UHF SATCOM Satellite Downlinks Receivable in North America

Matt Blaze

1 October 2012, updated 16 March 2014



Portable receiving setup I've found a number of excellent web resources (such as uhf-satcom.com and satelliteenwel.de) that list UHF military satellite downlinks, but most of them, for whatever reason, are focused on signals that can be received in Europe.

So I've set about cataloging the downlink signals between 243 and 270 MHz that can be easily and regularly received in North America. This page lists the UHF satellite signals that I can receive and measure with my own (limited) equipment at several (sub-optimal) receiving sites on the East and West coasts of the US. The focus is on geostationary downlinks (which can be received over a large footprint and without the need to calculate their position based on time), but non-geostationary LEO, MEO, and HEO transponders will be included if I happen to catch them. Some samples of the spectrum produced by various transponders can be found here.

UHF military satellites are used chiefly to support the low bandwidth voice and data TACSAT system. This system is used by ground troops, typically employing portable "manpack" transceivers and lightweight tripod-mounted antennas, as well as by aircraft and ships when they travel outside of HF and VHF line-of-sight range. Most military traffic is digitally encrypted, but there are occasional analog clear transmissions as well, usually in FM mode (the transponders will pass almost any modulation that fits within their passband).

But military messages are not the only transmissions that pass through the TACSAT transponders. There are a number of unauthorized and unintentional signals as well, which vary by region. In South America -- principally Brazil -- a large community of "pirate" users have discovered ways to modify VHF amateur radio gear to access the SATCOM system, and their signals comprise the vast majority of the clear traffic going through the transponders that cover the Americas. The satellites over Asia, on the other hand, do not appear to carry much pirate traffic but suffer from a large number of legitimate terrestrial signals on the uplink frequencies that make it into the satellites and that are relayed on the downlink. In particular, many Pacific transponders frequently pick up signals from Russian mobile telephone base stations. These unauthorized and unintentional signals are discussed in more detail in the sections that follow.

This guide catalogs the downlink signals I can intercept in each of two representative geographic areas: in the central New Jersey / Philadelphia area on the East coast and in the San Francisco Bay area on the West coast. This should provide reasonably complete coverage of just about every geostationary transponder downlink in the 243-270 MHz band that can be received in the continental US and most of the rest of the Americas. Because UHF TACSAT footprints are quite wide, any downlink that reaches at least some of the continental US should be receivable on at least one US coast. Any transponder downlink signal received at both of my East and West coastal receiving sites should be receivable almost anywhere in the Americas, while those received at only one will be receivable over only part of the US (precisely how much of the US is covered depends on how far East or West the satellite is positioned over the Equator.)

Any modern, reasonable quality narrowband FM receiver that covers 240-270 MHz should be sufficient for receiving unencrypted UHF TACSAT signals. A spectrum display is helpful for finding the transponders, but not essential once the active transponder channels are known (see this page for details on the different kinds of downlink signals). The downlink signal levels are are relatively weak (they're traveling almost 25,000 miles, after all), making an outdoor antenna with a radiation pattern favoring the satellite is virtually mandatory. A specially-designed circularly polarized directional antenna (such as are used by the military) is ideal but not essential. I have not found receiver preamplifiers, however, to be especially helpful, at least within the satellite footprints.

This is a small personal effort, and while I've tried to be as accurate as possible, it is by no means comprehensive. I'd greatly appreciate any corrections or updates; contact me at mab@crypto.com .

UHF Satellites

Although military communications satellites carry classified traffic, surprisingly little about the actual satellite systems themselves is considered sensitive or kept secret. Detailed information about virtually all man-made satellites (there are currently a bit more than a thousand in operation) can be found in pubic databases. This data is relied upon -- and thus also frequently checked and double checked -- by the amateur astronomy community, with the effect that launches of, and changes to, even "black" military satellites are typically published on the Web quite quickly. I rely here especially on the UCS Satellite Database and the Zarya Database.

Many of the satellites used for tactical military communication operate on UHF frequencies in the 240-318 MHz band. At UHF, the potential "footprint" (coverage area) of a geostationary satellite can be quite large -- about ± 65 longitudinal degrees (this decreases a bit as one moves away from the Equator). The continental US spans from about 67° West (Maine) to about 124° West (Washington state). Most of the known geostationary UHF military satellites with footprints covering all or part of this region are operated by the US military, with a few British and NATO birds mixed in as well. (Actually "UHF" is a bit of a misnomer here, since the downlinks are technically at what is usually considered the upper end of the VHF spectrum, which runs to 300MHz.)

The US divides the world into four regions for UHF satellite purposes: CONUS, covering the Americas; LANT, covering the Atlantic, Western Europe and Africa; IO, covering the Indian ocean, Eastern Europe and Asia; and PAC, covering the Pacific and Australia. Constellations of geostationary "UFO" and "FLTSATCOM" satellites are positioned roughly over the center of each region, yielding effectively worldwide coverage for the US TACSAT system (excluding the arctic and subarctic polar regions, which are covered by HEO and MEO satellites). All of the continental US is within the CONUS constellation's footprint, with the East and West US coasts also touching the edges of the LANT and PAC footprints, respectively. No part of the continental US is within the footprint of the IO region satellites.

Those near either coast thus have access to more TACSAT transponders than those in the center of the country. The regions overlap considerably; Brazil, for example, home to a large number of unauthorized "pirate" TACSAT users, is covered by both the CONUS and LANT footprints.

