In 1937, RCA released a glass bottle with a metal cap and four pins that would, against all reasonable expectation, still be in active production nearly a century later. The 807 is a beam tetrode vacuum tube — a particular flavor of valve designed for amplifying radio-frequency and audio signals — and it became one of the most prolific, beloved, and stubbornly persistent electronic components ever manufactured.

The 807's distinguishing physical feature is immediately obvious: its plate (anode) connection comes out the top of the tube as a metal cap, not through the base pins. This isn't a quirk — it's engineering. By isolating the high-voltage plate lead from the lower-voltage control electrodes at the socket, the 807 could swing hundreds of volts without arcing across its own pins. It was, in effect, a high-voltage tube wearing a top hat.

Where did they end up? Everywhere.

• WWII military radios — the 807 was a workhorse in transmitters like the SCR-274-N aircraft radio. Allied bombers chattered through pairs of 807s.
• Ham radio — generations of amateur operators built their first transmitters around 807s, because surplus military stock made them dirt cheap after 1945.
• Guitar amplifiers — early Gibson and other amps used 807s before the 6L6 became the standard, and modern boutique builders still occasionally drop them in for the tone.
• Cold War broadcast equipment — Soviet-bloc derivatives (the Г-807) were produced into the 1990s.

Here's where the rabbit hole gets weird: the 807 has a cultural afterlife that no component should reasonably have. Among Australian and British radio amateurs, "807" became slang for a bottle of beer — because the tube's silhouette resembles a long-neck stubby, and because hams traditionally celebrated finishing a transmission by cracking one open. The "Wireless Institute of Australia" had members literally calling their post-meeting beers "807s" through the 1960s and beyond. A vacuum tube became a drink order.

If you've ever held a guitar amp's warm glow up to the light, or thumbed through a 1950s QST magazine, or watched a war movie where a radio operator hunches over a transmitter — you've probably seen an 807, or its direct descendants. The 6L6, the most iconic guitar-amp tube of all time (think Fender Twin Reverb), shares the same internal beam-forming structure invented for the 807's family. Pull a Marshall stack apart and you're looking at the 807's grandchildren.

The truly astonishing part: you can still buy brand-new 807s today. Russian factories — primarily Reflektor in Saratov — produced them well into the 2000s, and NOS (new old stock) inventory remains plentiful. A component designed when Franklin Roosevelt was president is still being shipped to hobbyists who weren't alive when the Berlin Wall fell.