DIY FM antenna, can it be better than radioshack junk?

[rdf]

Originally Posted by tubelab.com

In the US all FM radio stations used to transmit with a predominantly horizontal polarization.

Most stations I've built are circular polarization. Horizontal antennas were reserved for mountainous terrains with crippling multipath. Some sites I inherited were elliptical; instead of the 50% V, 50% H polarization of circular they employed less vertical power to balance the higher gain benefits of horizontal against the penetration benefits of circular.

[hags]

Originally Posted by DF96

AM MW ground wave is essentially vertical polarisation. We were talking about VHF FM. In the UK this started horizontal for best high quality long-distance propagation to fixed roof antennas, then added some vertical to help the majority who wanted portability and were not interested in quality.

That's correct, I was just giving two examples of vertical polarization.

[Colin]

This might be of interest. An experimental DIY FM antenna by John Linsley Hood, specifically designed to be mounted flat against the wall and be as unobtrusive as possible.

Lofty FM Arial.jpg

I built one years ago and it worked quite well but my location is line of site to an FM relay station, just over a mile away. It worked better than the usual rabbit ears wire.

[Nanook]

er...some ready made options: the original poster was looking for an indoor antenna setup. Being a Canuck myself, he should have just looked in his own backyard:

• Magnum Dynalab has the SR-100 "Silver Ribbon" antenna, an easy to tune dipole type, with proper termination. The ST-2 is a verticle type, including a choke. This is similar to the Fanfare. Magnum based in Bramford,Ont.
• UHF has a TV rabbit ear type, that has been apparently "hotrodded", based in Longueuil (Montreal), Quebec.

The J-pole looks interesting as a DIY type. Here's a thought: I get great reception on 99.3 (FM, but not in a metro area) with my Tivoli Model1 radio. It uses cell phone technology to receive and tune stations. Even without an antenna I can get a signal from over 100 miles away. With an antenna I am sure even better. Another option could be an old CB "whip" antenna.

Regarding many of the other "pre-made" and inexpensive options, I have an old Terk tabletop "square" FM antenna/tuneable amplifier, that simply doesn't work. At least not the way I think it should. I would stay away from many of these types, unless also suitable for HDTV, whether rabbit ear types or not. Perhaps I can attach this tuneable amplifier to an antenana and get som distant stations.

[hags]

Really for indoor FM it's hard to beat a big ol' pair of rabbit ears. I've seen these at many local garage sales that seem to dwarf my 10' yagi. You can also check your local CL.

IMO the biggest bang for you indoor FM antenna buck.

[Nanook]

I agree, however the balun should be taken out . There' are significant drops across inexpensive baluns. Get a good balun or just cut the existing one out.

Apparently any "HDTV" rabbit ears are suitable as indoor high performing antennas. I gave a set away to a friend who could not get FM in his trade shop. Now he gets good reception. Often available for $10 or so new

An old CB antenna with a suitable choke (at least I think that's what the thing housed in the cylinderical housing on the ST-2 is). Make your own choke suitable to filter out TV, CB, etc Again, similar to the Fanfare FM-2, and Magnum Dynalan ST-2

[hags]

Absolutely, if you're serious about FM RF/AF performance replace the cheap baluns with coax baluns/chokes or toroids.

[fishwinker]

Wow - a couple of pages of helpful responses to a post on a thread which was years old. Thank you very much everybody. I shall make my way through people's ideas and see where I end up.

Thank you again.