Tube lineup is like this:
Type 30 triode - transmit MCW oscillator and receive audio preamp
Type 1E7G dual pentode- transmit modulator and receiver audio output
Type 958A 'acorn' triode - two in the TX, wired as a push-pull modulated Hartley oscillator
Type 959 'acorn' pentode- receive RF preamp
Type 958A 'acorn' triode - receive super-regenerative detector
Type 30 triode - 5 MC crystal oscillator, for receiver calibration
My guess is that the TBY was pretty much 'state of the art' in the late thirties. To put seven tubes, two air-variable tuned VFOs, three good-sized bandswitch turrets, and a crystal calibrator into a TBY-sized package must have been considered a marvel of miniaturization in those days. The manual doesn't really quote any specs for the radio, but mentions 5 uV as a reasonable number for receive sensitivity.
The manual for the TBY & TBY-1 here refers to the radio set as 'Ultra-Portable Ultra High Frequency Transmitting-Receiving Equipments', and sez that it was built by the Radio Division of Westinghouse Electric under a contract dated February 26, 1940. A later manual for the TBY-7 downgrades the description to 'Ultra-Portable Very-High Frequency' and states that the later model was built by Colonial Radio Corporation under a June 28, 1943 contract.
If you try to listen to the TBY transmitter with any reasonably modern receiver, you might come to the conclusion that the TBY was the original spread-spectrum radio. The amplitude modulated oscillator design of the TBY's transmitter almost guarantees a good deal of FM in the output, and you'll need very wide filters in your receiver to even hear the old beast. Of course, the regenerative receiver in the TBY is plenty wide - ideal for the task.
I had a TBY-2 as a kid, complete with the 4V lead-acid battery & vibrator pack - worked well with the then-popular Knight-Kit CB-100 three transistor walkie-talkies.
A couple stories here about the TBY... Andy Miller of Salinas, CA worked with the Hollywood folks on the making of "Windtalkers", the 2002 movie about WWII Navajo codetalkers. Andy served as a 'TBY consultant' - he was brought on to provide some real TBYs & accessories from which the Hollywood prop folks could fabricate copies. The prop fab shops built TBY antenna replicas that look good on camera, but the repro antennas do not have a real spring as does the original antenna - the prop just has a larger diameter portion which is painted up to look like a spring. That painted piece is smaller in diameter than the real TBY antenna spring... The canvas repro guys did a nice job on the TBY canvas, but... You guessed it - the canvas guys made the antenna pouch just large enough to accomodate the new repro antenna and now the real TBY antenna won't fit in the repro canvas antenna pouch.
True story here, happened to me back in 1982 or so. I had driven up to Petaluma, CA for a ham swapmeet. It was a small swap, came up only once a year but was usually pretty good for boatanchor stuff. I was wandering around, carrying some sort of green radio that I had just bought. A young fellow in his early teens came up to me and asked me if I knew what a TBY was... (He must have targeted me as a surplus radio hound because of what I was carrying...). I said "sure" and told him that I had owned one when I was about his age, and said that I still had one or two. He asked me if I wanted another one... The story was that his mom wanted him to get rid of his because he kept getting on 27 MCs with it and trashing multiple CB channels with that TBY's fine old modulated oscillator. The local CBers knew who this young gentleman was and had told his mom that he would get in real trouble if he continued to transmit with it... Mom said it had to go, and I guess the young fellow wanted it to go to a good home rather than just send it to the dump. His house was in Penn Grove - we drove down there and his mom confirmed the story (local CBers were lobbying mom pretty heavy I guess...) What I got was a TBY-2, the correct AC power supply, correct antenna, and correct headset. I got back home and of course plugged the thing in right away - as soon as I hit the power switch on the AC supply, I hear some WWII-vintage swing saxophone music blasting out of the headphones!! The last thing that young gentleman was listening to was VOA Delano on the 11 meter shortwave broadcast band (25600-26100 KCs)...
One warning about the TBY - I'm told that the glow-in-the-dark paint on the front panel is quite radioactive, due to the radium content. Mine doesn't glow, but if yours does then it's probably best not to use it as a bedside nightlight...
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