[Bill Schmidt]

I am just starting on a model 90 restoration and I've noticed that the tuning dial only works when the tuning capacitor is turned fully clockwise (low end of the dial). When the plates mesh a quarter of the way the dial slips and will not tune. I have cleaned and oiled the shaft to no avail. Any thoughts on how to correct this problem?

[morzh]

I have the same problem. In 90 and 70. Not sure what to do about it.
Moving the diall a bit forward helps but then the dial itself rubs against the escutcheon.
You could try for starters clean the grooved wheel from any grease and grime that could've gotten into it, but no guaranrtees there.
It works in my 90 but I still have a zone where the slippage is pronounced and it takes several turns to move the dial past it.

I wonder if taking small pliers andcompressing the groove on the disk would help.
Or using some violine rosin powder maybe to increase traction.

[klondike98]

I've seen vintage radio repair kits that included containers of cement, dope, lubricant and a rosin for increasing the friction on the dial string. I'd think violin rosin would work.

[morzh]

Rosin is rosin. I played violine while a kid and I used its rosin for my soldering needs more than for the bow. It is a regular rosin. If rosin works it will work whether violine or technical.