| Author | Message | ||
     Jeff Costigan Unregistered guest |
I have an idea for a FM Demodulator, without semiconductor diodes or xsistors . Use a Fessenden Baretter ! Use a MicroAmp Bulb . Build a Series Resonant Crkt for the desired frequencies - then have it shunted buy the filament bulb . The Series Res will divert the sidebands into the filament connection where the VHF component of the sidebands will heat the superthin wire by 'Skin Effect' losses . Connected across the Bulb wil be a Low Volatge Battery - which will have a Rheostat in series with it to level the voltage . When modulation is present, the increase of resistance in the filament will change the current flow thru the crkt and will induce a tranmission of charge thru a capacitor connected in a shunt crkt acroos the Battery & Rheostat . High Resistance Headphones will be connected to the capacitor in series . There you have it: FM demodulation by a form of Direct Conversion .  |
