LiveATC Discussion Forums
Air Traffic Monitoring => Feed Outage/Status Reports => Topic started by: jkaplan on December 04, 2006, 09:52:47 AM
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Hi Folks,
I am experiencing a frustrating problem with the EWR feed. I am a newbie when it comes to scanner/reception issues, so please bear with me...
I utilize a radio shack discone antenna from a site located about 6 miles from EWR. Most of the time, reception of the tower is great. For instance, right now (9:51 EST) it is clear as a bell. However, at times the tower is almost completely inaudible for hours at a time....
Does this have to do with weather? Time of day or night? The difference in reception is so dramatic, yet I know that my configuration is not changing....
What am I missing?
Thanks!
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i check out the feed during and it is good i do here what you are talking about. someetimes you can not here the planes on the ground at all and other times thay are clear as a bell. sometimes you pick up a bleedover from from a local radio station. i have a friend who is a continental pilot who fly the 757 and 767's. thank you again for the kewr feed.
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Jonathan,
I listened for a bit tonight and a couple of times I heard a radio station coming in pretty strong. If it's getting into your scanner strong enough that I can hear it, it's no doubt causing you other front-end problems. We have had pretty good luck with the AOR filters in attenuating FM broadcasters:
http://www.universal-radio.com/catalog/filters/0880.html
If you're feeling even more adventurous, try this one:
http://www.universal-radio.com/catalog/filters/0098.html
It's got a much deeper notch in the FM broadcast band, and should really do a good job at notching out the broadcast stations. It's about double the cost, though.
That's a good start. I'm also hearing a pretty good hum. Send me your mailing address and I'll drop one of the isolation transformers in the mail to you. The last one I tried on KALB helped a lot, so I'm 1 for 1 so far... hopefully it will work for you as well. That won't help reception, but it will make the feed a bit quieter.
Sean
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Sean,
Thanks for offering to send the isolation transformer... I sent you the mailing address in email.
I will check out the other components you mentioned.
By the way, I never did install the inline amplifier that I got.... I need to order a power supply for it.
However, based on what you are saying, sounds like we should do the filtering first, and then think about the amplification. Am I correct?
-Jonathan
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Thank you for pointing out that the bleedover into the feed is from a radio station... I was assuming it was from some sort of transient broadcast (mobile transceiver from an emergency vehicle etc.)...
I didn't realize that a constantly broadcasting source like a radio station could bleed into the frequency but only at certain times... I have a lot to learn about RF communications...!!!!!!!!!!!!!!!!
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Sean,
Btw, I already have a ground loop isolator from Radio shack on the line. Recall that the hum was super loud before it.....
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There seems to be a lot to do up there! Try my audio isolation transformer in place of the RS one. I know the effectiveness of this one, so we'll be working with a known quantity.
As for the order of doing things - filter it first, then amplify it. If you amplify first you're just amplifying noise and other interference the same amount. We have a filter (AB125 I believe) and amplifier online at JFK. There are some noise issues on a couple of the feeds, but I don't think that's as a result of the amp.
I'd go for the more expensive filter just because of the characteristics. It's a much deeper notch, and will really attenuate the garbage. Once that's inline put the amp on and you should have a major improvement.
Sean
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Will do.
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Hi ,I have similar problem in NZ with breakthrough from local Police repeater less than 1km away .
I'm in process of tuning a Cavity Filter to the air band . I have some ex our old now and unused Land Mobile 101 to 108 band now used for FM broadcast .
they provide very good out of band rejection
Steve
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I am setting up the new KLBB (almost there) feed and just got my external antenna up today. I was really looking forward to the better reception, but the opposite happened. I have a BC898T scanner and I could clearly hear airborne aircraft and tower was audible, but with static or "white noise." I could not hear aircraft on the ground except on occasion. Note: This was when the antenna was sitting on the floor inside. Now, with my discone antenna about 30 ft. off the ground and outside, everything turned to ...ya know. I did notice that I can hear radio bleed over onto the departure (119.2) freq. When I manually scan the airband freqs that I have programmed using the rotary dial, the display indicates an "AM" in the upper right corner. Is this an indication that an AM radio station is interfering? I have read the posts about getting filters, but is there a way to know which filter to get or is this just trial and error? Should I get a Jpole antenna that is tuned to the airband and effectively do the same thing? Any help will be greatly appreciated.