View Full Version : FM Reception
jcmusic
03-28-2008, 03:28 AM
What would stop me from getting a very strong signal from a station that is really close? I have a FM directional roof mounted antenna 6 element conected to 75 ohm coaxial cable, the cable is about 50ft long the tuner is a Scott 310E. The station puts out 4000 watts and is lss than 5 miles away, the signal meter on my tuner never goes past the # 2 1/2 - 3. Why can I not get a stronger signal?
Jay
Bogframe
03-28-2008, 08:05 AM
4K watts isn't a whole lot of power. You could have blockage from nearby buildings or interference from stronger stations.
ZeroJunk
03-28-2008, 08:33 AM
Could me your S meter is out of calibration. Radio receivers are traditionally calibrated at 50 microvolts per S unit up to S9 and then go logarithmic. I doubt FM stereo receivers are the same but there should be some standard to make the reading mean something. It should be adjustable. If nothing pegs the meter then the meter is "stingy" or you have something wrong in the feedline. If it is just that station then it could be a null caused by who knows what, like when you lose the signal on a mobile at a stop sign, pull up a few feet and it comes back.
electronjohn
03-28-2008, 04:39 PM
Do you have 300 to 75 ohm matching transformers at both the antenna and at the receiver? A mismatch could possibly cause signal attenuation, since the antenna's impedance is 300 ohms and I'm pretty sure the receiver's antenna input is 300 ohms as well...sometimes 75 ohm coax doesn't play well with 300 ohm antennas and radios.
Paul C
03-28-2008, 06:06 PM
Are you getting a clear, noisefree, stereo signal from that station?
jcmusic
03-28-2008, 07:41 PM
Do you have 300 to 75 ohm matching transformers at both the antenna and at the receiver? A mismatch could possibly cause signal attenuation, since the antenna's impedance is 300 ohms and I'm pretty sure the receiver's antenna input is 300 ohms as well...sometimes 75 ohm coax doesn't play well with 300 ohm antennas and radios.
So what do you suggest as a remady because of this?
jcmusic
03-28-2008, 07:42 PM
Are you getting a clear, noisefree, stereo signal from that station?
Yes depending on the weather the signal is clear most of the time, just not very strong according to the meter.
Jay
Paul C
03-28-2008, 11:33 PM
As long as you have clean, noise-free stereo, you don't have a problem.
Punker X
03-29-2008, 03:35 AM
Most Scott's have a Normal and Partial AGC switch, only noticable thing it does it change the meter cal. Try both and see what your meter does. In my experence a 4000 watt station 5 miles away should about peg your meter. Got a couple of local 300 watt LPFM stations that are several miles away that peg my meters.
jcmusic
03-29-2008, 06:40 PM
In my experence a 4000 watt station 5 miles away should about peg your meter. That's what I thought too, thanks Mike I will try it when I get home in the morning.
Jay
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