Logan airport

[zerg901]

Listening to: KBOS App (Final Vector) | Boston, Massachusetts, United States | LiveATC.net - listening to this feed at 12 noon - constant traffic on Final 1 or Final 2 - hearing handoffs to Tower 128.80 and Tower 132.225 - heavy aircraft coming in over Milton - "maintain 170 knots until Milton" - kinda strange that Final 1 and Final 2 are not listed on that FAA page

 

[Algod]

This is what I heard this morning: 128.8 logan tower, 120.6 appr west, 118.25 appr north, 132.225 Boston tower, 121.75 helos, 133.0 depart, 134.05 gate cntl, 124,725 helo, 124.4 logan appr, 121.65 taxi clear, 123.5 chat (weak), 118.5 Hanscom tower. It's now about 6PM and I've heard nothing.

 

[ATCTech]

Something in your house or neighborhood causing an increased level of RF noise that comes on in the late afternoon perhaps? Air band comms are particularly susceptible due to AM mode being sensitive to impulse noise like HPS lighting etc. It sure sounds like your radio is being desensitized by something nearby.

 

[Citywide173]

5mi NW of Logan....that's not exactly in Boston. Are you by chance on the Malden/Melrose line? There's an FAA transmitter just off of the Lynn-Fells Parkway, and it might have a signal that is interfering.

 

[ecps92]

Or due to the traffic patterns [departing/arriving from the North, East or South] they [I have no clue] may change to different RX/TX Sites and as CS173 mentions you may have something nearby interfering or that is your nice day-time transmitter and they change at night

5mi NW of Logan....that's not exactly in Boston. Are you by chance on the Malden/Melrose line? There's an FAA transmitter just off of the Lynn-Fells Parkway, and it might have a signal that is interfering.

 

[Algod]

I live in Medford. Some days every two minutes a plane goes overhead. It slows at night. My thought was other runways are being used, and the signal to the planes was directional, but the radio locks in on the tower with no voice being heard.

 

[ATCTech]

A: The signals from the ATC transmitters are not directional 99.99999% of the time. I can explain when they are for anyone who cares.

B: Runway changes are wind and weather based, not time of day, with the exception of what are called noise abatement procedures.

C: That your radio stops on a frequency and doesn't receive audio is a pretty clear sign of a local source causing EMI or a mixing of 2 signals creating a third that causes the radio to stop scanning and be "overwhelmed" by it. Can you take the radio a distance from your location and see if that changes? That will tell you for sure that it's local, or even very, very local, to your home.

D: Does it receive on the other ATC frequencies if you manually select them? In other words, it's it only one ATC frequency that's being "blocked"? What about things in other bands? NOAA weather broadcasts for example. Are they affected in a similar way at the same time of day?

E: When it does "lock up" does taking the antenna off allow it to continue scanning whatever you have programmed? That's a dead giveaway to a local source of unwanted RF being present. LED/CFL/HPS (street) lights, dimmers, computer hardware, and any number of other electronic devices that may only operate dusk to dawn. And believe it or not, there's an overwhelming amount of non-approved off-shore sourced electronics being sold online that operate illegally in the AM air band. "High power" non-approved cordless phones are a big problem for example. In my career I have personally seen one actually advertised as operating on 121.5 MHz, the international safety/emergency aviation frequency.

I'm certain there's something local to you overloading the radio front end or a similar but slightly more complex internal "birdie" in the radio's RF/IF receiver section.

 

[Algod]

Thanks ATCTech.. Medford is a city that has a petition to abate the plane noise from Logan. It's a base radio in my basement that's connected to an antenna in my attic. Not too easy to move. I'll check NOAA broadcasts tonight. All other bands seem OK, local PDs, Fire, Boston PD, etc.

 

[Citywide173]

C: That your radio stops on a frequency and doesn't receive audio is a pretty clear sign of a local source causing EMI or a mixing of 2 signals creating a third that causes the radio to stop scanning and be "overwhelmed" by it. Can you take the radio a distance from your location and see if that changes? That will tell you for sure that it's local, or even very, very local, to your home.

You must have missed this post:

I'm 5 miles NW of Logan. I lose all commo. This morning all was fine. At about 3PM I lose the commo. This morning I could hear the pilots and tower etc. I have a 30 year old antenna in the attic that I bought from scanner master. This is on my 996T. Just went to the second floor and cranked up the 895XLT with a back of the base 12" BNC antenna, and I hear all the comms. I just don't get it!

If it is local, it's very local, like in the attic (antenna adjacent) or basement (radio adjacent). I think a better test would be to try the back of the set antenna from the 895 on the 396 when it is confirmed that the 895 is receiving and the 396 is not. Even bringing the 396 to the location of the 895 if the basement is too well shielded would give an idea if it's EMI or overload.

