Author Topic: Small QRP Receiver build Part-3 it's finished  (Read 1288 times)

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Offline k7rmj

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Small QRP Receiver build Part-3 it's finished
« on: December 25, 2016, 03:52:23 PM »
It is finally completed. Man, that took a lot longer than expected but it was fun  ;D

This little gem actually works much better than expected. When I first turned it on I thought it was not working because it was so quiet. There is almost no background noise generated in the circuit. I'm told this is one of the advantages of a Direct Conversion receiver. You hear both upper and lower sidebands when you tune the receiver.

You can tune in an AM station with the built-in VFO but it is difficult to exactly, zero beat the carrier to get good audio. It does a pretty good job on SSB and CW although with the very sensitive tuning of the VFO it is difficult to tune in an SSB station properly. A much larger tuning knob would help that issue a lot. However, on the plus side, with the VFO you can tune the entire 40 Meter ham band from 7 MHz to 7.300 MHz plus a little.

The VXO, or Variable Crystal Oscillator, does a much better job of tuning in stations. However, a VXO is very limited in tuning range. I got about +/- 8 KHz with it.

Let me know if you enjoyed this. I enjoyed putting it together. All the photos were taken with my Samsung "NOOK" tablet. It doesn't do very well with close up photos any closer than about 6 feet. My apologies for the slightly fuzzy pictures.

73 DE K7RMJ  Frank