I started playing with the RTL SDR dongles again. I wanted to use them to confirm that my BITX signal is NOT 9 kc wide (it is not). I also wanted to try to confirm the aircraft band frequencies in use in this area.
So I got the HDSDR software running and plugged in the dongle that I had modified for HF use. It worked great, but I could see (literally SEE) that it needed some bandpass filtering and perhaps a bit of RF gain. So today I threw together this device. Dual gate MOSFET (gates tied together) with an LC filter on the gate. Power from Malaysia via the 9V battery.
It works great. It was fun to add a bit of homebrew to an otherwise soul-less commercial receiver. But beware: that waterfall is addictive, even for a hardcore Hardware Defined Radio guy like me.
WTD Schematic for PE 110 PWR Supply For BC 669 Xmtr and Rcvr
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Picked up a BC 669 XMTR/ RCVR at Nearfest- Thanks W3GMS!
Anyway, there is no supply and all sorts of secrets happen behind that
curtain. Does anyone have a ...
5 minutes ago