In all, there are 22 currently known candidate geostationary military communications satellites that are positioned to cover all or parts of the North America and that are either known to or believed potentially to carry UHF transponders. Military satellites are generally known by a variety of names and designators, which makes cataloging them a bit of an exercise in arcane jargon. Also, many "geostationary" satellites actually move around quite a bit with respect to the Earth; their positions listed in different databases can disagree by several degrees over time. Many of these satellites are already well beyond their expected service lifetimes, and could fail or be replaced at any time.

The relevant currently operating satellites I'm aware of are, from East to West:

NameLongitude
(estimated)
Notes
SDS III-2 F5 NRO L10 (USA-155)10.03° WUHF downlinks
WGS3 (USA-221)12.0° WNo known UHF transponders
DSCS III-F6/B12 (USA-82)12.09° WNo known UHF transponders
DSCS III-F12/B11 (USA-153)12.15° WNo known UHF transponders
FLTSATCOM8 (USA-46)14.7° WLANT; bandplans Bravo and Charlie
Skynet 5C (UK)17.83° WBritish; several UHF transponders
UFO7 (USA-127)21.9° WLANT; bandplan Papa
SDS III-6 NRO L-27 (USA-227)30.4 WPossible UHF downlinks
Skynet 4F (UK)34.0° WBritish; several UHF transponders
NATO 4B (USA-98)35.05° WNo known UHF transponders
Milstar DFS1 / Milstar 1-F1 (USA-98)38.9° WPossible SS UHF transponders
DSCS III-F9/B7 (USA-113)52.4° WNo known UHF transponders
DSCS III-B6 (USA-170)52.5° WNo known UHF transponders
Milstar DFS-4 / Milstar 2-F2 (USA-157)67.9° WPossible SS UHF transponders
Milstar DFS 6 (USA-169)90.0° WPossible SS UHF transponders
UFO5 (USA-111)99.4° WCONUS; bandplan November; not in UCS db
UFO6 (USA-114)105.5° WCONUS; bandplan Quebec
DSCS III-F10/B13 (USA-135)130.05° WNo known UHF transponders
DSCS III-F11/B6 (USA-148)135.11° WNo known UHF transponders
SDS III-3 / NRO L12 (USA-162)143.88° WUHF downlinks
UFO4 (USA-108)177.12° WPAC; bandplan Oscar?
UFO8 (USA-138)172.28° EPAC; bandplan Papa?

All these satellites are in geosynchronous orbit (that is, 35,786 km directly above the Equator at their longitudinal position).

Note that even very directional UHF antennas (of any reasonable size) have much wider beamwidths than the typical small satellite dishes used, e.g., for direct broadcast television (which operate at much higher frequencies and with lower received signal levels). The good news is that this means that antenna aiming is much less critical here than it is for setting up a satellite TV dish -- it is generally sufficient to just point in the general direction of the satellite, above the horizon and toward the Equator. The bad news is that it is effectively not possible to authoritatively determine from which satellite a signal emanated using the receiving antenna's heading alone. In practice, we can usually only distinguish signals between satellites spaced at least 20° or 30° apart this way.

Figuring out from which satellite a given UHF signal originated thus requires some guesswork and information beyond just the antenna heading and known satellite positions. Fortunately, some UHF frequency data has been published by the military that can help reduce uncertainty here. An official list of US TACSAT channels can be found in the US TACSAT FM 6-02.90 manual [pdf], but does not specify which channels are carried on which satellites. Frequency bandplans for some satellites (e.g., "Bandplan Novemeber") can be found on satellitenwelt.de. Even then, it is sometimes impossible to be completely certain exactly which satellite hosts a given transponder signal, at least based on unclassified public data.

Most US UHF voice transponder channels use an uplink that is 41.000 MHz above its downlink frequency (although there are a number of exceptions to this rule). The voice transponders are completely analog; unlike repeaters used in land mobile radio systems, they do not demodulate the signals that pass through them. Whatever signal is received by the transponder on the uplink frequency (within the passband bandwidth) is translated directly into a transmitted signal on the downlink. This means that satellite retransmission is independent of the modulation type used, as long as the signal fits within the passband (generally 25 KHz for voice channels). Most current military voice satellite traffic is encrypted and digitally modulated, but, as Brazilian pirates have discovered, conventional analog FM signals are retransmitted just as well. The uplink frequency range is also used for non-satellite military communications (mostly aviation, which uses analog AM, and, in Asia, mobile phone traffic, which uses narrowband FM). Unintended signals from such users will occasionally make their way up to a satellite and be retransmitted on the corresponding downlink channel.

Notes on Methodology

All signals were captured with a Trivec or D&M portable TACSAT antenna just above ground level and manually rotated for maximum signal level. Given a reasonably clear view to the satellite, these antennas generally yield peak received signal levels between about -6 and +6 dBµV for military geostationary transponders, which is more than sufficient for measurement and demodulation on modern receivers without resort to higher-gain (and narrow beamwidth) director elements or preamplifiers. To eliminate any local terrestrial-based sources all signals were captured from at least two different locations in the local area. I used a Rohde and Schwarz PR100 portable receiver to find the signals and measure their characteristics.

Frequency: Frequency (in MHz) is measured from the center of the received downlink signal, generally rounded to the nearest known channel.

