diy fm antenna

[kheper]

If you own an FM tuner, but the reception is sub-optimal (in my case, the tuner would not pull in a number of channels in stereo), here's a simple and cheap solution - a flat-top dipole. ~10 ft of coax cable and solder will produce a surprisingly effective antenna. Do the calculations for the exact cable length in the 2nd link before proceeding to fabricate.

The video on YouTube:
http://www.youtube.com/watch?v=KjTshXYsRss

For full bandwidth coverage, the "primary operating frequency" of 98 mHz should be entered. 98 mHz is about half-way up on the FM spectrum:
http://www.ccdxc.org/ant_calc.htm

[dannyr]

That's really neat. I'll have to try it next time that I need a antenna. It looks like a DIY version of the FM Reflect Dipole Antenna sold from CCrane. I have one and it works really well for what it is.

[kheper]

The antenna did boost reception on all FM stations, however, it also magnified interference from the computer. When the computer is on, I cannot pull in 96.1 in stereo, even though the signal indicator registers high. With the computer off, I can pull in this channel in stereo, but the signal indicator is weaker. Below is the tuner I'm using:

[nyazzip]

probably a really stupid question, but do the "designs" apply to mono FM as well...? i have a '50s mono FM tuner in the basement and the reception is generally poor lower on the dial where i spend all my FM time.....

[Shannon Parks]

probably a really stupid question, but do the "designs" apply to mono FM as well...? i have a '50s mono FM tuner in the basement and the reception is generally poor lower on the dial where i spend all my FM time.....

Good write up:
http://transmitters.tripod.com/stereo.htm

Shannon

[kheper]

probably a really stupid question, but do the "designs" apply to mono FM as well...? i have a '50s mono FM tuner in the basement and the reception is generally poor lower on the dial where i spend all my FM time.....

Yes. The antenna will boost the signal for playing in mono as well. With stereo - on some tuners without independent mode switches (one for mono and one for stereo), the signal level needs to be high and the noise level low, or the stereo indicator light will not turn on. But, mono does come in even with a low signal and a high noise level. It would be best to put this antenna outside. Tack it to the house, or screw it to the roof.

[TomMcNally]

Here's how it works on the other side. Here are some pictures of a new 20,000 watt FM I installed in April.

Nautel NV-20 solid State 20kw Transmitter

Front panel which is also available remotely via IP and built in web server

3" transmission line going to antenna switch then up the tower, note giant ferrite rings to keep lightning out

Two ERI FM antennas, top one has an Effective Radiated Power of 50,000 watts, the lower one is 25,000 watts.
These are at 300 to 375 feet on the tower

[kheper]

Nice technology. WFPG (96.9 FM) from Atlantic City, NJ? http://literock969.com

[TomMcNally]

Yes, that's the one. How's it come in up your way?

[kheper]

Even though I'm just outside the coverage area (Philly burbs), I can pull it in - BUT not always reliably. I'll try it with a Kenwood 815, which has good, wide filters and separate stereo and mono mode switches.

http://radio-locator.com is a nice tool.

http://radio-locator.com/info/WFPG-FM

[Geek]

Nautel makes FM too, eh?
Only seen them while touring LW NDB beacon houses.
(engineers are just tickled when everyone is asking aircraft questions on airport tours and this geek comes along and asks to see the NDB )