Here's another great video from Helge LA6NCA. This is a follow-up to his Altoids Spy Transmitter project. Really well done. Hack-A-Day called this receiver "regenerative" so naturally I was disappointed, but when I watched I realized that it is NOT a regen but is instead a direct conversion receiver. TRGHS. All is right with the world. Thanks Helge! 73
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1 hour ago
He is like VK3YE at 200v, fantastic!! Ed KC8SBV
ReplyDeleteLooking at his schematic, the middle tube, 6AU6 appears to be arranged as a Colpitts regen with "loose" capacitive coupling. Or at least that is what it seems to me. Nice method to control the feedback level. It looks like one of the better regenny designs to me, with the RF buffer. Excellent point-to-point construction, a mix of the old and new.
ReplyDelete73!
I dunno Mike: I was thinking that this could just be another "converter" stage, with the RF oscillator and the mixer/amplifier in the same tube. That second coil just couples incoming RF into the stage. I may be wrong, but I don't see this as a regenerative stage -- just a converter. 73 Bill
DeleteVery nice build!
ReplyDeleteHi Bill,
ReplyDeleteHow about a "Direct-Conversion Receiver with a Regenerative Detector"? It directly converts RF to baseband, so it meets the DC criteria. And the detector is a nice smoothly operating Colpitts oscillator with regen control. He doesn't seem to need much fussing with it to bring in SSB and CW. It almost looks like an "Electron-Coupled Oscillator", but that term usually meant taking RF off the plate, and he is taking audio from there instead. Anyone remember ECO"s??
Great video, his shack (qrz.com) is neat and very impressive.
WN2A
the circuit , please.
ReplyDeleteUh, it is in the video.
DeleteCheck out the above You Tube Link @ ~8:42 in the video.
ReplyDelete