Radio Overhaul - Repair page 1

I'll start with the easy peasy mechanical stuff first. I'll address the slipping manual tuning.

The manual tuning has a little clutch assembly. There's basically a flywheel, if you will, friction disc and a little pressure plate.

Here's the parts stack up.

The friction disc is, or was, a piece of serrated rubber that turned hard due to age. This needs to be replaced.

First, will be to estimate its original hardness. This is a Shore A gauge and so we can assume it originally was under 70 shore A.

I have two sheets of EPDM rubber to choose from; 50 A or 60 A rubber. You can buy these at McMaster. I choose the 60 A rubber sheet that came in under the rating a bit.

The original disc measures 0.049"

The replacement is ~0.059" There is an adjustment on the fork for the little pressure plate so a slightly thicker piece of friction material will work.

Since the replacement sheet was smooth, I used a very course sandpaper to scratch radial lines on one side of the friction and roughed up the pressure plate with finer sandpaper. I also glued the friction disc to the flywheel so there's only one side to slip on.

Cleaned and greased (white lithium) the manual tuning knob and reinstalled.

Adjust the tension on the pressure plate and it works like new, no more slipping manual tuning knob and the preset buttons disengage the clutch fully when pressed. Cross that off the list.