My First Vintage Television

[Phil Nelson]

If your radio project was successful, then recapping a TV will be more of the same. A capacitor is a capacitor. I like to be methodical and check off each part on the schematic and parts list when I replace it. If you can't find a schematic, all is not lost. You can usually read the values off the old caps.

Taking a lot of close-up photos of the chassis underside may be helpful, especially if there are crowded areas where you'll need to temporarily disconnect other things to reach a cap.

For an electrolytic can that contains multiple caps, I usually label each lead with a tag before disconnecting, to make sure I reconnect everything correctly.

When the TV is unplugged, it won't jump off the workbench and shock you. Keep your hands out of the high-voltage cage when it's powered up. When you remove the anode lead to the CRT, you can first discharge it by slipping a screwdriver blade under the rubber cap to touch the metal connector, with a clip lead connecting the screwdriver shaft to the chassis. (That's a very cautious approach; I usually just unplug it.)

Otherwise, just use common sense when the chassis is powered up. If you are measuring voltages, follow the old-timer's practice and keep one hand in a pocket. That way, even if your measuring hand accidentally bumps a high-voltage source, you won't create a conductive path that leads from one hand to the other (straight through your heart).

Before you spend a lot of time recapping, it would be good to know whether your CRT is a dud. Perhaps there is a collector club nearby and you could borrow someone's CRT tester. Here's a club list:

http://www.antiqueradio.com/clublist.html

Absent a CRT tester, you can check resistance between the CRT's filament pins. Infinite resistance means the filament burned out and it's a dud. Resistance of a few ohms means the filament is intact and the CRT is worth trying (although it still might be so worn-out that its picture is very dim). You can look up the CRT's data sheet to identify the filament pins:

http://tubedata.tigahost.com/tubedata/

If your CRT's dead, you might want to hold off on restoration work until you locate a replacement.

Happy holidays,

Phil Nelson