I took a new look at the receiver, did some measurements, and decided to take out the RF amplifier and the AF pre-amp. The receiver works fine without them, another indication that they were unnecessary.
Line-up is now: Band-pass filter, Mixer, VFO, AF amp. I think there is only 49 db of gain in the entire receiver, but it is useable with an un-amplified speaker, and is a bit too loud on ear buds.
Not bad for just 4 transistors. And I think we could do this with just 3 (no need for the VFO buffer).
Linux Mint, QRP, & C / C++ Compilers
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Greetings:
On the bench I'm studying PLL techniques using a sample & hold detector +
VHF circuitry. Currently, I've got nothing to post RF-wise. Another...
4 hours ago
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