Heading: Between the wide beamwidth of the small antennas used and my lack of a completely clear view of the horizon, my receiving arrangement doesn't provide high resolution directional bearings. So I'm just recording a coarse heading where the (manually rotated) antenna maximizes the received signal strength. As noted above, this does not permit distinguishing different satellites whose geostationary slots are near one another. (Reporting bearings with any greater precision than a rough direction would be false advertising here.)

SATCOM spectrum plots Bandwidth: Most satellite transponders transmit a (relatively weak) signal even when they are idle. This consists of broadband noise spread throughout the entire output bandwidth, generally with a steep cutoff at the edges. The distinctive shape of these signals makes transponder downlinks easy to identify, and their exact bandwidth can serve as a simple "signature" for different satellite families. I'm measuring the bandwidth here as the approximate size of the "flat" part of the downlink output, which is not always the same as the published bandwidth of the transponder. For example, US UFO TACSAT transponders "advertise" 25 KHz or 5 KHz of bandwidth per voice or data channel, respectively, but I measure the transponder downlink bandwidths from UFO5, UFO6 and UFO7 as 30 KHz and 6 KHz. The older FLTSATCOM8 voice transponders, on the other hand, have downlinks closer to the same size as their intended channel bandwidths: 25 KHz and 4.5 KHz for voice and data, respectively. See example spectrum capture plots here.

Satellite: The "Probable Satellite and GEO Position" are my best guesses based on the most likely transponders in the direction of maximum signal strength among those listed in unclassified published sources. For the US TACSAT channel numbers, I relied on the US DoD's (somewhat out of date) MULTI-SERVICE TACTICS, TECHNIQUES, AND PROCEDURES FOR ULTRA HIGH FREQUENCY TACTICAL SATELLITE AND DEMAND ASSIGNED MULTIPLE ACCESS OPERATIONS [pdf] (FM 6-02.90) manual. For frequency band-plan information on individual satellites, I rely heavily on the excellent web page at http://www.satellitenwelt.de/uhfmilsat.htm, which is essential reading for anyone interested in UHF satellites. The latter is in German (but is amenable to comprehensible translation via Google Translate).

Notes: The "notes" reflect traffic that I happened to notice during measurements. The ubiquitous Brazilian pirates continue to be well represented on the US CONUS and LANT TACSAT birds as well as on the British Skynet 5C system. ("Portuguese" here refers to the language spoken, not the owner of the satellite.)

East Coast: Central New Jersey / Philadelphia

The East coast of the US is in the primary footprint of satellites that cover the CONUS region (e.g, UFO5 and UFO6) and on the edge of many that cover the LANT region. I believe there are two US LANT region TACSAT satellites currently operating (UFO7 at 23W and FLTSATCOM8 at 14.7 W). We are technically outside the primary coverage area of the LANT constellation, but I have no trouble receiving UFO7 and FLTSATCOM8 transponders here.

Most channels receivable on the East coast have signals from only one satellite. A few, however, have signals from one transponder in the CONUS constellation and another in the LANT constellation. These require more careful antenna aiming to disambiguate the signal source. Note in particular that 255.550 has a 30 KHz transponder on UFO6 (at 105W) and a 25 KHz transponder on FLTSATCOM8 (at 15W). This frequency is very popular with Brazilian pirates, who are within the footprints of both of these satellites; I have occasionally heard both 255.550 transponders in use by pirates simultaneously.

UFO6 (bandpland Quebec) appeared to go off the air some time around 2012-11-02, but most (thought not all) of its transponders were back on the air by 2012-11-09, and the remaining transponders were back by 2012-12-14.

This section last updated 2012-12-14.

