I've been thinking of taking AA7EE's approach at using NM0S's
HiPerMite as the audio chain. I don't fully understand his use of a
tuned BPF, my lack of experience is showing here.
AA7EE Rugster:
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On Sat, Dec 7, 2019 at 10:10 AM W0PWE <j.b.hall@...> wrote:
I like the receiver section of the SST xcvr for an application like this. It even has a simple AGC that works pretty well. You will probably need another stage of audio amplification if you want to use a speaker rather than headphones.
I deviated from the SST design a little and used the internal oscillator in the NE612 for the vfo. With two crystals in parallel (aka super VXO) and a whole lot of experimentation with various inductors I got a tuning range of better than 25KHz. The 40m design uses 4MHz crystals in the IF and 11.046MHz in the VFO. It has been many years but seems like I used 11.059MHz crystals in mine.
Another good option would be the Universal Receiver Kit from Kits and Parts.
73 - Jerry - W0PWE
