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Loktal Radio Tube Store
Loktal tubes were designed for mobile radio use. The proper name is "Loktal" although the
name is sometimes misspelled as "loctal" since "Loktal" doesn't look like the right spelling.
The tubes "lock" into the socket via a spring clamp around the locator pin.
Often the tubes will have a black coating on the pins. This is not as bad as it seems.
The pins are coated with silver to provide a better contact, but silver oxidizes with age
which is the cause of the black color. Silver oxide is still conductive, although not as
conductive as unoxidized silver.
Loktals had a short production life. Sylvania created them in 1938 as an alternative to the
octal base tubes from RCA. By 1947 the tubes had fallen from favor. Probably the biggest
cause of the failure was the difficulty of removing the tube from the socket because of the
locking spring. This often resulted in scraped knuckles. Sometimes the tube base would remain
behind still in the socket because the glue bond broke. Since the only locator indication
on the tube is the base locator, that made it very difficult to figure out how to orient
the tube to reglue it into the base. Generally it ment the tube was thrown out even if it was
The real death of the Loktals was probably driven by the rise of the 7 and 9 pin miniature tubes.
They allowed manufacturers to make smaller radios, and since the miniature tubes didn't have a separate
base, they were cheaper to make. Repairmen liked them because they were easier to replace and took
up less storage space.
Like metal tubes, Loktal tubes were a good idea that didn't work out in real life.
Loktal Radio Tubes
Loktal Radio Tubes
| Type: 7A4, XXL, VT-192, 7A5, 7A6, 5679, 7AD7, 6145, 7AF7, 7AG7, 7AH7, 7AK7|
| Type: 7A7, 7A8|
| Type: 7B4, 7B5, 7B6, 7B7|
| Type: 7B8, 7C4, 1203, VT-243, 7C5|
| Type: 7C6, 7C7, VT-193, 1273, 7E5, 1201, VT-241|
| Type: 7E6, VT-188, 7E7, 7H7, VT-190, 7J7, 7S7|
| Type: 7F7, VT-189, 7F8, 7G7, 1232, 7G8, 1206|
| Type: 7K7, 7L7, 7N7|
| Type: 7Q7, 7R7, 7T7, 7V7, 1231, 7W7||
| Type: 5AZ4, 7X6, 7X7, XXFM, 7Y4, 7Z4|
| Type: 14A4, 14A5, 14A7, 12B7, 14AF7, XXD, 14B6, 14B8, 14C5, 14E6, 14E7, 14F7, 14F8, 14W7, 14Y4|
| Type: 14C7, 1280, 14H7, 14J7, 14Q7, 14R7, 14S7, 14X7|
| Type: 35A5, 35Y4, 35Z3|
| Type: 50A5, 50X6|
How To Order:
Purchasing our Radio tubes is easy.
Click on the desired link above to find the tubes you need.
Then just send us an email indicating the tubes (including quantities) you want.
We will let you know the total price including shipping and handling.
Shipping and Handling Information
Contact MDB Ventures
Due to the highly volatile nature of the tube business, all Prices are subject to change without notice.
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