TheMadSwede
Premium
join:2001-01-30
Holland, MI
 ·Charter Pipeline
| reply to 91439306
Re: You've got to be kidding me
I hate to turn this into an "interference annoyance" forum, but I live less than a mile from an FM tower for a local station and it jacks with at least 2 other stations that I enjoy.
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Hey - there's this thing called spell check... |
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N0JCG
join:2003-07-18
Minneapolis, MN | Have you filed a complaint? |
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rf_engineer
join:2003-08-04
USA
| reply to TheMadSwede
said by TheMadSwede  :
I hate to turn this into an "interference annoyance" forum, but I live less than a mile from an FM tower for a local station and it jacks with at least 2 other stations that I enjoy.
It may be an issue with your receiver. A lot of pieces of consumer equipment can't deal with strong signals nearby, especially if they fall on the right frequency (aka the "IF image frequency") or are adjacent to a distant station you're trying to receive. So this may not be the fault of the local FM station. You should probably start by talking to the chief engineer of the station and give specifics. They don't like FCC compliants and should be willing to help or at least figure out what's really going on. |
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91439306
15,000 Watts of Bass Power
join:2002-10-16
New Milford, CT
| reply to TheMadSwede
I live within the fall zone of a 50,000-watt FM tower, and ya know what? Not a damned thing anyone can do about it. They were here since 1959 and the houses came in the 1960s.
It is called 'blanketing' interference and radio receivers have to accept it.
It wipes out the ENTIRE FM dial up here, on my Jensen car stereo, and most of the dial on the wife's Sansui. Forget about using a portable or clock radio. 100% obliteration.
Not a damned thing anyone can do about it.
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Take care,
Mark & Mary Ann Weiss
Hear my Kurzweil Creations at: »www.dv-clips.com/theater.htm
Business sites at:
'»www.dv-clips.com
'»www.mwcomms.com
'»www.adventuresinanimemusic.com
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rf_engineer
join:2003-08-04
USA
1 edit | said by 91439306 :
It is called 'blanketing' interference and radio receivers have to accept it.
It wipes out the ENTIRE FM dial up here, on my Jensen car stereo, and most of the dial on the wife's Sansui. Forget about using a portable or clock radio. 100% obliteration.
Realize, though, that it's not necessarily the fault of the radio station. Every receiver contains a filter in the "front end", the first part of the receiver that gets the signal from the antenna. The job of this filter is to attenuate signals that we aren't interested in receiving. A perfect filter would infinitely attenuate unwanted signals. In the real world, though, a front end filter attenuates the unwanted signals a large amount, but some of the unwanted signal gets through the filter. Taken to the extreme, when you have a powerful transmitter next to a receiver, a large amount of unwanted signal will get through. This unwanted signal gets to subsequent stages and gets detected and converted to audio.
Better receivers have better filters and will be able to tolerate strong signals, especially ones that are adjacent or close by your intended receive frequency. One could also put a "notch filter" ( »www.scott-inc.com/html/fmnotch.htm ) in front of the receiver to add additional attenuation to the unwanted signal.
quote:
Not a damned thing anyone can do about it.
Actually, FM stations are required to help resolve blanketing issues in some situations »www.current.org/pb405.html and »www.scott-inc.com/html/73318.htm ...
( Update: Ooops, I didn't see the dates in your post. Buy a notch filter  ) |
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91439306
15,000 Watts of Bass Power
join:2002-10-16
New Milford, CT
| I hung a 1/4-wave shunt across the 300 ohm terminals of the Sansui, and that brought in at least the 5 big CT stations, but I find it unreasonable that a 50,000 watt FM with a tall E-plane pattern is allowed in a residential neighborhood. We didn't have this problem when they used 6 bays of Dialectric antennas. But now that they increased power and decrease to two bays of ERI antennas, we have a 20X increase in ground level field strength.
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Take care,
Mark & Mary Ann Weiss
Hear my Kurzweil Creations at: »www.dv-clips.com/theater.htm
Business sites at:
'»www.dv-clips.com
'»www.mwcomms.com
'»www.adventuresinanimemusic.com
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