Radio tubes

Bob, most old radio tubes are not worth a whole lot, but there are a few antique and/or audiophile tubes that are worth a bundle.

Most TV tubes are virtually worthless. I mean the small tubes found on the TV chassis, not the picture tubes. Actually parts for very early TVs, particularly the picture tubes, are sought after.

I'd first sort them by construction style and pin count. Put all the miniature tubes and compactrons in one basket. These are the ones with an all-glass body and base, with 7, 9 or more stiff wire pins, and basically represent the last generation of tubes. Of this class, the only one that I know of that has real value is the 1L6. They are used in Zenith Transoceanics and some similar radios, and nowhere else, and there is no convenient substitute. Now there MAY be some audiophile-tubes in that basket, depending on where the collection was sourced from, but I'm willing to bet the majority are for TVs and series-string radios.

The next class of tubes would be the octal tubes. They can have either a glass or metal bulb, but have 8 pins in a circle around a central plastic key that locates them in their socket. Many octal tubes will have fewer than 8 pins, but the base has blanks for the unused ones. They came out in the mid-30's and continued in use until the present day (guitar amps, for example). There are a number of these that do have value, and also many that don't. If you don't have too many in this category, just write down the numbers and e-mail me. I can't quote you prices, but I could suggest which ones would be worthwhile to eBay. If you find any 6L6G's or KT88s, they have value to the audiophile crowd. Both are quite big tubes. 5U4s are also big, but they are TV rectifiers, and practically worthless.

A subset of octals are Loktals. They look similar. but they have thin stiff wire pins, and the central key on the metal base has a groove near the tip that clicks into a snap ring in the socket to retain them. Commonly used in Philco car radios as found in Studebakers, and in a few home radios. I'd suggest just putting all the Loktals in a lot and eBay them. They came on the scene in the late 30's, and fell out of use in the early '50's, IIRC.

Prior to octals, you had the "fat pin" tubes, with 4, 5, 6, or 7 pins, two of which were thicker than the rest and next to one another, thus ensuring they only fit one way in the socket. Some of the very old ones had a "globe" envelope quite similar in shape to a common light bulb. Most you will find have a shouldered glass envelope just like many of the later tubes. Find any globe-shaped 45's, and you will make some nice change.

If the etched markings on the glass bulb are obscure, it often helps to chill the tube some, and then breathe on the marking. The mist sometimes brings up the numbers.

is the Website for Antique Electronic Supply, and they have many pages of tubes with the prices they sell 'em for.

Hope this helps a bit, Bob.

Gord Richmond