Frequency Heading Bandwidth Probable Satellite and GEO PositionNotes
243.8195SSE58 KHzMilstar DFS-4 67.9W?spread spectrum from 243.7905-243.8485
243.915SW6 KHzCh 199 - CONUS: UFO5 99.4W
243.925SW6 KHzCh 200 - CONUS: UFO5 99.4W
243.935SW6 KHzCh 201 - CONUS: UFO5 99.4W
243.945SW6 KHzCh 202 - CONUS: UFO5 99.4W
243.955SW6 KHzCh 203 - CONUS: UFO5 99.4W
243.965SW6 KHzCh 204 - CONUS: UFO5 99.4W
243.975SW6 KHzCh 205 - CONUS: UFO5 99.4W
243.985SW6 KHzCh 206 - CONUS: UFO5 99.4W
244.075ESE6 KHzCh 218 - LANT: UFO7 21.9W
244.085ESE6 KHzCh 219 - LANT: UFO7 21.9W
244.095ESE6 KHzCh 221 - LANT: UFO7 21.9W
244.105ESE6 KHzCh 223 - LANT: UFO7 21.9W
244.115ESE6 KHzCh 225 - LANT: UFO7 21.9W
244.125ESE6 KHzCh 226 - LANT: UFO7 21.9W
244.135ESE6 KHzCh 227 - LANT: UFO7 21.9W
244.145ESE6 KHzCh 228 - LANT: UFO7 21.9W
244.155SW6 KHzCh 229 - CONUS: UFO6 105.5W
244.165SW6 KHzCh 230 - CONUS: UFO6 105.5W
244.175SW6 KHzCh 231 - CONUS: UFO6 105.5W
244.185SW6 KHzCh 232 - CONUS: UFO6 105.5W Ch shared w/ FLTSATCOM8
244.185ESE4.5 KHzCh 232 - LANT: FLTSATCOM8 14.7W Ch shared w/ UFO6
244.190ESE4.5 KHzCh 233 - LANT: FLTSATCOM8 14.7W
244.195SW6 KHzCh 234 - CONUS: UFO6 105.5W Ch shared w/ FLTSATCOM8
244.195ESE4.5 KHzCh 234 - LANT: FLTSATCOM8 14.7W Ch shared w/ UFO6
244.200ESE4.5 KHzCh 235 - LANT: FLTSATCOM8 14.7W
244.205SW6 KHzCh 236 - CONUS: UFO6 105.5W
244.210ESE4.5 KHzCh 237 - LANT: FLTSATCOM8 14.7W
244.215SW6 KHzCh 238 - CONUS: UFO6 105.5W
244.225SW6 KHzCh 239 - CONUS: UFO6 105.5W
245.800ESE34 KHzSkynet 5C: 17.8WPortuguese
248.825SW30 KhzNot in bandplanfirst noticed 20140314
248.845SW6 KHzCh 129 - CONUS: UFO5 99.4W
248.855SW6 KHzCh 131 - CONUS: UFO5 99.4W
248.865SW6 KHzCh 132 - CONUS: UFO5 99.4W
248.875SW6 KHzCh 133 - CONUS: UFO5 99.4W
248.885SW6 KHzCh 134 - CONUS: UFO5 99.4W
248.895SW6 KHzCh 135 - CONUS: UFO5 99.4W
248.905SW6 KHzCh 137 - CONUS: UFO5 99.4W
248.915SW6 KHzCh 138 - CONUS: UFO5 99.4W
248.925SW6 KHzCh 139 - CONUS: UFO5 99.4W
248.935SW6 KHzCh 140 - CONUS: UFO5 99.4W
248.945SW6 KHzCh 141 - CONUS: UFO5 99.4W
248.955SW6 KHzCh 143 - CONUS: UFO5 99.4W
248.965SW6 KHzCh 144 - CONUS: UFO5 99.4W
249.105ESE6 KHzCh 161 - LANT: UFO7 21.9W
249.115ESE6 KHzCh 162 - LANT: UFO7 21.9W
249.125ESE6 KHzCh 163 - LANT: UFO7 21.9W
249.135ESE6 KHzCh 164 - LANT: UFO7 21.9W
249.145ESE6 KHzCh 165 - LANT: UFO7 21.9W
249.155ESE6 KHzCh 167 - LANT: UFO7 21.9W
249.165ESE6 KHzCh 168 - LANT: UFO7 21.9W
249.175ESE6 KHzCh 169 - LANT: UFO7 21.9W
249.185ESE6 KHzCh 170 - LANT: UFO7 21.9W
249.195ESE6 KHzCh 171 - LANT: UFO7 21.9W
249.205ESE6 KHzCh 173 - LANT: UFO7 21.9W
249.215ESE6 KHzCh 174 - LANT: UFO7 21.9W
249.225ESE6 KHzCh 175 - LANT: UFO7 21.9W
249.235SW6 KHzCh 176 - CONUS: UFO6 105.5W
249.245SW6 KHzCh 177 - CONUS: UFO6 105.5W
249.255SW6 KHzCh 179 - CONUS: UFO6 105.5W
249.265SW6 KHzCh 180 - CONUS: UFO6 105.5W
249.275SW6 KHzCh 181 - CONUS: UFO6 105.5W
249.285SW6 KHzCh 182 - CONUS: UFO6 105.5W
249.295SW6 KHzCh 183 - CONUS: UFO6 105.5W
249.305SW6 KHzCh 185 - CONUS: UFO6 105.5W
249.315SW6 KHzCh 186 - CONUS: UFO6 105.5W
249.325SW6 KHzCh 187 - CONUS: UFO6 105.5W
249.335SW6 KHzCh 188 - CONUS: UFO6 105.5W
249.345SW6 KHzCh 189 - CONUS: UFO6 105.5W
249.355SW6 KHzCh 191 - CONUS: UFO6 105.5W
249.375SW30 KHzNot in bandplanfirst noticed 20140314
249.450ESE6 KHzSkynet 5C: 17.8W
249.500ESE34 KHzSkynet 5C: 17.8W
249.550ESE34 KHzSkynet 5C: 17.8W
249.918ESE34 KHzSkynet 5C: 17.8WPortuguese
250.075WSW25 KHzSDS III-3 (USA 162) 143.88W
250.130ESE6 KHzSkynet 5C: 17.8W
250.350SW?CONUS: UFO5 99.4W?narrow carrier
250.450SW30 KHz?normally distributed peaks over 30 KHz
250.550ESE25 KHzCh 5- LANT: FLTSATCOM8: 14.7W or UFO7 21.9Wwide data; probably FLTSATCOM8
250.650SW30 KHzCh 7 - CONUS: UFO6 105.5W
251.275SW30 KHznot in bandplan - CONUS ?first noticed 20140314
251.325SW30 KHznot in bandplan - CONUS ?first noticed 20140314
251.325ESE37 KHzSDS3-F2 (USA155): 10.3Wdata; check status
251.700ESE34 KHz?Possible LEO/HEO
251.850SW30 KHzCh 9 - CONUS: UFO5 99.4Woff air 20140314
252.050ESE30 KHzCh 11 - LANT: UFO7 21.9W
252.150SW30 KHzCh 12 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8; off air 20140314
