Bruce’s passion for SWLing and single transistor regenerative receivers

Many thanks to SWLing Post contributor, Bruce (VE3EAR), who shares the following:

I live in the village of Saltford, ON, Canada, near the eastern shore of Lake Huron. It’s a quiet location signal wise, and I’m lucky that I have enough property to erect some big antennas. My two favourites are a 1200 foot long terminated Beverage, aimed at 50 degrees true, which targets Europe and the UK. The other is a 333 foot perimeter delta-loop, apex up and oriented north-south. Both antennas are fed with RG-6 coaxial cables and impedence-matching transformers.

I use the loop with a recently acquired Airspy HF+ Discovery SDR and the Gqrx SDR software, in my iMac. I like to listen to amateur activity on 160, 80, and 40 metres, along with the few shortwave broadcast station that are still on the air. I also like to listen to the trans-Atlantic air traffic control stations in Shannon, Ireland and Gander, Canada.

I once heard a U2 spy plane returning from a mission over Russia!

My other hobby is designing and building simple, one transistor regen receivers, most of which tune the AM broadcast band, although I have built a couple covering the lower portion of the HF broadcast bands as well, just for a challenge. All my receivers are built breadboard style.

My favourite of them is one based upon the Vackar oscillator, with the addition of a diode detector and “Benny”, as is used in crystal radios.

Here is the schematic of the Vackar circuit:

The diode and “Benny” connect to the collector of the transistor, then to a pair of home made headphones using two telephone earpiece elements installed in a pair of hearing protectors. The receiver is both very selective and very sensitive. Here is a pic:

Most of the electronics are on a proto-board, which allowed easy component substitutions during the build. When I had it optimized, I decided to leave it that way! The controls, left to right, are on-off switch, regen, fine tuning, main tuning, and range selector switch, hidden behind the reduction drive. Audio is taken from the DET OUT jack, to either the headphones described above, or to an audio amplifier for listening with a speaker.

Bruce, it sounds like you certainly have an excellent spot and excellent antennas for DXing! I love regen receivers as well and radio design can hardly be more simple.

Thank you for sharing!

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6 thoughts on “Bruce’s passion for SWLing and single transistor regenerative receivers

  1. Jordan Dobrikin

    Could / Would you come up with a simple design to add Regeneration to small Loop Antennas?
    thanx
    73 de jordan ve7jjd jjdobrikin @gmail.com

    Reply
  2. Bruce McCreath

    Steve….sorry for late reply….been rather busy lately. The transformer is a Hammond 142D with 200K:1K
    ratio, the latter connected to the headphones. The “Benny” is a 180K resistor in parallel with a 0.22 uF.
    cap, both in series with the transformer primary, to make the DC resistance equal to the AC reactance.
    The regen control is just a voltage divider across the 9V battery. The antenna is coupled with a 3 turn
    link winding at the cold end of the the tank coil.

    Reply
  3. Steve Yothment W4OGM

    Could Bruce give some details on the circuit?
    Where does the antenna connect in the circuit?
    It appears that the Regen control is a potentiometer. Which resistor is this in the circuit diagram?
    The “Benny” apparently is the audio transformer. What’s the impedance ratio for it?
    The battery appears to be a 9V battery, but the circuit diagram shows a 1.2V battery. Which is it?
    What diode, R and C do you use in the detector?
    Thanks for presenting such a simple but probably effective design!

    Reply

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