[Johnson] Rebuilding Johnson Navigator ???

[C E]

Hello Mike:
Just a few notes here. I will also be doing a refurb,
mod of my Navigator once I get a "round tuit."

The VFO is identical to the other famous EFJ xmtrs
from the Ranger, 500, Valiant, et al. As you can
probably guess, that vaunted 18K resistor has been a
source of trouble (like others have said in this
thread). My solution would be to get that resistor and
clip it to expose just the leads. Get a pair of wires
and hook it up the leads as well as bringing it down
through the VFO and out to the bottom of the chassis.
Substitute (like what some had said) with a higher
power version of the 18k resistor. In my case, I
mounted it to a terminal strip and used a 20k 5 watt
unit (which worked fine). I bolted the terminal strip
to the bottom so it had an anchoring point on an
exisiting piece of hardware in the Ranger. Draws the
heat out of the VFO. Also, change out or check the
6Au6 and OA2 tubes while you're at it. Inspect the
insulated shaft coupler to see if there are any
cracks. This is another thing  you have to watch out
in these VFO's of this nature. FWIW.

Cal. 
--- Michael Crestohl <W1RC at Verizon.net> wrote:

> Good morning all:
> 
> I am completely rejuvenating my beloved NAVIGATOR.  
> Presently the VFO
> covers have been removed to because I need to 
> loosen up the internal
> bandswitch which has become stiff and difficult to
> operate.  While I am
> inside the VFO I am wondering if any component
> modifications,
> substitutions or replacements should be made in
> order to improve vfo
> stability.  I am not a purist and have no
> compunctions about performing
> modifications to the circuitry with the proviso that
> they could be reversed at
> some point (not by me) in order to retain
> "originality".
> 
> I welcome any suggestions from thus august group
> regarding this project.
> 
> 73,
> 
> Michael Crestohl,
> W1RC
> 
> 
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