RadioBanter - View Single Post - GE Super Radio III Tuner Re-Thread?

[email protected] · August 23rd 06, 06:18 AM posted to rec.radio.shortwave

wrote:
Hi -

Does anyone have any pictures or diagrams of how to re-thread the GE
Super Radio III vernier? The Service Manual doesn't discuss it.

Thanks for everyone's advice. I'm just posting this here for the
archives.

The following is a description of how to re-thread a GE Superadio III
vernier tuner as the Service Manual doesn't discuss it.

Background:

I knocked my tuning wheel loose while fixing my radio. I had a
problem last year at this time where after a half hour of use, my
then ~9 year old radio would slowly tune itself across the band
like an invisible hand was turning the dial.

I tried to diagnose it, but the problem went away and didn't return
after I hit the tuning pot at R2 with freeze spray.

I was OK for about a year, until it re-occurred this summer. I hit
R2 with the freeze spray again, and the problem would only go away
momentarily. I looked at the bottom of the circuit board and it was
quite dirty with flux. I theorized that in humid weather the rosin
was affecting the circuit. I cleaned the PCB around R2, accidentally
knocking off the tuning wheel. Now the problem seems fixed but I
couldn't get everything back together as I didn't take notes, never
intending to remove the tuning wheel and thread.

Summary:

The small loop on the string attaches to the spring hook on the tuning
wheel, then around spools 6,1,2,3, loops capstan twice,4,5 and then
from spool 5 to the big hook on the wheel:

(ASCII art facing front of radio)
1 ------------------ Vernier ----------------------------- 2
| 5 |
6 ------------- Spring Hook \ 3
Wheel "D" slot at R2 \ |
Big Hook \ Two Capstan Loops
\ |
-----------4

Details:

Equipment Needed -

1) Locking forceps or very small needle nose pliers to grip thread.
2) Small hand mirror to view underside of tuning wheel where thread
hooks to.

Procedure -

A) Place vernier at upper limit of band (108 MHz FM / 1700 KHz AM).
B) Tune pot R2 to upper limit of band
C) Place small string loop over tuning wheel spring hook.
D) Attach wheel so hooks face back of radio.
E) Thread string from wheel to spool 6 to spool 1 to vernier.
F) Slowly turn wheel clockwise, spooling string on wheel until vernier
is at lower end of band (88 MHz FM / 530 KHz AM).
G) Thread string from vernier to spools 2,3, twice around capstan, 4,5,
then through wheel slot. Place big loop around big hook using forceps
or very small needle nose pliers to grip end of loop, a mirror, and
then snagging loop on the hook.

Tips -

I broke the string at the knot of the big loop because I didn't
have locking forceps or a very small needle nose pliers. I recovered
by making a bowline knot in broken end, and then with strong thread,
another bowline loop chained to the new big loop I just made which I
then attached to the big hook.

Dan Nygren

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