Having visitors this week end put a limit to my radio activities, but one thing got done.
I built (did not take that long) a small balanced amplifier with a TL592 IC. The aim is using it with small loops and ferrite antennas.
The amplifier can be found at Low Frequency Antennas , I made it for a bit higher gain and with a manual tuning capacitor in stead of the varicap, but essentially everything is as in the circuit diagram.
Going through resonance on 80m and 160m the noise increases by 20 - 30dB, so the noise figure and amplification looks good. It looks like the amplifier will support even smaller antennas than my 80-160m tunable loop.
Further experiments with the amp. should include smaller loop/frames and ferrite antennas. It could be interesting to see if the small (50 - 60mm long) ferrite antennas from small transistor radios will work in the indoor noisy environment, or even what they will do outdoors in the open (less noise)
Hidehiko JA9MAT's Self-Quenching Super-Regenerative Receiver from Japan --
AI Gets It Wrong!
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Updated image to show quenching
*Hidehiko reports that in Japan, this is called a "Self Quenching Circuit"
and that it is popular with beginners. He note...
18 hours ago
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