Was it a valve amplifier or transistor amplifier?

[genekuli]

hello,
please tell me, if a physicist in 1979 used a high frequency radio amplifier in the USA in a hobby home experiment, would you think it is likely that it was a valve amplifier or transistor amplifier?
that is all the info I have and i would appreciate some wild speculation from such as yourself to logically extrapolate a likely percentage of likelihood.
For example it might have been cost prohibitive for a normal person to use one or the other in those days just for a hobby.
it was a ultra wideband RF amp.
Thank you,
Gene

[Radio Wrangler]

There's no real information to go on, just a date and 'ultra broadband'

Broadband is possible, but very difficult with valve amplifiers. They often have tuned output stages which need peaking every time the frequency is changed and eventually the tuning range is limited by the values of the adjustable components. Typical amateur radio valve power amplifiers might by tuneable from 1.8 to 30MHz but at any one instant they would only be useful over +/- 1% of the tuned frequency. Models would be in the few hundred watts to 1.5kW region for amateur radio. Look up a company called "Henry Radio" for example, also "Erhorn Technical Operateions" (ETO)

Broadband transistor amplifiers from below 1MHz to >200 MHz were used professionally for jobs like EMC testing. Costs would be very high, but these things would amplify the full frequency range at once. Look up the products of a company called "Amplifier research inc." for examples.

David

[M0AFJ, Tim]

Originally Posted by genekuli

hello,
please tell me, if a physicist in 1979 used a high frequency radio amplifier in the USA in a hobby home experiment, would you think it is likely that it was a valve amplifier or transistor amplifier?
that is all the info I have and i would appreciate some wild speculation from such as yourself to logically extrapolate a likely percentage of likelihood.
For example it might have been cost prohibitive for a normal person to use one or the other in those days just for a hobby.
it was a ultra wideband RF amp.
Thank you,
Gene

Hi Gene, If it was high power and broadband I may suggest it was a distributed current tube (valve) amplifier, there were a number of manufacturers of those products in the US including the company I worked for, Amplifier Research Corp. it was a bit too early for solid state especially the type of loads these amplifiers were designed to work in to ( open or short without shutting down or folding back). They were not cheap, also big, noisy and heavy!
Cheers. Tim

[NottsIan]

I don't think we can speculate without knowing approximately what the frequency and power were. Or is it some kind of wideband preamplifier?

[G6Tanuki]

Yes, without knowing whether it was a power-amplifier or a preamplifier, and the frequency-range covered, it's really hard to scry the likely technology.

What was it being used for, I wonder? Transmitting/receiving, or some sort of inductive heating/resonant-excitation/discharge application?

High-power 'broadband' VHF/UHF transistor amplifiers did exist back then - they were generally made by ganging-together large numbers of lower-power amplifiers using splitters/combiners: I've seen one such beastie using 32 separate 1000-Watt-peak 'power-blocks' [it was in a military RADAR].

Small-signal receive amplifiers - solid-state [using GaAsFETs] got to beat the best valves and bipolar-transistors in terms of noise-figure at UHF by the 1970s though the early versions were fragile, static-sensitive things and turned-up their toes at the first rumble of thunder!

[M0AFJ, Tim]

Originally Posted by G6Tanuki

Yes, without knowing whether it was a power-amplifier or a preamplifier, and the frequency-range covered, it's really hard to scry the likely technology.

What was it being used for, I wonder? Transmitting/receiving, or some sort of inductive heating/resonant-excitation/discharge application?

High-power 'broadband' VHF/UHF transistor amplifiers did exist back then - they were generally made by ganging-together large numbers of lower-power amplifiers using splitters/combiners: I've seen one such beastie using 32 separate 1000-Watt-peak 'power-blocks' [it was in a military RADAR].

Small-signal receive amplifiers - solid-state [using GaAsFETs] got to beat the best valves and bipolar-transistors in terms of noise-figure at UHF by the 1970s though the early versions were fragile, static-sensitive things and turned-up their toes at the first rumble of thunder!

Off topic but the biggest we did in the U.K. was 35KW, CW 10kHz to 80 MHz, solid state broadband, would run at full power into an open or short. Installed at a aircraft testing establishment for Rad Sus EMC testing, we also did the monster antenna..