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Author Topic: UHF mil air  (Read 87425 times)

Offline Josh

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Re: UHF mil air
« Reply #420 on: July 16, 2019, 1942 UTC »
Awesome work, will have to put them into scan. These are kinda similar to the hf channel that used to get more USAF activity than it does now, 6761. That freq was treated like a party line for bombers, tankers, everyone.

On the presets, these vary according to the unit, each craft of a given unit will have the same presets.





Neacp/tacamo/glass flight burning mux on 338.950MHz 1929Z 16JUL19


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Offline MegatonRange

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Re: UHF mil air
« Reply #421 on: July 16, 2019, 2010 UTC »
Awesome work, will have to put them into scan. These are kinda similar to the hf channel that used to get more USAF activity than it does now, 6761. That freq was treated like a party line for bombers, tankers, everyone.

On the presets, these vary according to the unit, each craft of a given unit will have the same presets.

Neacp/tacamo/glass flight burning mux on 338.950MHz 1929Z 16JUL19
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That E-6B is also transmitting on 247.750 Digital WBFM (~ 700 kHz wide signal) 2010 UTC. 16JULY2019. The only other digital WBFM I've seen also came from a E-6B who was transmitting 338.950 (Analog) & 319.875 (Digital)
« Last Edit: July 16, 2019, 2015 UTC by MegatonRange »

Offline Josh

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Re: UHF mil air
« Reply #422 on: July 16, 2019, 2039 UTC »
Hmmm. 700K wide you say? I had 247.750 and figured it was a satcom freq, 319.875 wasn't in scan. Do you have a screenshot of the 700k? Can't get the 319 digi sig via the scanner here but 338.95 is strong.
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Offline R4002

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Re: UHF mil air
« Reply #423 on: July 16, 2019, 2142 UTC »
Awesome work, will have to put them into scan. These are kinda similar to the hf channel that used to get more USAF activity than it does now, 6761. That freq was treated like a party line for bombers, tankers, everyone.

On the presets, these vary according to the unit, each craft of a given unit will have the same presets.





Neacp/tacamo/glass flight burning mux on 338.950MHz 1929Z 16JUL19

I’ve heard chatter on 6761 kHz USB a few times too.

In a weird way, it’s like the pescadores and freebanders on HF.  They like easy-to-remember frequencies.  343.400 MHz, 6666.6 kHz, 6363 kHz, 40.40 MHz, 30.30 MHz, 45.45 MHz, 7676.7 kHz and so many others come to mind. Frequencies like 123.450 MHz and 246.800 MHz are super easy to remember.  Same with the often-overlooked 137-144 MHz and 148-150 MHz VHF bands (25 kHz steps, shared with military users using FM and P25 digital in 12.5 kHz/25 kHz steps). 

I know the Air National Guard in my area uses 140 MHz and 141 MHz freqs (in AM mode) in addition to the usual UHF band frequencies, plus a couple FM tactical band channels (namely 38.500 MHz, 38.550 MHz and 49.725 MHz, I presume there are others I don’t know about) for air to air chatter.  The National Guard also appear to use over a dozen different repeated frequencies in the 148 to 150.8 MHz range for tactical comms, only instead of AM or FM voice, they use encrypted P25 digital voice (12.5 kHz channel steps). 

Oh, also 282.800 MHz - aka “Hard Luck” - which is also the search and rescue/survival radio alternate frequency to 243.000 MHz.  I imagine use of 282.8 MHz for air to air chat is frowned upon, but yes, you’ve got some hard luck if you have to use your survival radio....

I don’t know how many scanner channels you have to work with Josh, but here’s another “button” list for the USAF, apparently used for “auxiliary” purposes, such as air to air chat maybe.

265.500 MHz - “Button 1”
266.600 MHz - “Button 2”
267.600 MHz - “Button 3”
268.600 MHz - “Button 4”
269.900 MHz - “Button 5”
270.100 MHz - “Button 6”
271.600 MHz - “Button 7”
272.700 MHz - “Button 8”
273.500 MHz - “Button 9”
274.800 MHz - “Button 10”
275.800 MHz - “Button 11”
276.400 MHz - “Button 12”
277.200 MHz - “Button 13”
278.400 MHz - “Button 14”
279.400 MHz - “Button 15”
280.500 MHz - “Button 16”
281.200 MHz - “Button 17”
282.800 MHz - “Button 18”
283.000 MHz - “Button 19”
284.200 MHz - “Button 20”
« Last Edit: July 16, 2019, 2304 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers

