Products

Stop caring how many I/O pins your Arduino or other micro-controller has. Use the I2C two-wire bus and you can have an digital display, an Si5351, a number of other useful devices, and now a rotary ...
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The circuit of a diode-ring mixer is simple, but making one with good balance, high isolation between inputs, and low-insertion loss is not trivial. It's absolutely doable for a home-brewing Ham, but a wise person chooses ...
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The Hayward-Damm design (published in the December 2007 issue of QST) has long been extolled as excellent, but its complexity has discouraged a number of would-be builders ...
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I wanted to replace the drifty VFO in one of my rigs with a digital solution, but my hand-wired solution was messy, fiddly, and prone to ground loops and digital noise. So I designed a PCB ...
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The performance of a receiver or transmitter depends on careful impedance matching between its sub-systems: its mixers, filters, and amplifiers. Mismatches can cause loss of signal strength, inter-modulation ...
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Adding automatic gain control to a TIA IF amp makes the audio volume of a receiver as predictable as the impedance of the amp itself. AGC keeps strong signals from blasting-out your eardrums ...
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A clean, ripple-free and narrow-skirted "xtal" filter is essential for excellent performance, especially in a receiver. They are, however, among the most difficult builds for a home-brewing amateur to pull off ...
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Dual-gate MOSFETs were once common in Ham radio designs, but no through-hole versions are now available on the market. These little half-inch breakout-boards with pre-soldered SMD versions might make ...
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The operational amplifier–the "op-amp"–was created to do by analog means what we now do digitally: to simulate mathematical operations. In application, though, op-amps have long been used for so-much more ...
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COMING SOON! A breakout PCB for the BFR106 NPN 5GHz transistor. It’s proven to be useful as a “hotter” replacement for more-commonly used devices. With an transition frequency at 5GHz, there’s a lot more gain available ...
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COMING SOON! A general purpose, discrete-component audio amplifier with selectable three or four preamp stages. Based on a design by Richard Anderson, KE3IJ (SK) ...
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