To the OP, I don't want to pry into specifics, but if you are in the Fulton Heights or Haines Square area, the FAA tower could very possibly be overwhelming the radio beyond the abilities of the attenuator. I grew up on Gibson St., off Spring (1980's) and it was a horrible reception area, even with a roof mounted antenna (I tried several radio and antenna models over the years.) I could sit in the car outside the house and receive Lawrence Fire, but the radio in the house could barely pick up Quincy Fire when they were still on VHF on either a back of the set or external antenna.

 

[ATCTech]

No, I didn't miss that part of the post. If he wants to find the source he's going to have to make some accommodations to do so. As for your "FAA antenna", exactly what are you referring to? In this particular problem as describe so far, I'm wondering what said FAA tower would be that only operates at specific times. In my 34 years working in the ATC environment I can't name one.

The simple fact that this fault is time of day related should point to something extremely obvious.

 

[Citywide173]

No, I didn't miss that part of the post. If he wants to find the source he's going to have to make some accommodations to do so. As for your "FAA antenna", exactly what are you referring to? In this particular problem as describe so far, I'm wondering what said FAA tower would be that only operates at specific times. In my 34 years working in the ATC environment I can't name one.

The simple fact that this fault is time of day related should point to something extremely obvious.

I am referring specifically to this tower: https://wireless2.fcc.gov/UlsApp/AsrSearch/asrRegistration.jsp?regKey=2686057 which has a very large number of FAA antennas, specifically a large directional antenna pointed directly at Logan airport, which could overload a receiver directly in the path, which a good portion of Medford is in. Having grown up in this area, I know this is an FAA tower because of the warning signs on the fence that surrounds it. I don't think it's necessarily a time of day thing with respect to utilization, but more in regards to propagation.

 

[ATCTech]

If it is local, it's very local, like in the attic (antenna adjacent) or basement (radio adjacent). I think a better test would be to try the back of the set antenna from the 895 on the 396 when it is confirmed that the 895 is receiving and the 396 is not. Even bringing the 396 to the location of the 895 if the basement is too well shielded would give an idea if it's EMI or overload.

That part I agree with completely. Two radios, same location, different results but only at certain time of day. Should be easy to isolate.

 

[Algod]

Yes, I'm a few blocks from Haines Sq. No electronics in the attic, or basement. NOAA radio comes in loud and clear. My 396 has terrible air band reception day, or night. It's the 996T that has me befuddled, it's great in the day time. Yet, no commo in the afternoon.

 

[Citywide173]

Yes, I'm a few blocks from Haines Sq. No electronics in the attic, or basement. NOAA radio comes in loud and clear. My 396 has terrible air band reception day, or night. It's the 996T that has me befuddled, it's great in the day time. Yet, no commo in the afternoon.

Sorry, that's my fault. I meant the 996T. Put a back of the set antenna on it when it stops receiving but the 785 is. That should give you an idea if it's overload.

 

[Algod]

I don't get it. I disconnected the attic antenna from the radio, plugged in the back of the set antenna, but didn't find any difference. Only heard appr north two times that was audible. Plugged in the attic antenna and now receive air band great. I don't move the radio around, so why have I been losing commo in the afternoon? Still don't understand it, but at least have a remedial approach to resolve the issue should it occur again. Thanks all for your patience and help.

 

[Citywide173]

How big is the coax? It is possible that I've been looking at it backwards and you're getting a better signal during the day that degrades at night. The 996T is an old radio and if it's a heavy coax, years of connection could have separated the antenna's connection to the board just enough that the daytime signal get through. NOAA on GBH is a flamethrower, so that might not be a good indicator. Try some of the other NOAA channels at various times to see how they do.

 

[Algod]

I did lose commo a few minutes ago. I turned the radio off then back on and the commo returned. Yes it is heavy coax. It was a struggle to get the BNC adapter off the radio. It hadn't been moved in years.

 

[majoco]

I live 8.3miles from my local airport with a Uniden UBCT8 from an airband folded dipoled via RG6 quad shield coax reasonably new. I'm in the bottom of a valley so can't actually see the airport - I receive aircraft on the ground, the tower ground and approach during the day but after late afternoon only the aircraft on approach clearly, the tower is down in the noise and aircraft on the ground don't lift the squelch. ATIS is down in the noise all the time. My Icom R7000 from a discone is the same. I have no transmitters anywhere near me so my problem is the same as the OP's - an amplifier won't help - just lack of signal. Perhaps everyone should go around and unplug/replug everything once a year or so.... I have a high level area control station transmitter on a high point about 10 miles away and he booms in 24/7 of course.

 

[majoco]

Strangely enough, carrying out some investigation, the tower frequency 120.6MHz comes in much stronger ( no "S" meter) on the UBCT8 from the tuned aircraft band folded dipole through a 1:1 balun to the 75ohm RG6 quad shield than it does into the Icom R7000 from the discone and RG8 good coax - both with no joins straight from antenna to receiver - so I guess the dipole has some good gain. I'll do some testing with my Ailtech NM37-57 signal strength meter.....

 

[spanky15805]

"I turned the radio off then back on and the commo returned. "

Anybody think the scanner might have a problem?