[Johnson] Ranger VFO question.

[Jim Brannigan]

Dee,
Thank you for your response.
I spent several hours tracing the cause of the arcing.  All clues pointed to
a factory defect in the "make before break" wafer on the switch.  Since the
switch did not show signs of arcing until I modified the Ranger, I suspected
my work and was ready to go all over it again.
I don't have an extension for my Dremel and even with one it would be hairy
to get in there.
Thanks for the time saving, I can proceed with the rest of the restoration.

On power supplies, I solid state all of them The only problem encountered
was with a Collins S-line.  The LV was a bit too high.  A resistor in the LV
section brought it down to a reasonable level.

73,
Jim

> Morning All
> Had to make a few comments on Ranger restorations. As to the "arcing" of
the
> VFO sw., that is common on a lot of Rangers & can fry the 470 ohm resistor
> inside the VFO can. What to do? The best approach & the one I do on every
> restoration is with the Dremmel tool (w/ flex shaft addendum) & a
> carborundum blade wheel, carefully grind both contacts of opposing edges
on
> the switch off so that the rotating contact will not "short" when rotating
> from 80m to 40m. If you are not brave enuf (grin) to try that, REMEMBER to
> move the crystal / VFO select to "crystal" position before changing those
> bands. Problem only happens when going from 80m to 40m. No worry on other
> band changes. Seems Johnson bought many VFO switches with that err
problem!
> How do you know you have one of those switches? One time you will get that
> aroma of burned resistor as the smoke comes thru the freq adj. holes of
VFO
> can. And then no VFO operation @ all.
>
> Comment on SS the power supply: I solid state most restorations. I have no
> problem afterward. Reason is the HV NEVER goes over 600v (+ a little). If
> one makes the mistake of placing a filter cap on the INPUT SIDE of the
> filter choke, B+ will go 800v ++! Don't do that! Choke input only. By SS
the
> LV, voltage is typically 380v - 400v. These are no load voltages. Voltage
> drops under load somewhat. I find by SS'ing, the no filament current helps
> on the overall heat condition on old transformer (the lo voltage tf). Also
> under load, the net 380v of lo voltage works better for my 300v SS
regulator
> I use to feed the modulator screens & clamper tube. I eliminate the 50w
> "chassis heater" altogether & obtain my modulator idle current from off
the
> minus supply off the CW time delay deck (also regulated & a 10K 10 turn
pot
> added). However, these SS devices are "plug in " devices. So the tube
socks
> are factory wired. One other thing needs to be done on all Rangers: The
> problem w/ arcing on switches. Almost all Rangers have hi grade function
> switches. If cleaned & contacts are in good shape / adjusted properly, I
> have never had a problem w/ that switch. The problem comes on the METER
> SWITCH. That dude has HV on it all the time. Best solution is replacing it
> w/ Centralab 2003. Yep, its costly if you have go out & buy one new from a
> supplier ($35. maybe). Look for one @ hamfest. Make sure its porcelain
> before putting your money down. Next best thing to do is thoroughly clean
> the meter switch & then CAREFULLY paint the wafer front & back w/ HV
enamel,
> the kind they used to used on TV HV circuits & use in motor shops today on
> electric motor rebuilding. I have never had a problem yet doing that. The
> problem on that switch is where HV contacts are too near the grounded
frame
> of that switch. That's where special care has to be taken.
>
> These are just a few suggestions I hope you Ranger Afectioneros might find
> helpful (essential?)
>
> Very Warm Regards
> Dee, W4PNT