Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Early B&W and Projection TV

Notices

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 12-13-2009, 06:34 PM
pearsonk pearsonk is offline
VideoKarma Member
 
Join Date: Mar 2006
Posts: 132
RCA 8T-241 fine tuning

The '48 RCA 8T-241 uses a belt for fine tuning, appears to be fabric/leather?
What can I use to replace this belt?
Also need the fine tuning knob, anybody got one?
thanks...........
Reply With Quote
  #2  
Old 12-14-2009, 09:33 PM
jonboy55's Avatar
jonboy55 jonboy55 is offline
VideoKarma Member
 
Join Date: Sep 2008
Posts: 136
For the belt I used to use MCM Electronics part number 42-435.
Reply With Quote
  #3  
Old 12-14-2009, 11:00 PM
pearsonk pearsonk is offline
VideoKarma Member
 
Join Date: Mar 2006
Posts: 132
Thanks but MCM apparently does not have that # anymore.
I was thinking I might make up a fabric belt like the original one but
would rather have something off the shelf - ..............
Reply With Quote
  #4  
Old 12-14-2009, 11:29 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 4,030
How wide is the belt? A common solution in radio circles is to cut a length of O-ring material, place over the pulleys, hold the ends tight, and super-glue them. Sounds tacky, but I have O-ring belts that have held up for years.

Unless the belt is really wide and flat, the round stock works fine. Square stock is available, but it tends to climb out of the pulley more than round.

You want the length so that you have to stretch it a tiny bit to glue the ends. Buy enough stock for two or three tries, in case you don't get the tension right the first time.

An alternative would be to find a flat belt longer than needed, and trim & superglue at the right length.

Phil

Reply With Quote
  #5  
Old 12-14-2009, 11:56 PM
bandersen's Avatar
bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,813
I believe you are referring to this belt. Mine is hard as a rock.
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
Audiokarma
  #6  
Old 12-15-2009, 01:03 AM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 4,030
Clean & lube the mechanism to make sure it turns freely, then try an O-ring belt. It might wander back and forth a bit, but who cares, as long as it grips and doesn't climb out. You can finish the restoration and use the tuner while waiting for the belt of your dreams to show up. Total cost to experiment: about 25 cents.

Guys who restore Zenith TransOceanic radios claim you can soften hardened rubber suction cups (on the WaveMagnet) by soaking in Armor-All for a long time, like a week or two. No idea what your belt's made of, so who knows whether it would work. Maybe you'd end up with a rock-hard belt that's really shiny. On the other hand, what have you got to lose?

Just some ideas . . .

Phil
Reply With Quote
  #7  
Old 12-15-2009, 08:47 AM
pearsonk pearsonk is offline
VideoKarma Member
 
Join Date: Mar 2006
Posts: 132
Thanks all, bandersen's pic is exactly it............ its 1/4" wide and hard as a
rock. The tensioner makes use of a all rubber belt not practical. Original was
layered fabric, not sure if it was rubberised or not - construction probably similiar to auto v-belt, but flat.
I hoped someone had solved this problem already, I'm still trying to figure out
an off-shelf solution.
thanks again............
Reply With Quote
  #8  
Old 12-15-2009, 10:47 AM
old_coot88 old_coot88 is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 2,646
I've never done it, but how 'bout a piece of flat shoelace, with the splice cut on a bias and stitched with sewing thread? Then "rubberize" the finished belt with something very pliable like thinned contact cement(?). Just an idea. Bill(oc)
Reply With Quote
  #9  
Old 12-15-2009, 03:48 PM
leadlike's Avatar
leadlike leadlike is offline
VideoKarma Member
 
Join Date: Apr 2008
Location: Lancaster, Pa
Posts: 956
The belt on my RCA t-120 is the same. It looks to be all leather, and still in decent shape, although it does slip a bit. If you look at later production models, they add a fine tuning knob above the tuner that does away with that belt mechanism, meaning it must not have worked so great when new.
Reply With Quote
  #10  
Old 12-16-2009, 01:07 PM
pearsonk pearsonk is offline
VideoKarma Member
 
Join Date: Mar 2006
Posts: 132
'old coot88' is apparently on target, but instead of shoe laces, I used bias tape from a fabric shop, 1/4" wide:: cut to length, contact cement into loop, when dry, contact cement inside loop & let dry - provides good grip & works well so far.
Also tried metal dial cord, 3 loopes on each pulley, works great. Existing tensioner used. Fabric dial cord will probably work as well.
problem solved
thanks for input...........
Reply With Quote
Audiokarma
  #11  
Old 12-30-2009, 04:46 PM
bandersen's Avatar
bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,813
Quote:
Originally Posted by Phil Nelson View Post
...
Guys who restore Zenith TransOceanic radios claim you can soften hardened rubber suction cups (on the WaveMagnet) by soaking in Armor-All for a long time, like a week or two. No idea what your belt's made of, so who knows whether it would work. Maybe you'd end up with a rock-hard belt that's really shiny. On the other hand, what have you got to lose?

Just some ideas . . .

Phil
LOL - I had forgotten all about this! Mine has been soaking for two weeks now

It actually works fine now Seems to be made of several layers of fabric impregnated with rubber.

__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery

Last edited by bandersen; 12-30-2009 at 06:02 PM.
Reply With Quote
  #12  
Old 12-30-2009, 11:48 PM
cbenham's Avatar
cbenham cbenham is offline
VideoKarma Member
 
Join Date: May 2006
Posts: 471
Anybody know if Amor-all will rejuvinate the rubber idler wheel for the record player in my old RCA TV console?
Reply With Quote
  #13  
Old 12-31-2009, 12:05 PM
kx250rider's Avatar
kx250rider kx250rider is offline
REAL TVs have TUBES!
 
Join Date: Oct 2005
Location: Los Angeles & Dallas
Posts: 3,239
I've used two flat VCR belts ontop of eachother for thickness, and also in a pinch, a square or round belt will work. I have several new old stock RCA fabric belts, but they're just as dried & hard as yours probably is/was.

Charles
__________________
Collecting & restoring TVs in Los Angeles since age 10
Reply With Quote
  #14  
Old 12-31-2009, 12:32 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 4,030
Quote:
Originally Posted by cbenham View Post
Anybody know if Amor-all will rejuvinate the rubber idler wheel for the record player in my old RCA TV console?
There is a product called "Rubber Renue" designed for rejuvenating hard/glazed rubber things like idler wheels or rubber platens. Search with your favorite engine and you'll find suppliers, including Antique Electronic Supply. Maybe this would work on belts, too. I didn't think of it until you mentioned an idler wheel.

Phil
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:50 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.