Talk-O-Phone mainspring replacement

[jboger]

I have a Talk-O-Phone with a busted mainspring (picture attached). The Phonograph Shop has a list of mainsprings by maker/model. According to that list, I should have a mainspring with the following dimensions: ⅞ x 0.023 x 10 : Pear/Pear (units are inches). That seems right, although the height of the broken mainspring is 1 inch, not ⅞ inch (I measured it). I see other mainsprings for sale that are similar, for example this one: ⅞ x 0.022 x 10 Pear/Pear - 5/8A. If I understand correctly, the ⅝ is the diameter of the innermost coil that fits the arbor. Mine measures about 1/16th inch larger than that. So the one for sale has a smaller inner coil than my broken mainspring. That seems OK to me as it would make for a tight fit.

What I'd like to know is, has anyone here replaced a Talk-O-Phone mainspring and, if so, what did he/she use? A second question is, does that ⅝ inch refer to the diameter of the innermost coil? And finally, what do you think, should the one for sale and described above do the job?

Well, any help with this would be most appreciated. And if anyone knows where I can buy a replacement mainspring specifically for a Talk-O-Phone, that would be worth knowing.

John

[JerryVan]

I believe 5/8A means ⅝" arbor diameter. I suppose the guy who sells them might know for sure though.

[jboger]

Jerry: That's great. And that makes good sense. It's easier to measure the arbor diameter than guess it via a sloppy measurement of the inner coil. I'll check tomorrow and let you know. Thanks!

John

[jboger]

The arbor--see photo--is 0.50 inches in diameter, so less than 5/8ths. Still the above-cited mainspring might work given the length of the stud on the side of the arbor. But I shall look some more before I commit to the purchase of any mainspring.

[JerryVan]

If the inner curl of the new spring is a bit sloppy on the arbor, some well placed squeezes with a proper plier can close it up a bit and give a good fit.

[jboger]

I've ordered the mainspring. We'll see.