Author Topic: UHF mil air  (Read 15635 times)

Josh

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Re: UHF mil air
« Reply #60 on: June 19, 2017, 1646 UTC »
AAR on 236.65MHz 1640Z 19Jun17.
Century21 (tanker) working various ac, 60 doing a seat swap so apparently multiple pilots onboard for aar training.

Josh

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Re: UHF mil air
« Reply #61 on: June 21, 2017, 1721 UTC »
Neacp/tacamo/glass flight burning mux on 337.3MHz 1620Z 21Jun17.
SSB voice and digital (sounds psk-ish) traffic

Josh

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Re: UHF mil air
« Reply #62 on: June 22, 2017, 1611 UTC »
AAR ongoing 336.100MHz 1550Z 22Jun17.
82 (tanker) working 55, 55 having 3 or 4 pilots that will be doing AAR training, passing around 10k of fuel.

55; 82 able ready
82; 55 clear to contact
55; contact

Josh

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Re: UHF mil air
« Reply #63 on: June 23, 2017, 0004 UTC »
AAR taking place on 343.25MHz 2330Z 22Jun17.
SENTRY31 (possible AWACS, call may be CENTURY rather than SENTRY) working HAPPY53 (tanker).

SENTRY31; HAPPY53, 31, we're at FL210 and will do s turns to allow you to catch up.

HAPPY53; 31, 53, we're doing s turns already so someone needs to to stop doing s turns and speed up.

SENTRY31; 53 what fuel do you have, jp4 or jet 8?
HAPPY53; jet 8.

(all aircraft have multiple trainees, boom operators and pilots, 30k offload)





Josh

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Re: UHF mil air
« Reply #64 on: June 24, 2017, 0232 UTC »
Neacp/tacamo/glass flight burning mux on 366.6MHz 0200Z 23Jun17.

Josh

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Re: UHF mil air
« Reply #65 on: June 26, 2017, 1719 UTC »
Neacp/tacamo/glass flight burning mux on 337.3MHz 1709Z 26Jun17.

Josh

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Re: UHF mil air
« Reply #66 on: June 27, 2017, 0344 UTC »
Neacp/tacamo/glass flight burning mux on 325.4MHz 0330Z 27Jun17.

Josh

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Re: UHF mil air
« Reply #67 on: June 29, 2017, 0046 UTC »
Neacp/tacamo/glass flight burning mux on 337.3MHz 0030Z 29Jun17.

Josh

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Re: UHF mil air
« Reply #68 on: July 01, 2017, 1708 UTC »
Neacp/tacamo/glass flight burning mux on 337.3MHz 1630Z 01Jul17.

Josh

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Re: UHF mil air
« Reply #69 on: July 03, 2017, 1913 UTC »
Northstar C3 Wideband Multiplexed System:
The system onboard the E-6B TACAMO, Air Force 1, The E4B NAOC and other aircraft that provides connectivity into the Northstar network via Ground Entry Points (GEP) is the UHF frequency division multiplexed (FDM) command, control, and communications (C3) system. Both commercial and military networks can be accessed. The onboard components consist of three UHF AN/ARC-171-1H transceivers, five UHF antennas, three MD-1172 modems, three multiplexers, and associated hardware. Currently, the equipment provides three of any combination of the following four services:
- UHF FDM (up to three full-duplex groups of up to15 channels each)
- Airborne Launch Control System (ALCS) data links
- Conventional UHF AM line-of-sight (LOS) (up to three half-duplex channels)
- UHF SATCOM phase shift keying (PSK) receive-only channel (TACAMO broadcast)
A UHF LOS air-to-ground configuration is used in conjunction with the ALCS for communications to intercontinental ballistic missiles. In peacetime, the ALCS is used only during exercises in certain geographic regions within LOS of missile silos. The 75 baud UHF SATCOM data (TACAMO broadcast) is simultaneously broadcast on HF and can be received via that medium. Therefore, much of the time, the third ARC-171 is available for other missions or functions. Nominally, at 25,000 feet, connectivity is provided at an aircraft distance of up to 180 nmi from a GEP. GEP stations are usually located at elevated sites for maximum unobstructed view. Towers are used to elevate antennas in flat areas. Separate transmit and receive omnidirectional antennas are used. All sites are terrestrially connected via AT&T T-1 lines.
The current Air-to-GEP interface is a full duplex UHF FDM link that provides up to 1000 Watts of power and 12 full duplex voice channels per FDM group. GEP sites have at least two radios and two compatible multiplexers. The channels are frequency multiplexed into a 60 kHz baseband group consisting of twelve 3 kHz full duplex voice channels and three orderwire channels plus guard bands and then frequency modulated for transmission on a UHF channel.
Principal sites at Waldorf, MD, Omaha, NE and Lamar, CO are connected via multiple T-1 lines. The primary ground control site for the entire network is the Special Government Operations Center (SGOC) at Waldorf, MD. The secondary ground control site is at Offutt AFB, NE

