Nuvistors anyone?
73 John F5VLF
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On 13 Sep 2023, at 21:14, Brad Thompson <brad.thompsonaa1ip@...> wrote:
Hello--
Please note that I currently do NOT have a dog in any of the current digital dogfights
which are consuming quantities of various MOSFETs used as final amplifiers in
QRP equipment.
Has anyone considered experimenting with such vintage tubes as the 1T4, 3V4,
1U5, 1LN5, 1A5-GT ?. These are available in the $5.00-$10.00 NOS price range.
Objections in no particular order:
Filament power? 1.4 volts @ 50 mA -- 2.8V@ 100 mA (3V4)
Warm-up time? Consider running the filament at a fraction of full
power; switched by MOSFET
High voltage for the plate and screen? Three 9-volt batteries connected in series = 27 V., falling to
18 volts at dropout.
Bulky, fragile tubes? Don't over-miniaturize the project, and don't use it as a football.
73--
Brad AA1IP
