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Old 10th Oct 2010, 11:35 pm   #10
Alistair D
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Join Date: Jan 2010
Location: Edinburgh, UK.
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Default Re: Product detector circuit

Quote:
Originally Posted by Sideband View Post
Valve or transistor? There are some designs on the Web which look as if they can be built in to existing receivers. I once built a 12 transistor shortwave superhet with a product detector and it worked extremely well. That was nothing more than a simple two transistor circuit (using OC45's I think) so that gives some idea of how long ago it was....!

The only valve circuit I can recall now is in the RSGB handbook that uses an ECC82. I reckon you could build that into the Eddystone without too much trouble and according to the text, can also be used as an 'outboard' item. There are no special parts required and most of the parts should be found in the average scrapbox. Not sure about reproducing the circuit here because of copyright issues.

Remember you'll still need to retain the normal AM demodulator because the product detector will not demodulate AM so some switching will be necessary.


SB
Mods can you help here?
I have the circuits from the copyright 1961 3rd edition and the copyright 1968 4th edition of the RSGB handbook in front of me. The circuits are basically the same standard circuit although component values change and an RFC turns into a resistor. Would we infringe copyright by sending the the cct and text to the OP?

Al
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