Large Ferrite Loop

Here is a description of a large ferrite bar antenna. Can be used tuned or untuned.

A couple of years ago, I bought a large ferrite bar for use as an antenna. It was bought from the Stormwise people here.
It's worked well in a variety of situations. Recently I made an adapter so it fastens to an ordinary camera tripod for rotation and tilt. Here is a photo of the antenna.

I plan on using this on vacation soon, so I needed something that will fit in a suitcase. This certainly will. I would caution anyone who wants to bring this ferrite bar on an airplane to speak with the checkin people first. On Xray, this would look very suspicious.

The ferrite bar works well from LW up to the tropical bands. It does fall off around 3.5MHz. If it is desired to use this as a tuned antenna, than can be done by simply winding around 30-40 turns of wire around the center and connecting that to a variable capacitor. That does increase output a fair amount. Otherwise a preamp such as the DX Engineering RPA-1 here is probably needed.

The pickup is nothing more than a half dozen turns of #14 wire connected to an SO-239 chassis jack. The wire is twisted when it leaves the ferrite rod, and run a couple times through a ferrite choke core. This just isolates the coil from the coax. The core also works well with balanced wire, such as CAT5 or even speaker or AC extension cord wire.

The camera tripod works very well, and is not expensive. It can be used as a desktop or floor setup. The rotate and tilt functions are built right into it. No need to make one and re-invent the wheel. I wish I'd thought of that years ago.

Last update: 18 August 2007