Philco 610: Hums but no reception?

Hey folks,

I am VERY new to restoring anique radios.

What does it mean when the radio hums (from the speaker) but I am getting no stations to come through? All of the tubes work. What could be the issue?

Also, if a tube has a crack in it, is it a complete loss. These are not from the Philco model. Can I test my tubes with a multimeter? How?

Thanks for the help and Season's Greetings!

You might get more results if you post this in the antique radio sub-section of this board.

First of all, yes - a cracked tube is no good. Also, just because the tubes light up does not mean they are good. Just about every township has somebody that can check tubes for you.

Make sure you have a schematic or a tube placement chart that tells you which tube goes in which socket. If you get them in wrong it really won't work. Most of the time the letter/number combination on the tube is worn off so you can't tell what it is. That's why it's important to have a chart of some kind.

A solid hum and no reception? Sounds like the filter caps are shot. The amp needs to be rebuilt. Pull the chassis out and turn it over. If it is full of those wax covered paper capacitors, you need to rebuild the whole thing. The filter capacitors are usually the tall cans with the multiple capacitors inside. They filter the line voltage noise out of the signal. When they get old, they leak and allow that 60 cycle hum to bleed over all the reception.

Help me out here kids, I think it was File-O-Facts or Sam's that used to have schematics on all radios and electronic equipment. You can still get a wiring schematic from an antique radio web site. Just get the make and model number off the radio.

Buy your caps and resistors and get ready to solder.

Remember that the metal chassis on most of these are connected to one side of the power line. Use an isolation transformer when you work on them.

Here is a link to the Rider's schematic on the 610. These schematics are all free so mark this site in your favorites links. You definately need to replace your filter capacitors in that radio. Also be careful when you work with the bakelite condensors under the chassis. If you decide to "airborn" your new caps, make sure to desolder and disconnect the old caps from the terminals. Good luck. If you need any help, feel free to email me at tse1968@45honcho.com.

http://www.nostalgiaair.org/PagesByMode ... 013797.pdf