Courtesy of this pdf, wich is chock full of mil air goodness;
http://www.carmachicago.com/profiles/Milair.pdf

Josh

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Re: UHF mil air
« Reply #70 on: July 03, 2017, 2205 UTC »
"I use a 2 step process to listen to WBFM. First I record the RF signal in FM mode with a bandwidth of at least 120 KHz. I then play that audio file back to tune the sub channels. The audio signal from the E-6 is about 60 Khz wide and the sub channels are spaced 8 Khz appart both USB and LSB. The first video shows the second step. Here we have the E-6 Absentee making the initial contact with the Network coordinator (Gass House). This is done on the sub channel orderwire bravo at 8 KHz LSB. Orderwire alpha is at 0 KHz and orderewire Charlie is at 8 KHz USB. Absentee passes the "flight plan" that lets the Network coordinator know what GEP stations Absentee is going to be using. In this case it's stations Ant House and possibly Affluence. Absentee also passes a mission #. This is the only routine traffic that I hear out on the West coast other than terminating the link at the end of a flight. I do catch a phone call ocassionaly and one is made here on 56 KHz USB. It is a DSN call where Absentee informs someone the are executing exercise GSRV.

https://drive.google.com/file/d/0B52...hmdGFVOWc/view

I rarely get a good signal from the Beale GEP. Here are the better catches.

https://drive.google.com/file/d/0B52...YxV3RQSEE/view

https://drive.google.com/file/d/0B52...VWQUFCSGM/view

STRATCOM GOC can be heard a few times switching to secure comms in this one
https://drive.google.com/file/d/0B52...dEci1tdm8/view

Here is another where I do my best to show the steps I use including a necessary change in the SDR# config file to get the necessary bandwidth in NFM mode. WFM mode will not work. It filters the audio whether the Filter audio box is checked or not.

https://drive.google.com/file/d/0B52...VSZm9uZkE/view

Paul"
https://forums.radioreference.com/military-monitoring-forum/355391-338-9625-a.html#post2785837



The vids linked in the url above describe demodulating the mux stream.

Josh

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Re: UHF mil air
« Reply #71 on: July 12, 2017, 1431 UTC »
Several ac testing some electronic doodad on 248.65 1400Z 12Jul17.

Josh

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Re: UHF mil air
« Reply #72 on: July 16, 2017, 1443 UTC »
Neacp/tacamo/glass flight burning mux on 337.3MHz 1400Z, off at 1441Z 16Jul17. Funny how they dropped as soon as I started to make this post.
« Last Edit: July 16, 2017, 1515 UTC by Josh »

Josh

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Re: UHF mil air
« Reply #73 on: July 16, 2017, 1455 UTC »
AAR ongoing 343.250MHz 1445Z 16Jul17.
Tanker01 with pax who have never seen AAR before, talk about "25 degree bank angle", "71 is going to roll out to 080, correction heading 086" etc. Call sign DEECEE71 may be KC-135R 459th ARW/756th ARS AFRC, Joint Base Andrews MD, appears to be tankers training other tankers in AAR. Comments from the participants kinda give the idea there's 5 tankers in this AAR training. That would make for a good picture.
« Last Edit: July 16, 2017, 1514 UTC by Josh »

Josh

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Re: UHF mil air
« Reply #74 on: July 17, 2017, 1940 UTC »
Neacp/tacamo/glass flight burning mux on 337.3MHz 1910Z 17Jul17.