I am thinking about building a 1920's-style tunable loop antenna. I have seen two different types: the kind where all the windings are the same diameter and run parallel to each other, and another where the windings run in a decreasing spiral towards the center.

What are the advantages and disadvantages of each type, putting aside construction complexities?

Is one type "earlier" in time-period than the other?

Was one type used with certain circuits more than others?

Are there any plans available for building each type?

I already have enameled magnet wire. Would one type of loop work better with that kind than the other type of loop? I would likely be using 30-gauge wire, as I have the most of that kind.

http://makearadio.com/loops/index.php


Performance of a loop antenna is going to depend somewhat on location. I have never built a spiral (helix) loop. All of mine use parallel wires at the same radius. Lots of old-style loops were spiral wound. See Dave's pages above.

Rich

Thanks!