[Johnson] Kit wiring instructions for Johnson Valiant

[Jerry K]

Can't argue with that. Glenn. Haven't done any scientific experiments, 
but I have overhauled six over the past several years. I put the 
resistor outside on all of them, and have had excellent VFO stability 
from all six. Maybe I was just lucky, or maybe I was using more warmup 
time or something.
Jerry W5KP

On 1/19/2012 12:01 PM, Glen Zook wrote:
> There have been a number of experiments concerning the placement of 
> this resistor.  Most have found that putting it outside of the VFO 
> compartment actually affects the stability of the VFO in a negative 
> manner.  The VFO temperature compensating capacitors were chosen to 
> include the effect of the heating caused by the 18K ohm resistor. 
>  When the resistor is put outside of the compartment it takes longer, 
> in some situations never, for the temperature to reach the conditions 
> at which the compensation capacitors were calibrated.
>
> Of course, the choice of where to locate this resistor can only be 
> made by the person doing the modification.  However, the previous 
> experience of others should be considered.
> Glen, K9STH
>
> Website: http://k9sth.com
> ------------------------------------------------------------------------
> *From:* Jerry K <w5kp at hughes.net>
> *To:* johnson at mailman.qth.net
> *Sent:* Thursday, January 19, 2012 11:07 AM
> *Subject:* Re: [Johnson] Kit wiring instructions for Johnson Valiant
>
> While you're in there, don't forget to replace the famous 18K
> "Chernobyl" dropping resistor with a 5 or 10 watt power resistor mounted
> OUTSIDE the VFO box. Mouser sells nice compact power resistors for
> replacements.
>
> Stu is right about the front panel, so unless you just HAVE to pull the
> front panel for other reasons, on most of the half dozen or so I've
> overhauled I've been able to get away with just removing the side
> plate--a little tougher access and requires some extra finger gymnastics
> during component replacements, but not all that bad, and far less
> dangerous to the one irreplaceable part on the Ranger--the ultra-fragile
> and brittle "flex" (ha!) insulated tuning shaft coupler behind the front
> dial. Also, mount a couple of fuses inside the rear wall of the chassis
> (Radio Shack sells a little plastic 3AG dual-fuse mount that fits
> nicely) and replace that Rube Goldberg fused power plug and cord with a
> standard three-wire grounded plug and cord. Easy to do while you have
> the little beast upside down on the bench during recapping.
>
> I believe the little Ranger is the best small boatanchor ever built...
> Have fun!
> 73 Jerry W5KP
>
>