Addendum to earlier post
As a side note,
there is a quick and easy way to convert one of these radios to run on reverse polarity. I used to do it with Buick (negative ground) radios for use in Chrysler product (positive ground) cars. All you do is swap the transformer's two HV secondary leads (leaving the center tap alone). And presto, the radio runs fine on reverse supply polarity.
Doggone, I never saw one before where the vibrator itself can be reversed. L'arn sumpthin new every day.
