Vacuum tubes: Radio tubes, TV tubes, Audio tubes


Are tubes used in radio or TV different from audio tubes used in power amps and preamps?
If they are different (i.e., if tubes used in radios and TVs are different from tubes used in amp/preamps) what are the use of radio and TV tubes?
I don't see any people caring about tube radios and tube TVs as they care about tube amps, but I see a bunch of ads in eBay for selling radio/TV tubes, and just wonder.

128x128ihcho

Showing 1 response by almarg

To add to the good comments above, during the many decades in which tube-based radios and TVs were produced countless different tube types came into existence, and were used in countless different radios and TVs. A small fraction of those tube types, but still a significant number of them, are used in today’s high quality audio components.

That tends to be most true in the case of small signal tubes, that are used in preamps and other line-level components. But a number of power tubes that had been used in certain radios are still used in high quality audio power amplifiers. Examples being the types 45 and 2A3, which were used in high end radios of the early to mid 1930s, and the 6L6 which was used in certain radios starting a few years later. Some of those radios, produced by manufacturers such as E. H. Scott (no relation to the hifi manufacturer H. H. Scott, who came later), McMurdo Silver, and Zenith, were quite elaborate and could be considered to be precursors of modern hifi systems.

In many cases the ads you may see offering large quantities of radio and TV tubes come from tube stocks that had belonged to retired or deceased radio and TV service people. Typically most of those tubes would mainly be of interest to antique radio collectors, while a relatively small fraction of them would be of the types that are still used in today’s audio components.

Regards,
-- Al