Build your very own superheterodyne radio. Simple to follow instructions with schematics and wiring diagrams! You get a manual, all the parts including silk screened printed circuit board, 4 tubes, sockets, tuning capacitor, Aerial, Oscillator and IF coils, 4 inch speaker, resistors, capacitors, wire, nuts and bolts etc. Four Tube Superheterodyne Radio Kit (Limited Edition)…
DetailsThis was finished months ago and just now I had time to finish the article. LM3916 is a dedicated IC for VU LED meter. Unlike LM3915 which have 3dB step between voltage levels, the LM3916 have nonlinear steps: -20, -10, -7, -5, -3, -1, 0, +1, +2, +3db, just like old school analog VU meters.…
DetailsThis interface is galvanic isolation of the transceiver from PC computer. Audio input and output paths are separated by transformers; optocouplers serve to isolate the digital paths, PTT and CW KEY. It was built for Icom IC-718 but can be used for any other radio. Interface support PTT keying over RS232 RTS (pin 7) and…
DetailsWhen I’m in the shop I usually like jamming to my music but the tunes don’t sound good over the buzz of saws, routers and vacuums. I do what I can to keep the noise down for my neighbors so turning the volume up to eleven is out of the question. Besides being rude to…
Details“Toothpick” Audio CW Filter Kit Variable bandpass helps peak desired signal Audio amplifier will drive speaker to room filling volume In / out switch Use with phones or speaker Will work with other qrp rigs and older receivers Measured peak bandpass 700 to 1000 Hertz Introduction: The “toothpick” is a simple variable bandpass audio filter…
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