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Tuning cap grommet thickness for 16X? - Printable Version

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Tuning cap grommet thickness for 16X? - k9uw - 09-19-2015

I'm close to the end of a 16X (Code 125) restoration and have run into a question.

The grommets supporting the tuning capacitor were dried out and I ordered replacements (GS-m grommets, seen at http://www.renovatedradios.com/parts.html near the bottom of the page) from Renovated Radios.  The replacements are like the original in that they feature a collar of rubber that fits the hole in the chassis.  The raised collars fit into the chassis opening from above and below, using two grommets at each of the tuner's three support points.

The new grommets are not working out, however, and they seem to be too thin.  The old grommets surrounded a metal sleeve that is 1/2" long - the same thickness as a pair of the GS-m grommets.  When I pass the mounting screws through the grommets and tighten them, the metal sleeve comes into contact with the tuning capacitor mounting foot at one end and the head of the screw at the other.  It cannot be tightened any further, yet the grommet has no weight on it and the capacitor wobbles in place.  It would seem that additional thickness is needed.

I improvised by reversing the grommets so the collars are facing away from the chassis to make them a bit thicker.  It was still necessary to add more material, so I employed a 1/16" thick rubber washer above and below the chassis to create the tightness I assumed was necessary.  

The tuning capacitor no longer flops around.  It moves a bit if I wiggle it, but the grommets are now slightly deformed after tightening the mounting screw all the way.  

I shared this information with the owner of Renovated Radios and he is eager to determine the correct thickness of his grommets for the 16X so he can produce a product that fits and does the job without modifications.  The old grommets he used as a pattern came from a radio that did not have the metal sleeve inside the grommets, and that obviously impacts what will and will not work.

My questions, then are:  What have you all used for tuning capacitor mounts?   How thick should they be?  Have I made correct assumptions about how "tight" that tuning capacitor should be?

I know that many restorers use hardware store rubber donut grommets, but I'd like to provide Renovated Radios with an accurate measurement of what he needs to produce for the 16X, and possibly other sets.  

As always,  thank you for your replies and help.  Ron, your advice (months ago) about the correct mount for the 16X's tuning dial enabled me to find the right part!

RE: Tuning cap grommet thickness for 16X? - codefox1 - 09-20-2015

Use whatever you have, need a little more room, split another one and add to stack. Easier than reaming out the hole in the cabinet, or am I missing something?