Logan airport

[Algod]

During the day I hear the tower, arrivals, departures, etc., both the controllers, and the pilots. As evening approaches I lose the audio. The radio pauses on tower, etc, and may even show 5 bars, but no audio is heard. Is it a line of sight issue , a change of runways, or what?

 

[doctordialtone]

Is it a line of sight issue , a change of runways, or what?

Propagation changes over time-of-day.

In the extreme case, that's why you can hear AM Radio stations hundreds of miles away as night approaches until sunrise.

 

[Mikejo]

After reading the OP's original post, it says "… Five bars"!

Most likely, the signal has gotten even stronger, and is over powering the front end of your scanner.

At this point, perhaps an attenuator, to lower the signal power coming into your radio might help.

If you're using a scanner with the telescopic antenna, just shorten the antenna and see if that might help etc.

Just my two cents!

 

[Algod]

Thanks gentlemen. they don't stay pinned on 5 bars, usually drop to 2, or 3. I will try to attenuate tonight and see what happens. During the day many flights are overhead, not as many at night.

 

[zerg901]

algod - how far are you from Logan? do you lose tower and departure freqs? all of them? what kind of antenna are you using? do you lose controller and aircraft?

I wonder if maybe you are losing aircraft that are directly overhead of your location?

 

[Algod]

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!

 

[doctordialtone]

I just don't get it

Experiment with the AGC and attenuation. Perhaps you're overloading the front end. (Signal too strong)

To toggle the attenuation for a conventional channel on or off Hold on the channel and press ● then 7(Att). Press Hold to resume. Turn on this setting if you are near other strong signal sources to attenuate about 20 dB. Attenuation sometimes helps to reduce interference and desensitization that strong signals create.

 

[Algod]

I'll give that a try. Thanks

 

[Algod]

I'll give that a try. Thanks

That didn't seem to help.

 

[GTR8000]

Experiment with the AGC and attenuation. Perhaps you're overloading the front end. (Signal too strong)

Uniden's AGC has nothing to do with RF; it only serves to balance the audio levels between loud and soft transmissions.

 

[ATCTech]

Can you receive the ATIS broadcasts from Logan? That would give you a 100% duty cycle transmission to listen for knowing they're always on the air. 127.875 and 135.000 according to the database here.

 

[spanky15805]

Looks like the ASOS is transmitting on 135.275.

 

[spanky15805]

...lol.. Missed that one.

 

[ATCTech]

He does mean he's near Boston/Logan, right? That's what I looked up.

 

[doctordialtone]

I'm 5 miles NW of Logan.

His profile shows Boston, MA.

 

[ATCTech]

'Xactly! I was joking.

 

[spanky15805]

ATCTech...yes sir, you were correct. Couldn't explain how the two brain cells came up with LGU. After I posted I saw his location. I think it really has to do with getting on SkyVector.

 

[spanky15805]

BOS.

 

[spanky15805]

And the last Logan.

 

[zerg901]

just to do a quick review

GENERAL EDWARD LAWRENCE LOGAN INTL - click on Communications - that should be the up to date official FAA list of freqs for Logan - (P = primary - S = secondary)

combining that info with some freqs from some of the Logan charts - its appears that the most important freqs are -

Boston Tower - 128.80

Boston Tower - Helicopters - 124.725

Initial Departure - 133.00

Approach West - 120.60

If I had to guess, I would guess that the fixed transmitter sites for all of those channels are located at Logan Airport - and never change locations - (with the exception that the transmitter site for 120.60 might be west of Logan)