252.150ESE25 KHzCh 12 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6
253.500ESE36 KHzMilstar DFS4 67.9W/Milstar DFS1 39.7W?Portugese at 1600Z-20120930
253.550SW30 KHzCh 13 - CONUS: UFO5 99.4W
253.750ESE30 KHzCh 15 - LANT: UFO7 21.9WPortuguese 1600Z-20120930
253.850SW30 KHzCh 16 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8;
253.850ESE25 KHzCh 16 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6
253.900ESE34 KHzSkynet 5C: 17.8WPortugese at 1600Z-20120930
254.100SW30 KHzCh 241 - CONUS ?first noticed 20140314
254.150SW30 KHzCh 192 - CONUS ?first noticed 20140314
255.250SW30 KHzCh 17 - CONUS: UFO5 99.4W
255.450ESE30 KHzCh 19 - LANT: UFO7 21.9WPortuguese + "twin peak" data 20120930
255.550SW30 KHzCh 20 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8; Portuguese 20120930
255.550ESE25 KHzCh 20 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6; Portuguese 20121003
256.375E25 KHz?data - maybe HEO sat
256.600ESE34 KHzSkynet 5C: 17.8WPortuguese
256.850SW30 KHzCh 21 - CONUS: UFO5 99.4WCh shared w/ FLTSATCOM8; data bursts 20120930
256.850ESE25 KHzCh 21 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO5
257.050ESE30 KHzCh 23 - LANT: UFO7 21.9W"buzzy" data
257.150SW30 KHzCh 24 - CONUS: UFO6 105.5WPortuguese
257.425ESE36 KHzSkynet 4F 34.0WPortuguese? music
257.550SW30 KHzUK Channelfirst noticed 20140314
258.350SW30 KHzCh 25 - CONUS: UFO5 99.4W"buzzy" data
258.550ESE30 KHzCh 27 - LANT: UFO7 21.9Wdata bursts
258.650SW30 KHzCh 28 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8
258.650ESE25 KHzCh 28 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6
258.775ESE25 KHz?SDS 3-F2 (US155) 10.3Wdata
260.375SW30 KHzCh 46 - CONUS: UFO5 99.4W
260.425ESE30 KHzCh 48 - LANT: UFO7 21.9Wdata bursts
260.475SW30 KHzCh 50 - CONUS: UFO5 99.4W
260.525ESE30 KHzCh 52 - LANT: UFO7 21.9W
260.625SW30 KHzCh 56 - CONUS: UFO6 105.5WPortuguese child? 20120930
260.725SW30 KHzCh 60 - CONUS: UFO6 105.5W
261.400ESE??periodic/intermittent carrier
261.450SE30 KHzFLTSATCOM8 14.7 KHz?Portuguese 20121014; no idle transponder signal
261.575SW30 KHzCh 71 - CONUS: UFO5 99.4W
261.675SW30 KHzCh 75 - CONUS: UFO5 99.4W
261.775SW30 KHzCh 79 - CONUS: UFO5 99.4W
261.875SW30 KHzCh 83 - CONUS: UFO5 99.4W
262.125SW30 KHzCh 90 - CONUS: UFO6 105.5W
262.200ESE34 KHzSkynet 5C 17.8Wsignal partly overlaps w/ 262.225
262.225SW30 KHzCh 94 - CONUS: UFO6 105.5WPortuguese; partly overlaps w/ 262.200
262.325SW30 KHzCh 98 - CONUS: UFO6 105.5W
262.425SW30 KHzCh 102 - CONUS: UFO6 105.5WPortuguese
262.675SE?SDS III-6 F5 30.4W?data
263.225WSW?SDS III-3 F3 143.8Wdata
263.575SW30 KHzCh 109 - CONUS: UFO5 99.4W
263.625ESE30 KHzCh 111 - LANT: UFO7 21.9Wdata bursts
263.675SW30 KHzCh 113 - CONUS: UFO5 99.4W
263.725ESE30 KHzCh 115 - LANT: UFO7 21.9Wdata bursts
263.825SW30 KHzCh 119 - CONUS: UFO6 105.5W
263.925SW30 KHzCh 123 - CONUS: UFO6 105.5WB/c audio @ .020
265.250SW30 KHzCh 29 - CONUS: UFO5 99.4Wdata
265.450ESE30 KHzCh 31 - LANT: UFO7 21.9WPortuguese
265.550SW30 KHzCh 32 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8
265.550ESE25 KHzCh 32 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6
266.750SW30 KHzCh 33 - CONUS: UFO5 99.4W
266.950ESE30 KHzCh 35 - LANT: UFO7 21.9W
267.050SW30 KHzCh 36 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8
267.050ESE25 KHzCh 36 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6
267.550WSW30 KHzSDS III-3 (US162) 143.8Wdata
267.825SW30 KHznot in bandplan - CONUS ?first noticed 20140314
267.925SW30 KHznot in bandplan - CONUS ?first noticed 20140314
268.150SW30 KHzCh 37 - CONUS: UFO5 99.4W
268.350ESE30 KHzCh 39 - LANT: UFO7 21.9W
268.450SW30 KHzCh 40 - CONUS: UFO6 105.5WSpanish lang broadcast; Ch shared w/ FLTSATCOM8
268.450ESE25 KHzCh 40 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6
268.675ESE30 KHzSDS III-2-F5 (US155) 10.03Wdata
269.650SW30 KHzCh 41 - CONUS: UFO5 99.4W
269.850ESE30 KHzCh 43 - LANT: UFO7 21.9Wdata bursts
269.950SW30 KHzCh 44 - CONUS: UFO6 105.5WCh shared w/ FLTSATCOM8
269.950ESE25 KHzCh 44 - LANT: FLTSATCOM8 14.7WCh shared w/ UFO6

