FM antenna connection

richidoo · February 16, 2010, 11:11:51 AM

I have one nearby FM station that I just started listening to which always has static when playing on my Sansui, all other stations that I listen to are clear. I thought it was another station blanketing me. But all my other radios sound clear.

I was gonna remove the antenna cable and reroute it away from power cords, rectifiers, Sonos smps, etc to try to clean up the static. But it is Blue Jean cables, Belden quad insulated RG6 with Canare connectors, so interference should not be a problem. While I was unscrewing the F connector from the tuna the static stopped just at the last thread before it came loose. I turned it back in and tightened it thinking I was making a bad ground, but the static came back. So now it's hanging on by one thread and sounds clear.

I wondered if I actually broke the inner copper signal connection by pulling it out so far. Yep. When I completely disconnect the antenna cable so ground and signal are not touching anything, it still gets enough signal to tune in, but not enough to distort. But only the strongest stations come through when the antenna is disconnected. And if I pull away the antenna lead more than half an inch from the tuna antenna input jack then I lose the signal.

Sol once proposed that static was caused by too strong a signal and the Sansui was choking on it, seems that once again he is right, but he wouldn't turn down the wattage of his transmitter for me. I could notch the frequency, or maybe a switch to break the signal conductor with a tiny gap. Any other ideas?

Maybe this will be interesting to one of you guys. If not, chalk it up to another minute wasted in audionervosa bliss.
Thanks
Rich

tmazz · February 16, 2010, 01:58:43 PM

Check with an electronics house. I know that cable TV companies use inline attenuators with F connectors on each end to knock down hot signals for customers that are close to the head ends. These should work for you, but unfortunately the attenuation would be across the board. I do not know of any attenuators that would have a notch filter narrow enough to only knock down a single FM station.

richidoo · February 16, 2010, 02:37:32 PM

Hey thanks Tom, they do make narrow notches for stations that are too close and screw up the far away stations. They cost about 150.

tmazz · February 16, 2010, 02:42:37 PM

Wow, I've never seen them, you learn something new every day.

But $150 is a big nut. Perhaps you can find a value in a broadband filter that will fix the station you are having trouble with and still leave enough gain to tune in the other station that you listen to. Last time I looked the broadband attenuators were only a few bucks.

richidoo · February 16, 2010, 03:38:52 PM

That's an idea too. There's a college station kinda far away that is hard to pull in, so I don't want to lose any there. But they are far apart on the dial so a notch should not affect it. I'll probably just unscrew it for a while, see if i can live with that.

Correction: $100
http://www.scott-inc.com/html/fmnotch.htm

Rob S. · February 25, 2010, 09:30:39 PM

Rich,
Forgot to ask you about the basic antenna for my arcam receiver. Need to pick up WV public radio, and have lost the "free" antenna that comes with all receivers. Thanks,

Rob S.

richidoo · February 26, 2010, 05:46:20 AM

Hi Rob, This is the indoor tube antenna I was telling you about
http://www.antennaperformance.com/ Attic Intenna
http://www.antennaperformance.com/subcatagories.asp?CategoryID=1&SubCategoryID=2

They don't list the price, so maybe they are out of stock right now. You have to email or call to find out.

Some other options info:
http://www.amazon.com/C-Crane-FM-Reflect-Antenna/dp/B000EFHPKO
http://www.kyes.com/antenna/antennadex.html
http://www.solidsignal.com/
http://www.gcaudio.com/resources/howtos/antenna.html

Don't buy anything made by Terk. I have bought several of their products over the years and all have been returned. Also, be aware that most whip antennas aka dipole are tuned to pickup either high band (high FM stations) or educational band (low FM stations). Ideally you want one that does both, so whip antenna may not be for you.

Carlman · February 26, 2010, 06:23:43 AM

How hard do you think it would be to make an 'intenna'? For $190 I'd be willing to try. For that kind of money you might as well do a yagi/outdoor antenna.
Another option is to make your own.. here's a good site with the Math: http://www.cyberpoet.net/writes/web/infwiz/spant.html
-C