Thursday, April 11, 2013

Speaky AM

Not rocket science here. Just "grabbed" the 8Mhz pre-filtered and buffered output add-on of the Speaky and made a simple 8Mhz AM "receiver" with an IF of 455Khz. Mixer VFO runs at 8.455 since at 7.545 would put if receiving on the 40m (7.090Mhz) band also.

It's just a simple tuned input for an NE602 mixed with 8.455Mhz going thru an 455Khz filter feeding the AM demodulator part of an TCA440, then audio goes to the famous LM386.
Since it's a ongoing experiment will not place schematic for now, but works nice on this simple setup....I can still copy clearly some SSB transmissions, so I'm sure there's little carrier suppression on some rigs...

The main PCB and the TCA440 part were a re-use of one of my VHF air band receivers...another project that had a short live before donating parts...

Have a nice week and weekend!

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