searching for mil air on a bct-15

Status
Not open for further replies.

reconrider8

Member
Feed Provider
Joined
Dec 26, 2007
Messages
2,575
Location
Eastern, NC
kinda what i was thinking but if i leave it off i get a ton of dead frequencies but if i have it on i get nothing
 
Joined
Nov 5, 2006
Messages
635
Location
Phoenix Arizona
Absolutely not.

I have done testing to confirm it, but you won't need it.

Reason? There isn't anything else in these bands to interfere really. If I tune into my local F-16 squadron (which I often do), on lets say 316.7, there is no other radio service that is near that, so there is no need for attenuation, and it only will hurt your efforts.

If you want to check, wait until you hear a transmission then hit the attenuation button and watch the radio go silent. They are not the most powerful signals to begin with (don't need to be for aircraft), so 20db of attenuation will usually snuff that transmission right out.
 

ka3jjz

Wiki Admin Emeritus
Joined
Jul 22, 2002
Messages
23,216
Location
Bowie, Md.
Hmm 'a ton of dead frequencies'? sounds like your squelch setting is too low. You want to set it at a level where a weak signal will trip it, but background noise is muted. Not always so easy, particularly if you live in a condo or apartment where everyone's running something that's noisy...

While searching in chunks - say 1 Mhz apiece - is the way to go to find new stuff, I would start off, just to get my feet wet, with the UHF frequencies for the ARTCC(s) that cover your area. This is a good way to test your setup, since the freqs have known activity. Then get over to a NC Yahoo group (there are 2 or 3) and the NC forum for known frequencies.

73 Mike

[edit] There's a wiki article that indexes each of the ARTCC entries we have on the database - just click on the one you want to view (anything in blue or underlined is a link). Don't trust the ATA100 FAA listings, as they are frequently out of date. Use whatever follows it.

http://wiki.radioreference.com/index.php/ARTCC
 
Last edited:
Joined
Nov 5, 2006
Messages
635
Location
Phoenix Arizona
Well, for instance in my local area, the VHF HI band which my FD operates on is congested with all sorts of RF energy including pagers, pirate radio, and legitate services which often exceed their proper bandwidth. Attenuation blocks out most of the junk so you can actually hear what you are trying to hear. I have to run with ATT on to get any mobile signals from PFD. If I am hearing one and switch ATT off the radio goes silent. Without attenuation there is just too much getting into the front end of the radio so I hear nothing. Same for the VHF HI airband in my area, I have to use ATT. UHF and above don't usually require it, but for a few things it helps by reducing noise during transmissions.

For me an attenuator is mandantory, and I wouldn't even consider buying a scanner without it for use with a rooftop antenna around where I live.

This is why back in the old days the PRO-2006 was such a cool thing for me. It came with an attenuator switch when others scanners hadn't had one (even though it was all or nothing, all channels attenuated or not). Everything back then was VHF High just about including Phoenix PD. Hearing mobile units meant having an antenna up high, using good components, and having attenuation.
 
Last edited:

N8IAA

Member
Joined
Dec 19, 2002
Messages
7,045
Location
Fortunately, GA
ok i got most of it but what does it sound like when the att isn't on like a bunch of static or what
Let's make this simple: the att is for attenuation. This allows you to hear strong signals that do not have a PL/DPL associated with them. The signal has metaphorical earplugs put inline to keep it from being overloaded by even stronger signals. You won't hear a lot of static. What you will hear is two or even three systems talking at the same time. If it is a paging tower, you will hear loud digital noise. My advice is, don't use attenuation when listening to milcoms. You will miss a lot of comms with it on. Make a little more sense?
Larry
 

reconrider8

Member
Feed Provider
Joined
Dec 26, 2007
Messages
2,575
Location
Eastern, NC
yea so its just more than 1 network or w/e on the same frequency at 1 time and you hear pretty much just blabber
 

DPD1

Member
Joined
Jul 24, 2005
Messages
1,994
All the attenuation does is basically lower the sensitivity. That's it. It's mainly for when you have a signal so strong that it's making the receiver overload. You might want to use it on say, a very powerful broadcast TV or radio signal. Under normal conditions, you would never want it on. Yes, it will stop annoying 'noise' type signals, but it will also stop weak signals you want to hear. About the only time I might use it, is maybe on an ATC sector that is right near me, and I know that anybody in that sector will come in no problem. Then if I had a weaker noise problem on that same freq, I might turn on att. But that's about the only time. Landing on noise and data is just part of the deal with mil UHF. the band is so wide that it just seems like you're hitting a lot, when actually you'd hit that many on any segment that wide. I would bet you probably get more towards the end after 380. You could maybe cut a lot of that out by just going 225-380. Most of what you want will be in there anyway. Then just keep locking out the noise freqs. Usually after you go around a few times, you'll get most of them.

Dave
www.DPDProductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist
 
Status
Not open for further replies.
Top