West Coast: San Francisco Bay Area

The West coast of the US is in the primary footprint of satellites that cover the CONUS region (e.g. UFO5 and UFO6) and on the edge of many that cover the PAC region (e.g., UFO4 and UFO8). Most of the PAC satellites are a bit weaker here than the CONUS birds are, at least from my SF Bay Area vantage point. Overall, the PAC region satellites carry several more transponders than their LANT region counterparts, and so those on the West coast are in range of a few more downlinks across the band than are those in the East.

The Pacific constellation is a bit less well documented than the Atlantic region, and I've had to make a few educated guesses and fill in a few missing details from the existing open literature based on my measurements. satellitenwelt.de lists the two main PAC region TACSATS, UFO4 (at 177.1°W) and UFO8 (at 173.3°E), as following bandplans Oscar and Papa, but does not specify which satellite follows which bandplan. I measure the Oscar downlink channels at a bearing that is rather distinctly, if only slightly, to the SW of the Papa channels. So I'm concluding (tentatively) that UFO4 (the Easternmost of the two) follows Oscar and UFO8 follows Papa.

There have also been a number of "mystery downlinks" over the Pacific whose origin is not obvious from the published sources to which I have access. In particular, during October 2012 there were strong downlink signals from the SW on many (but not all) of the frequencies used by CONUS UFO6 (bandplan "Quebec"), but no satellite on this bandplan was listed in any database for the PAC region. (Because these channels have two downlink signals coming simultaneously from different directions on them, it's difficult for me to take a more accurate bearing than just "generally SW", and so I can't really tell where these were coming from is with respect to the known positions of other satellites.) These transponders went off the air some time in early November 2012; time will tell whether they will reappear. There are also several signals (e.g., 267.925) on frequencies that do not appear in any US or NATO bandplan.

As on the East coast, Portuguese-speaking (presumably Brazilian) pirates are the main source of clear (FM) traffic through the voice transponders, although less of this traffic can be heard on the West coast than on the East coast. This is because Brazilians can choose either CONUS or LANT satellites (being within both footprints), but the Western US is well outside of the LANT footprint. So only the portion of Brazilian traffic that goes through CONUS constellation satellites can be received in the Western US.

While the PAC constellation may lack Brazilian pirates, it has its own source of unintended signals not found on CONUS or LANT satellites: Russian mobile telephones. Some areas of Russia (and the former Soviet Union generally) are still served by a non-cellular trunked analog mobile telephone system, called Altai, that operates in the 300-344 MHz range. Certain TACSET uplink frequencies are shared with those of Altai base station outputs, whose signals often make their way up to (and are retransmitted by) PAC region transponders whose uplinks are on those frequencies. The Altai system dates from the Soviet era and long predates the UHF TACSAT system, so this unintended traffic has presumably been an issue from the very beginning of TACSAT deployment.

UFO6 (bandpland Quebec) appeared to go off the air some time around 2012-11-02, but most (thought not all) of its transponders were back on the air by 2012-11-09, with the remaining transponders back on the air by 2012-12-14.

2014 saw a number of small but notable changes. In the CONUS constellation, several new 30 KHz voice transponders appeared on 248.825, 249.375, 251.275, 251.325, 267.825, and 267.925; note that the first two of these are in the data portion of the band, and several do not appear in any standard bandplan of which I'm aware. In the PAC constellation, we have a new 30 KHz voice transponder on 258.450 and three new 6 KHz data transponders on what the bandplan says should be voice channels: 262.100, 262.150 and 262.200.

