Fltsat/UFO Operation

[N1RGR]

I have a question about the current operation of the US UHF Satcom constellation. I understand that Fltsat and the follow on "UFO" sats are paired up in their Geo slots and operate on the same freqs. My question is...do both sats operate simultaneously on the same freqs or are they only operating the newer UFO follow on sats now? Also does the entire fleet Conus and Atlantic sats all operate on the same band plan and use the same freq pairs?

[brandon]

I have wondered about this as well. I thought they used separate sets of frequencies, but then I notice that some of the freqs have been logged both CONUS and AOR. 255.550 is an example.

[digitalchaos1980]

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Has anyone been able to figure this out yet? I've been a Googling but some stuff conflicts :-/

Chuck

[jsoergel]

Originally Posted by brandon

I have wondered about this as well. I thought they used separate sets of frequencies, but then I notice that some of the freqs have been logged both CONUS and AOR. 255.550 is an example.

It's confusing. I can definitely verify that a lot of the CONUS/LANT freqs are used by both systems, but I can't really work out which is which since I'm using an X-wing. I keep the full bandplan plugged in just in case, but only scanning the voice freqs (above 250).

[N1RGR]

Im guessing much of the service is now being provided by the UFO sats. Fltsat is most likley just being used as a back up. On the other hand there are many active Fltsat freqs listed that are not part of the UFO band plan. So who knows?

[Hooligan]

The band plan stuff dates back to when the satellites were simply bent-pipe transponders that repeated any signal heard on the input (uplink) which was always 33.6MHz down from the output (downlink), & some satellites (especially when they put the UFOs up) share coverage footprints to enhance bandwidth/availability. They didn't want co-channel (uplink or downlink) interference, especially uplink stuff caused by a subscriber that didn't have their antenna pointed correctly, aircraft or ground-mobile terminals transmitting on satcom with antennas that simply send the signal upward but otherwise omni-directional, or with some sneaky-pete satcom on the move stuff, the subscriber's TACSAT antenna was hidden in a contraption worn on their back like a backpack -- not very directional! One I once evaluated was made by Ball Aerospace Corp & looked like I not only stole Second Base, but then glued it to my back (callword used was BIG LEAGUE). Worked poorly, which means high power, which means the people that manage the satellite don't like you & you become the enemy because you're hogging the limited EIRP.

DAMA is cool but it also complicated things, UFO stuff is more sophisticated & of course has crosslinks, but other than some dedicated transponders/circuits & special customers, UHF SATCOM access still requires a validated request & approval, & it's depressing when your life & death mission that's mostly relying on that UHF tacsat circuit ends up receiving a low priority! Thank gosh for Inmarsat & Iridium.

[digitalchaos1980]

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Hooligan, thanks alot for that detailed reply! I now know a bit more and I understand the bandplan thing, I think. So if I wanted to store the satcom freqs to be able to scan through em, I assume then I could use the UFO freqs, of whatever satellite covers my area of the US?

Chuck

[Hooligan]

Originally Posted by digitalchaos1980

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Hooligan, thanks alot for that detailed reply! I now know a bit more and I understand the bandplan thing, I think. So if I wanted to store the satcom freqs to be able to scan through em, I assume then I could use the UFO freqs, of whatever satellite covers my area of the US?

Chuck

Assuming you had the correct bandplan freqs, I guess you could, but I always prefer to search the spectrum. It's hard to just scan the channels, because the majority of what the receiver will stop on is DAMA or other digital modes & not analog voice, so you kinda have to be right there in front of the receiver to keep hittingthe search/scan buttons.

[digitalchaos1980]

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I see what you mean. I have a few channels stored, but I mostly have been just scanning the band back and forth.

Chuck

[brandon]

It's possible to scan but clear activity is few and far between, so having some type of dedicated setup with recording capability is a must. I also scan about 5-10 freqs at a time, otherwise just become overrun by the pirates filling the log.

So far today I had a couple clear comms.
251.850: 5685 clg ??? for radio checks
261.575: Habitat clg 801

I am using a Trivec AV-2011 and Trivec AV-2095 with Advanced Receiver P240-270VDG preamps.

[digitalchaos1980]

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I understand about just scanning the band. Probably better chance of catching something that way.