Mr RB
Well-Known Member
Ok humour aside, I've got a little "telephone amplifier" that i got in the 1970's its just a little audio amp and a suction cup coil plugged into it. It was sold for hearing impaired etc to stick it on the telephone handset and amplify the voice picked up from the dynamic earpiece in the handset.
I used it quite a few times to "listen" to bad light switches arcing, carbon resistors in tube amps failing, dodgy capacitors etc. It was a handy little gadget and you got me wondering now where it got stored in all my tons (literally) of old electrical crap.
I'm sure the pickup coil had a lot of turns because it would pick up 50Hz sine fields etc from transformers.
I used it quite a few times to "listen" to bad light switches arcing, carbon resistors in tube amps failing, dodgy capacitors etc. It was a handy little gadget and you got me wondering now where it got stored in all my tons (literally) of old electrical crap.
I'm sure the pickup coil had a lot of turns because it would pick up 50Hz sine fields etc from transformers.