This section last update 2014-03-16

Frequency Heading Bandwidth Probable Satellite and GEO PositionNotes
243.8075SW58 KHzMilstar?spread spectrum; overlaps w/ 243.8195
243.8195SE58 KHzMilstar DFS-4 67.9W?spread spectrum from 243.7905-243.8485
243.915SE6 KHzCh 199 - CONUS: UFO5 99.4W
243.925SE6 KHzCh 200 - CONUS: UFO5 99.4W
243.935SE6 KHzCh 201 - CONUS: UFO5 99.4W
243.945SE6 KHzCh 202 - CONUS: UFO5 99.4W
243.955SE6 KHzCh 203 - CONUS: UFO5 99.4W
243.965SE6 KHzCh 204 - CONUS: UFO5 99.4W
243.975SE6 KHzCh 205 - CONUS: UFO5 99.4W
243.985SE6 KHzCh 206 - CONUS: UFO5 99.4W
243.995SW6 KHzCh 208 - PAC: UFO4 177.1Wslightly SE of 244.075
244.005SW6 KHzCh 210 - PAC: UFO4 177.1W
244.015SW6 KHzCh 212 - PAC: UFO4 177.1W
244.025SW6 KHzCh 213 - PAC: UFO4 177.1W
244.035SW6 KHzCh 214 - PAC: UFO4 177.1W
244.045SW6 KHzCh 215 - PAC: UFO4 177.1W
244.055SW6 KHzCh 216 - PAC: UFO4 177.1W
244.065SW6 KHzCh 217 - PAC: UFO4 177.1W
244.075SW6 KHzCh 218 - PAC: UFO8 173.3Eslightly SW of 243.995
244.085SW6 KHzCh 219 - PAC: UFO8 173.3E
244.095SW6 KHzCh 221 - PAC: UFO8 173.3E
244.105SW6 KHzCh 223 - PAC: UFO8 173.3E
244.115SW6 KHzCh 225 - PAC: UFO8 173.3E
244.125SW6 KHzCh 226 - PAC: UFO8 173.3E
244.135SW6 KHzCh 227 - PAC: UFO8 173.3E
244.145SW6 KHzCh 228 - PAC: UFO8 173.3E
244.155SW6 KHzCh 229 - ?shared w/UFO6; off air 20121109
244.155SE6 KHzCh 229 - CONUS: UFO6 105.5Wshared w/ ?
244.165SW6 KHzCh 230 - ?shared w/UFO6; off air 20121109
244.165SE6 KHzCh 230 - CONUS: UFO6 105.5Wshared w/ ?
244.175SW6 KHzCh 231 - ?shared w/UFO6; off air 20121109
244.175SE6 KHzCh 231 - CONUS: UFO6 105.5Wshared w/ ?
244.185SW6 KHzCh 232 - ?shared w/UFO6; off air 20121109
244.185SE6 KHzCh 232 - CONUS: UFO6 105.5Wshared w/ ?
244.195SW6 KHzCh 234 - ?shared w/UFO6; off air 20121109
244.195SE6 KHzCh 234 - CONUS: UFO6 105.5Wshared w/ ?
244.295SW6 KHzCh 236 - ?shared w/UFO6; off air 20121109
244.205SE6 KHzCh 236 - CONUS: UFO6 105.5Wshared w/ ?
244.215SW6 KHzCh 238 - ?shared w/UFO6; off air 20121109
244.215SE6 KHzCh 238 - CONUS: UFO6 105.5Wshared w/ ?
244.225SW6 KHzCh 239 - ?shared w/UFO6; off air 20121109
244.225SE6 KHzCh 239 - CONUS: UFO6 105.5Wshared w/ ?
248.825SE30 KhzNot in bandplanfirst noticed 20140314; stronger than UFO5/6
248.845SE6 KHzCh 129 - CONUS: UFO5 99.4W
248.855SE6 KHzCh 131 - CONUS: UFO5 99.4W
248.865SE6 KHzCh 132 - CONUS: UFO5 99.4W
248.875SE6 KHzCh 133 - CONUS: UFO5 99.4W
248.885SE6 KHzCh 134 - CONUS: UFO5 99.4W
248.895SE6 KHzCh 135 - CONUS: UFO5 99.4W
248.905SE6 KHzCh 137 - CONUS: UFO5 99.4W
248.915SE6 KHzCh 138 - CONUS: UFO5 99.4W
248.925SE6 KHzCh 139 - CONUS: UFO5 99.4W
248.935SE6 KHzCh 140 - CONUS: UFO5 99.4W
248.945SE6 KHzCh 141 - CONUS: UFO5 99.4W
248.955SE6 KHzCh 143 - CONUS: UFO5 99.4W
248.965SE6 KHzCh 144 - CONUS: UFO5 99.4W
248.975SW6 KHzCh 145 - PAC: UFO4 177.1Wslightly SE of 249.105
248.985SW6 KHzCh 146 - PAC: UFO4 177.1W
248.995SW6 KHzCh 147 - PAC: UFO4 177.1W
249.005SW6 KHzCh 149 - PAC: UFO4 177.1W
249.015SW6 KHzCh 150 - PAC: UFO4 177.1W
249.025SW6 KHzCh 151 - PAC: UFO4 177.1W
249.035SW6 KHzCh 152 - PAC: UFO4 177.1W
249.045SW6 KHzCh 153 - PAC: UFO4 177.1W
249.055SW6 KHzCh 155 - PAC: UFO4 177.1W
249.065SW6 KHzCh 156 - PAC: UFO4 177.1W
249.075SW6 KHzCh 157 - PAC: UFO4 177.1W
249.085SW6 KHzCh 158 - PAC: UFO4 177.1W
249.095SW6 KHzCh 159 - PAC: UFO4 177.1W
249.105SW6 KHzCh 161 - PAC: UFO8 173.3Eslightly SW of 248.975
249.115SW6 KHzCh 162 - PAC: UFO8 173.3E
249.125SW6 KHzCh 163 - PAC: UFO8 173.3E
249.135SW6 KHzCh 164 - PAC: UFO8 173.3E
249.145SW6 KHzCh 165 - PAC: UFO8 173.3E
249.155SW6 KHzCh 167 - PAC: UFO8 173.3E
249.165SW6 KHzCh 168 - PAC: UFO8 173.3E
249.175SW6 KHzCh 169 - PAC: UFO8 173.3E
249.185SW6 KHzCh 170 - PAC: UFO8 173.3E