Offline Josh

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Re: UHF mil air
« Reply #424 on: July 17, 2019, 1907 UTC »
Just had some chatter on "Magnum 5", 357.050 MHz 1904Z 17JUL19
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Offline R4002

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Re: UHF mil air
« Reply #425 on: July 17, 2019, 1931 UTC »
Just had some chatter on "Magnum 5", 357.050 MHz 1904Z 17JUL19

Awesome.  Glad those air-to-air or interplane frequencies are proving fruitful for you.  Similar informal CB-like chat? 
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Offline Josh

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Re: UHF mil air
« Reply #426 on: July 18, 2019, 1959 UTC »
It was air related, musta been at the fringe of my range as they were there long enough for me to see what freq it was and gone.
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Offline R4002

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Re: UHF mil air
« Reply #427 on: July 18, 2019, 2103 UTC »
If you don't mind me asking, what receiver(s) and antenna setup do you use for monitoring 225-400 MHz? 
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Offline Josh

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Re: UHF mil air
« Reply #428 on: July 18, 2019, 2251 UTC »
Right now just a Uniden 9000XLT as the rx, and a Comet or Diamond multiband mobile vertical hanging in the window.

The antenna has designed resonance in the 220 band, I suppose that's close enough to mil air for government work.

In the works is a disconey/lna/hi pass and fmbc filter up 30ft olr so, and then the sdrs will be brought into play.
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Offline R4002

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Re: UHF mil air
« Reply #429 on: July 19, 2019, 1553 UTC »
The multiband vertical probably resonates pretty well in many sections of the 225-400 MHz band, presuming its designed for 2 meters in addition to 1.25 meters.  146 MHz x2 = 292 MHz. 

Discone = win.  That 30 foot increase in elevation will make a real difference too.  I expect your receive capabilities to be significantly increased.  I bet you'll be able to hear a low more VHF/UHF activity in general (30-512 MHz).  Maybe lowband isn't used very often in your area for public safety/business radio stuff, but its still used for military comms.  Presuming the disconey you're putting up is the 25-1300 MHz type, you might be able to hear FM milcom stuff in addition to 225-400 MHz, 137-144 MHz and 148-150.775 MHz. 

Also the SDRs will help a lot.  The VHF low/VHF mid band military activity seems to center around the following bands:

30.000 to 30.600
32.000 to 33.000
34.000 to 35.000 - including 34.900, the National Guard disaster relief common freq
36.000 to 37.000
38.000 to 39.000
40.000 to 42.000 - including 40.500, the VHF-FM version of 121.5/243.0
46.600 to 47.000
49.600 to 50.000

More frequencies to check, although I'm sure most milair comms are in the 225-400 UHF band, with the 137-144/148-150.8 VHF bands coming in second. 


https://www.ntia.doc.gov/files/ntia/publications/section3a.pdf
« Last Edit: July 20, 2019, 1543 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers

Offline Josh

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Re: UHF mil air
« Reply #430 on: July 20, 2019, 1854 UTC »
Expect a lot of ground support ops to employ "cigars";
SINCGARS uses 25 kHz channels in the very high frequency (VHF) FM band, from 30.000 to 87.975 megahertz (MHz). It has single-frequency and frequency hopping modes. The frequency-hopping mode hops 111 times a second.
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Offline Josh

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Re: UHF mil air
« Reply #431 on: July 23, 2019, 2039 UTC »
On mil air antennae, have collected the bits and pieces for one of these;
http://forums.radioreference.com/threads/mt-magazine-uhf-satcom-antenna-project.181378/
Not only is it optimised for milsats it's also good for mil air in the same band.

Also milradiocomms has changed urls;
http://www.milradiocomms.com/index.html
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Offline R4002

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Re: UHF mil air
« Reply #432 on: July 24, 2019, 1314 UTC »
Expect a lot of ground support ops to employ "cigars";
SINCGARS uses 25 kHz channels in the very high frequency (VHF) FM band, from 30.000 to 87.975 megahertz (MHz). It has single-frequency and frequency hopping modes. The frequency-hopping mode hops 111 times a second.

From what I've read on other monitors' logs and from my own VHF low band DXing and monitoring, there's a large amount of ground-to-ground tactical comms using single-frequency aka single channel or SC mode, at least in the CONUS.  The military tactical FM band is the de facto world standard for tactical military comms (even Chinese tanks exported to African militaries come with a 30.000 MHz to 79.975 MHz or 20.000 MHz to 49.975 MHz radio installed!).  Seems like the former combloc countries favor slightly lower frequencies (20-50 MHz or 26-70 MHz or similar instead of 30-88 MHz, although it appears current Russian radios do 30.000 MHz to 107.975 MHz similar ranges).   

