ken
--
  Just my 2¢... 73 es gd dx de Ken KGØWX
        Grid EM17ip, Flying Pigs #-1055
 Proud builder & owner of Elecraft K2 #4913



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