receiving ATC not A/C

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mikebravo

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hello all, I'm a controller at McGuire and a virgin to scanning. Just got a BC246t and I'm wondering why I can't hear the A/C but just the tower and radar controllers. Every now and then I get an A/C but mostly ATC. thxs
 

immelmen

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depends...if your tuned into Civilian VHF controllers and they are talking to military aircraft or vice-versa, then you will only get the band (vhf/uhf) you are on. Tower/radar controllers "simulcast", if you will, on both at the same time for ease of workload.

If its all Civi VHF or all UHF military and your still not getting the A/c then it because one controller is working all the freqs, such a a tower controller working Clarence, Ground, Tower all at the same time and his PTT is keying up all three radios but you cant hear the a/c on the other freq.....happens often at smaller class C airports after hours.

Same can happen when a approach or center controller is working multiple sectors at once during off peak periods.
 

mikebravo

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McGuire AFB, NJ.
understand simulcasting

im an approach controller so I understand the consolidation of positions and simulcasting. If i tune into the primary VHF freq. shouldn't I should be able to hear the replies on VHF? All the A/c we talk to are on one VHF freq because its all general and commercial traffic most of which aren't equipped for UHF. I haven't set the UHFs but they are all in my head so I'll see if the military replys are on that freq.
 

JoeyC

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Most likely your problem is the antenna on the scanner you are using, and/or its location.

Is this the rubber duckie or stock antenna? You probably need an outdoor antenna. I would think that you would hear the aircraft at Center altitudes without too much difficulty regardess of antenna used however.
 

ka3jjz

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Bowie, Md.
If memory serves, the BC246 is not milair (255-400 mhz) capable. A better antenna is in order. That does come with a caveat, however. You see a little handheld cannot deal with the amount of signal a large antenna such as a discone or scantenna might deliver. Overloading (which can show up on the air bands as hearing pagers, FM stations, and other junk where it doesn't belong) is a real possibility. There are filters available that can cut this out, but it increases your costs.

You didn't say anything about how you are using the handheld, or where. Are you using it at home? While driving? These will influence the decisions you need to make about the antenna(s) (and coaxial cable, if you're putting something outside) you will need. Height - getting the antenna away from buildings, trees and other obstructions - and feeding it with the right cable are important.

If you are using a scanner at home just for aircraft (VHF/UHF), you would likely be much better off with an older desktop such as the BC780, 785 or 795. Even some of the older RS PRO models were quite good on VHF, and some covered UHF milair as well. Scanners like the BCT15 cover milair as well as civil air, and I've seen some photos recently having them mounted in a car. I'm not certain that the PRO-2055 (the mobile version of the PRO-97) would fit as well. Older handhelds such as the Uniden BC250 and 296 ought to do well, and since they've been recently discontinued, you could probably get them rather inexpensively. Of course, the BR330 was also recently discontinued, and it too will handle both civil and milair.

Our wiki has lots of information on other scanners, antennas and such. Time for a little reading, and you can start here (anything in blue and/or underlined is a link - both here and in our wiki)

http://wiki.radioreference.com/index.php/Milcom_Receiving_Equipment

73 Mike
 
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mikebravo

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Jul 14, 2008
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Location
McGuire AFB, NJ.
you're right 246t doesn't p/u milair which isn't a factor for me. I was gonna try UHF to trouble shoot the problem of not receiving A/C to see if the A/C were transmitting UHF and tower was simulcasting and i was tuned into the VHF. I have determined that the dorm room i reside in is a MAJOR factor in not hearing the aircraft. Stick the scanner out the window and viola. I have to keep things portable because an outside antenna is not an option so I will check out the link you posted and try and find the best antenna that will compromise between size and performance.

thxs for the help
mb
 

autovon

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Jul 10, 2008
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Iowa
Might try to get a mag mount antenna and put it on the window ledge if there is one.
or make friends with someone over in the comm squadron. Maybe they can hook you up :)
 
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immelmen

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Jun 13, 2007
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If i tune into the primary VHF freq. shouldn't I should be able to hear the replies on VHF?
No, you would not hear ALL the aircraft, just some... because the aircraft's transmissions are not simulcast, only your (you the controller) comms are simulcast. the aircraft's transmissions are only audible on the freq the A/C radio is tunned to.


I hear this happen all the time when flying into class C airports at night. You hear RAPCON give vectors or traffic to a departing aircraft but you cannot hear his read back as I am tuned to approach control and the other A/C is on departure but the controller (you) hears both.
 
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K4DHR

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Olive Branch, MS
Until the towers at some of the sattelite airports open in the morning, several of the approach/departure control frequencies get wrapped up into one or two frequencies during the evening hours around Atlanta.

Even though all frequencies are still in use for transmitter coverage, its the same guy working the same 3 or 4 frequencies and therefore gets simulcasted across each. However, the aircraft use the frequency that corresponds for the particular area they are operating in. You'll hear the controller periodically tell aircraft to switch to "my frequency" (ie., still talking to me, just on a different frequency) when they cross airspace boundaries to make sure the aircraft doesn't get out of range of a transmitter.
 
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