Milair comms in my area have been heard on the usual 46.750 MHz, 46.850 MHz and 49.725 MHz frequencies.   When I was still in the Civil Air Patrol I did a SAR exercise at one of the local-ish Army bases and there were signs on base for "FM" frequencies to reach medevac, range control, etc.  I remember 38.500 MHz was one of them, along with 30.150 MHz (I believe) and 38.550 MHz.  38.500 FM was apparently the primary on base Fox Mike frequency for air-to-ground coordination.  It would seem that FH / frequency hopping mode is reserved for electronically hostile situations/locations.  Use of the frequency hopping mode in the US would at the very least require coordination of the hopset frequencies to avoid interference with civilian users of the 30-88 MHz range.   

I did some research, it appears that 38.50 MHz FM (listed as FM 38.5 A/G USE) is still in use for air-to-ground comms at Fort AP Hill, as well as 241.000 MHz AM and the usual 126.200 MHz AM VHF frequency.  Instead of calling 30-88 MHz "VHF" its referred to as "FM" since "VHF" is 108-150 MHz and "UHF" is 225-400 MHz.

On mil air antennae, have collected the bits and pieces for one of these;
http://forums.radioreference.com/threads/mt-magazine-uhf-satcom-antenna-project.181378/
Not only is it optimised for milsats it's also good for mil air in the same band.

Also milradiocomms has changed urls;
http://www.milradiocomms.com/index.html

Awesome.  Do you do any milsat monitoring as well?  255.550 MHz and the other UHF SATCOM FLTSATCOM/FLEETSATCOM peskies notwithstanding, of course. 
« Last Edit: July 24, 2019, 1319 UTC by R4002 »
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Offline Josh

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Re: UHF mil air
« Reply #433 on: July 24, 2019, 1514 UTC »
Back in the day I had all of the 25KHz and wideband channels for the sats programmed into a 2006 and had much more activity than today. Most current activity, sadly, is due to asshats in Brasil and other SA nations using our sats to play cb.
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Offline R4002

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Re: UHF mil air
« Reply #434 on: July 25, 2019, 1325 UTC »
Back in the day I had all of the 25KHz and wideband channels for the sats programmed into a 2006 and had much more activity than today. Most current activity, sadly, is due to asshats in Brasil and other SA nations using our sats to play cb.

Their own private space repeaters! 

Given the proliferation of open-banded 1.25 meter/222 MHz gear (and gear for similar 200 MHz ranges, i.e. the 245 MHz VHF CB band in Thailand), because of that a lot of these Chinese rigs will do 220-270 MHz or something like that after modification, and still others that do 350 MHz to 390 MHz or 350 MHz to 400 MHz.  Apparently the 245 MHz band is extremely popular (80 channels, 245.0000 MHz to 245.9875 MHz, straight 12.5 kHz channel steps) in southeast Asia.  Like India and other places, there's weird use of the 225-400 MHz band for land mobile systems in addition to military aircraft. 

India has several land mobile bands in the 338-340 MHz band (paired with 348-350 MHz, 12.5 kHz channel steps with 6.25 kHz offsets, so frequencies are 338.00625 MHz, 338.01875 MHz, 338.03125 MHz etc.), a short-range FRS or PMR446-like personal radio service from 350.225 MHz to 350.400 MHz (in 12.5 kHz steps) and an additional land mobile allocation from 367 MHz to 400 MHz. 

Japan has another FRS like personal radio service from 348.5625 MHz to 348.8000 MHz (also 12.5 kHz channel steps and 1 watt power output), and the Philippines have their Short Range Radio Service or SRRS at 325 MHz (325.0 MHz to 325.4875 MHz in 12.5 kHz steps with 2.5 watt output power limits). 

245 MHz - 246 MHz, 325 MHz - 325.5 MHz, 338-340 MHz, 348-350 MHz and 367-400 MHz (I know the 380-400 MHz is heavily used in the United States and Europe for trunking systems, TETRA and similar technologies in Europe and elsewhere, Project 25 in the USA for military use).  Altogether that's 38.5 MHz of spectrum within 225-400 MHz allocated to land mobile services.  I'm sure there are other users in other parts of the world I'm not aware of.   

Regardless, those are a lot of potential signals that UHF milsats could accidentally retransmit - not including bootleg or pirate users operating out of band using modified gear. 
« Last Edit: July 25, 2019, 1326 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers