Re: 1947 Radio

Posted by Tim Cole On 2013/12/5 15:25:40

If you want to screw around with the radio then why not first acquire an understanding of what this information means and is supposed to be used for?

Radio people will tell you those old Philco's are good radios.

There is a voltage chart that can be used to diagnose specific symptoms. For example, the rectified voltage is 245V DC. Thus, if you want to test the condition of the filter capacitors then connect an oscilloscope and look at the wave form. If it has lots of ripple there is a problem in the filter (this will be accompanied by excessive speaker hash).

All the capacitors before the vibrator are ignition RFI filters and also filter voltage back feed from the vibrator.

The alignment is used for the super-heterodyne internal frequency. The sections in the schematic are IF, detector, Mixer, rectifier, amplifier. The amplifier is a push-pull type which is high quality.

If the parts in the radio are good, chances are what is replaced will not be of as high quality as what has been thrown in the trash.

So about the only argument for blindly replacing those parts to preserve them for posterity?