Pro-82 Vs. Pro-97 (in the milair).

Status
Not open for further replies.

IsCaEs

Member
Joined
Oct 14, 2006
Messages
23
Hello everyone. I have a Pro-82 which can't really recive much of the milAir because it covers only 380-512 MHz in that aera. Inspite of that I still managed to find some freqs.
the only problem is that I recive any transmission with lots of noise and unclearity unless the aircraft is very near to me. My question is why is that? and is it different in the Pro-97?

10x very much.
 
Joined
Jun 5, 2004
Messages
1,227
Location
PNW
Your Pro-82 is probably listening in "FM" mode instead of "AM" mode. Most military aviation transmissions are going to be in "AM".

The Pro-97 picks up the entire military aviation band and should be in proper "AM" mode. Also note that the 380-400 MHz segment has been switched over to DoD trunking use, from what I gather from other posts.
 

IsCaEs

Member
Joined
Oct 14, 2006
Messages
23
Where

Where can I find Specifications of AM/FM reciving in different bands? There are none in the guide...
And are you sure its possible to recive transmissions from AM in FM?
 

ka3jjz

Wiki Admin Emeritus
Joined
Jul 22, 2002
Messages
23,247
Location
Bowie, Md.
Yes it is, utilizing a technique called 'slope detection' - basically listening on a frequency not quite right on, but 1 or 2 kc away. Not very effective, as you've discovered.

The specs on the various public service and civ air bands are quite straightforward - basically, VHF Lo (30-50 Mhz), High (150-174 mhz) and UHF-UHF T (470-512 Mhz) are all FM. Hams have other modes in addition to FM, available for use, found in the 144-148 and 420-450 Mhz bands. Some military stuff resides in the 148-150 mhz range, but for the most part, FM is the rule - though there are some Air National Guard units that I understand use it in AM mode.

Civil Air VHF (108-137 mhz) is basically all AM; a digital mode called ACARS is also found in this band (easily decodeable with the right software and a good shielded connection to a soundcard).

228-400 Mhz is almost all AM; as you've no doubt discovered by now, there are several FM trunking systems in the 380-400 Mhz range, but the 82 cannot listen in nor follow them.
138-144 mhz is used a great deal by Air National guard and National Guard units, with some exceptions (such as the Blue Angels which have used 2 or 3 frequencies in Narrow FM in this band) is basically AM.

That's just a qucik rundown, probably all you need for the 82, which I don't believe has the capability to change the mode of reception regardless of what band you happen to be hearing. 73s Mike
 
Status
Not open for further replies.
Top