[Johnson] [Boatanchors] Johnson Ranger VFO Access Question

[Bill Cromwell]

On 12/27/2013 07:14 PM, w7fe wrote:
> Oh boy, Scott -- you have picked a rather tedious but not impossible 
> project.  I just got my Ranger back together last week so it's fresh 
> in my mind.  It is pretty obvious what needs to be done, but one 
> somewhat major caution follows:
>
> Yes, the front panel must be removed to get full access the interior 
> of the VFO. However, the following is important prior to panel 
> removal:  There is a hole in the chassis through which a small, long 
> shaft, flat-blade screwdriver can be passed to access the set screws 
> on the flexible coupling which connects the front panel reduction 
> drive to the VFO capacitor. Be sure to get those properly loosened 
> (the ones which contact the shaft of the reduction drive) before you 
> remove the panel.  Over the years the heat in the VFO box will have 
> taken its toll on the micarta material in the coupling, making it very 
> brittle. Use extreme care when disengaging the reduction drive from 
> the coupling-- even a seemingly minor sideload may cause that thin 
> "flexible" phenolic/micarta portion of the coupling to break.  Loosen 
> the coupling nut from the panel after all other stuff is loose and 
> keep it steady and in place with one hand while removing the panel 
> with the other. I found it most advantageous to let the panel hang 
> over the front edge of my bench and work it off gently while holding 
> the reduction drive steady.
>
> OK, so you did all that but still broke the coupling.  It happens. 
> Save the pieces!  A replacement coupling is hard to find because one 
> end  accepts a 1/4" shaft (the reduction drive) and the other end a 
> 3/16" shaft (the capacitor). Have no fear -- it is relatively easy to 
> repair.  JB weld is your friend, or some folks have used RTV to effect 
> a repair. You'll see what is necessary when you have the pieces in 
> your hand.
>
> While you have the VFO apart, you might as well remove the 18K series 
> resistor for the VR tube and put it in a convenient place under the 
> chassis. Most of the Ranger gurus recommend this, although I did see a 
> dissenting article which argued that keeping it nice and hot in that 
> compartment added to the (eventual) VFO stability. Whatever is your 
> pleasure, I guess, on this one.
>
> Reassembly procedure will be obvious, keeping in mind the logical 
> order of assembly so that you have access to the two  screws at the 
> front of the VFO box before you put the panel back on. Yes, getting at 
> those flex coupling set screws is a genuine PITA -- a strong light 
> source aimed at the front hole will help you to see the screws though 
> the bottom access hole. Also, I found that the easiest way to get the 
> phenolic calibration cap extenders on place was to remove the top 
> c-clips, set all 5 in place and jockey them into the holes with an awl 
> or dental pick as you put the cover in place, then reinstall the c-clips.
>
> You may decide that the preceding is a lot of unnecessary work and 
> that enough access will be afforded by removing just the side panel. 
> Wouldn't blame you a bit if you choose that option. My unit was 
> complete with died mud and some corrosion, so I wanted to get at the 
> whole interior of the VFO for cleaning.
>
> Hopefully others will chime in with additional/alternate ideas and 
> experiences. Enjoy!
>
> 73 de Stu, W7FE
>
Thank you Stu,

Scot also posted to another list and I replied there with much of the 
same info about that coupling. I didn't know about how to repair it if 
the worst happens. Other people on this list might want that info and 
now they have it thanks to you.

73,

Bill  KU8H