Dave's Loop Antenna Page

My Dads BCB Loop Antenna

This is the loop antenna my dad built in 1958. Although I was only 8 years old at the time, I knew what this was for and how it worked. The radio is a Fairbanks Morse that my dad bought new in 1936, when he was a teenager. This loop measures 33 inches (84cm) on a side and has 8 turns of wire connected to a 365 pf variable capacitor. There is a band spread capacitor and a switch with a fixed mica capacitor that is switched in to cover the low end of the band. There is a single turn that is connected to the antenna and ground of the radio.
This is the original red paint. I never knew why he painted this red. After thinking about it I realized that the trim on our house was red and this was leftover paint. This loop is still in very good condition and one of my prized possessions. I have always been fascinated with this device and enjoyed tuning the radio and turning the loop. I never built a loop when I was a kid, but I was very influenced by it.

My Dads BCB Loop Antenna Updated 2004

This is the original 1958 tuner.

Renamed to "Bob's Loop"

Top down view of the new tuner.

The "New Loop"

I was not sure I was going to do this change to the loop. After all my dad built it and for me to modify it, was not taken lightly. But I had some good ideas. I wanted to make this loop into a crystal set for the upcoming contest, but I still wanted it as a loop. Not a problem. I took off the original front panel, which will be put away and labeled. I then made the new crystal radio tuner, complete with a "Hobbydyne" type detector and a Bogen audio matching transformer. The only change I had to make that would show, is two holes to mount the transformer.

I used a vernier drive, a dual 365 pf Jackson Brothers variable capacitor. The dial is calibrated in khz. Now I have true one control tuning when using this as a conventional loop. No band spread capacitor, no switch to change to a lower frequency range either.

I think my dad would be proud of me.