Michael AG5VG finished this receiver last weekend. He hopes to build a CW transmitter using an output of the Si5351. Obviously I defer to Pete on that one. Good going Michael. I think it sounds great and looks even better.
I like all the CuriousMarc videos, but I especially liked this one. Marc and company visited some of the very early launch sites and bunkers at Cape Canaveral. If you thought Apollo tech was crude, take a look back at what they used in Mercury and Gemini. Wow.
I spotted two ham radio receivers. In the first bunker at 10 minutes 28 seconds we see an old National HRO Sixty with the classic HRO dial, much like the one given to me by Armand WA1UQO. (Thanks again Armand!) Note how they attribute one of the early launch disasaters to two diodes in the power supply that shorted due to launch vibration. I hate it when that happens.
In the second bunker we see a Hammarlund HQ-140 at 19 minutes 7 seconds. This was apparently being used as a Frequency Standard (or maybe a time standard?) perhaps receiving WWV at 10 MHz. I note that the frequency knob shows it set for the AM broadcast band...
I really like that variable capacitor. (Where did that come from? How can I get one?)
Charlie's calculations on each of the stages is -- as always -- really nice.
I like the J-310 infinite impedance detector, Charlie's use of solder wick, the wooden base, and his decision to keep the circuitry visible.
I also like Charlie's decision NOT to put that VFO in a metal box. Too often we see projects that try to convince us that the receiver just won't work unless everything is hermetically sealed in submarine-like boxes. Not true! And Charlie's receiver demonstates this.
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