Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: isaac_teller on April 17, 2021, 11:10:40 am
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Hello. I built this stand alone reverb unit. It sounds great but even with shielding of the chassis and the tank it still picks up FM radio stations. I have a battery-powered radio on my workbench. What is really strange is that even if the radio is turned off completely the reverb unit picks up the station that the radio is tuned to, as if there is some kind of link. The radio uses a variable capacitor for tuning, not a digital tuner. Thank you.
https://valveheaven.com/2016/10/the-lamington-reverb-an-easy-to-build-valve-reverb-unit/ (https://valveheaven.com/2016/10/the-lamington-reverb-an-easy-to-build-valve-reverb-unit/)
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Hey dude. You missed April Fools day by a couple weeks. :l2:
Seriously though, I would take that radio across town, tune in some random station, turn it off, bring it back to the workbench, and see if the reverb unit can guess which station it's tuned to.
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Put a grid stopper at the input grid. The lamington lacks that, if I remember correctly. Add a good MF resistor between 10k and 47k.
Doesn't your unit hum? I once built one... over and over, but I couldn't get it not to hum...sold the damn thing