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Old 24th Sep 2019, 10:13 am   #7
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Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 10,562
Default Re: Vintage Radio and Phonograph cutter schematic

Originally Posted by Levente View Post
It looks like the output transformer primary is also connected to the cutter head. Is this because of the crystal cutting head needs more power than a magnetic head?
The crystal needs to be voltage driven, hence the connection to the output valves anode where a large signal voltage is available.

And the cathode bypass capacitor.. can that capacitor be a non polarized electrolytics? I see that on this schematic is a polarized one but when I check a Fender Champ schema, looks like the bypass cap is a non polarized 25mfd eletrolytic capacitor.?
In the Meissner schematic you posted the polarization symbol (+) for the output valves cathode bypass capacitor has been omitted for some reason, however, being an electrolytic type it is polarized, +ve to cathode.

Rough rule of thumb, capacitors above 1uF are normally electrolytic types.

Non polarized electrolytics were mainly used in loudspeaker crossover networks.

Also found this on web about the early era recording systems etc, it might be of interest:

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