[morzh]

About 6 years ago I restored Westinghouse WR-212 and  bought the tuning drive belt from Adams mfr.
This was the set I gave to my dad.
This week I came to FL to my parents (I do it about every other year), and decided to try the radio, which was just fine 2 years ago.
I couldn't tune anything and then realized the dial wasn't moving.

First I thought it was frozen. Used anyfhing from theflon lube to PB and WD40. Nothing helped.

Then I took the belt off and this us what I saw:

   

The belt has hardened after long disuse and froze the way it was stretched.

I tried to soften it in hot water but it just came unglued and didn't become much more pliable.
Good thing the local Ace hardware had one sole O-ring of exact same size, this took care of the issue.

So. If you have radios on display that use neopren belts, abd which you rarely use, make sure the belt is exercised. Or it might become unusable.

[Phlogiston]

You are correct.

Those black hardware-store O-rings are worse. They will harden and crack in about a year if stretched at all.

P.S. You might want to consider - - http://philcoradio.com/phorum/showthread...#pid149678

[Eliot Ness]

I restored a Sparton console for someone a few years ago and had to replace the black O-ring after less than a year due to cracking. All my Zenith's that now need belts were using black O-rings. I have some belt material from Alan Jespersen that is square..... cut and glue..... and it looks pretty sturdy.

My friend Terry accidentally made some dial belt material by squeegeeing some Plasti Dip over a sheet of some cloth material. Cut into thin strips these are more like the original or JFD flat dial belts and he claims they work great, but they need to be cut and glued also and he puts a stitch or two at the joint for added strength. I have a few strips of his material somewhere but haven't tried it yet.

I bought enough of Adams belts for all my Zenith's and Fairbanks Morse console so hopefully I'll get at least 5-10 years out of them, if not I'll be doing some cut-n-glue with dial material from Alan, Mark Oppat, or my buddy Terry.

[Kestas]

I have a stash of garter springs for this purpose. No longevity issues in service.

[EdHolland]

McMaster Carr have polyurethane round section belts in a wide range of thickness and overall size:

https://www.mcmaster.com/round-belts

There seem to be other sources too.

I like the garter spring idea.