249.195SW6 KHzCh 171 - PAC: UFO8 173.3E
249.205SW6 KHzCh 173 - PAC: UFO8 173.3E
249.215SW6 KHzCh 174 - PAC: UFO8 173.3E
249.225SW6 KHzCh 175 - PAC: UFO8 173.3E
249.235SE6 KHzCh 176 - CONUS: UFO6 105.5W
249.245SE6 KHzCh 177 - CONUS: UFO6 105.5W
249.255SE6 KHzCh 179 - CONUS: UFO6 105.5W
249.265SE6 KHzCh 180 - CONUS: UFO6 105.5W
249.275SE6 KHzCh 181 - CONUS: UFO6 105.5W
249.285SE6 KHzCh 182 - CONUS: UFO6 105.5W
249.295SE6 KHzCh 183 - CONUS: UFO6 105.5W
249.305SE6 KHzCh 185 - CONUS: UFO6 105.5W
249.315SE6 KHzCh 186 - CONUS: UFO6 105.5W
249.325SE6 KHzCh 187 - CONUS: UFO6 105.5W
249.335SE6 KHzCh 188 - CONUS: UFO6 105.5W
249.345SE6 KHzCh 189 - CONUS: UFO6 105.5W
249.355SE6 KHzCh 191 - CONUS: UFO6 105.5W
249.375SE30 KHzNot in bandplanfirst noticed 20140314; stronger than UFO5/6
249.600SW??narrow carrier
249.7205SE420 KHz?sidebands every 15.5 KHz; pos LEO/HEO
250.075SSW36 KHzSDS III-3 (USA-162) 143.9W
250.350SE?Ch 1 - CONUS: UFO5 99.4W?narrow carrier; off air 20140314
250.400SW?Ch 2 - PAC?data; off air 20130305
250.450SE30 KHz?Ch 3 - CONUS?normally distributed peaks spanning 30 KHz
250.550SW?Ch 5 - PAC: UFO8 173.3Enarrow carrier
250.650SE30 KHzCh 7 - CONUS: UFO6 105.5W
251.275SE30 KHznot in bandplan - CONUS ?first noticed 20140314
251.325SE30 KHznot in bandplan - CONUS ?first noticed 20140314
251.700SW30 KHz?not in bandplan - SDS?
251.850SE30 KHzCh 9 - CONUS: UFO5 99.4Woff air 20140314
251.950SW30 KHzCh 10 - PAC: UFO4: 177.1Wslightly SE of 252.050
252.050SW30 KHzCh 11 - PAC: UFO8: 173.3Eslightly SW of 251.950
252.150SW?Ch 12 - ?shared w/UFO6; off air 20121109; back on 20130305; narrow carrier
252.150SE30 KHzCh 12 - CONUS: UFO6 105.5Wshared w/ ?;off air 20140314
253.000SW?TACSAT4?LEO
253.262WSW280 KHz??peaks every 15.75 KHz; pos LEO/HEO
253.550SE30 KHzCh 13 - CONUS: UFO5 99.4W
253.650SW30 KHzCh 14 - PAC: UFO4 177.1W
253.750SW30 KHzCh 15 - PAC: UFO8 173.3Ewideband Asian b/c audio
253.850SE30 KHzCh 16 - CONUS: UFO6 105.5WPortuguese 20121019
254.075SW30 KHzon or near UFO4 177.1WUK channel; off air 20130305
254.100SE30 KHzCh 241 - CONUS ?first noticed 20140314
254.150SE30 KHzCh 192 - CONUS ?first noticed 20140314
254.150SW30 KHzon or near UFO4 177.1WUK channel; off air 20130305
255.250SE30 KHzCh 17 - CONUS: UFO5 99.4W
255.350SW30 KHzCh 18 - PAC: UFO4 177.1W
255.450SW30 KHzCh 19 - PAC: UFO8 173.3E
255.550SE30 KHzCh 20 - CONUS: UFO6 105.5WPortuguese 20121019
256.375WSW30 KHz??data; possible LEO/HEO
256.475SSW36 KHz?SDS III-3 (USA-162) 143.9Wdata
256.850SE30 KHzCh 21 - CONUS: UFO5 99.4W
256.950SW30 KHzCh 22 - PAC: UFO4: 177.1W
257.050SW30 KHzCh 23 - PAC: UFO8: 173.3E
257.150SE30 KHzCh 24 - CONUS: UFO6 105.5W
257.550SE30 KHzUK Channelfirst noticed 20140314
257.550SW30 KHzon or near UFO4 177.1WUK channel; off air 20130305
258.350SE30 KHzCh 25 - CONUS: UFO5 99.4W
258.450SW30 KHzCh 26 - PAC: UFO4? 177.1Wfirst noticed 20140314
258.550SW30 KHzCh 27 - PAC: UFO8 173.3E
258.650SW30 KHzCh 28 - ?shared w/UFO6; off air 20140314
258.650SE30 KHzCh 28 - CONUS: UFO6 105.5Wshared w/ ?
260.375SE30 KHzCh 46 - CONUS: UFO5 99.4W
260.425SW30 KHzCh 48 - PAC: UFO8 173.3E
260.475SE30 KHzCh 50 - CONUS: UFO5 99.4W
260.525SW30 KHzCh 52 - PAC: UFO8 173.3E
260.575SW30 KHzCh 54 - PAC UFO4: 177.1W
260.625SW30 KHzCh 56 - ?shared w/UFO6;Russian/Altai phone audio; off air 20121023
260.625SE30 KHzCh 56 - CONUS: UFO6 105.5Wshared w/ ?; Portuguese 20121019
260.675SW30 KHzCh 58 - PAC: UFO4 177.1W
260.725SW30 KHzCh 60 - ?shared w/UFO6; off air 20121109
260.725SE30 KHzCh 60 - CONUS: UFO6 105.5Wshared w/ ?; Portuguese 20121019
261.575SE30 KHzCh 71 - CONUS: UFO5 99.4W
261.625SW30 KHzCh 73 - PAC: UFO8 173.3E
261.675SE30 KHzCh 75 - CONUS: UFO5 99.4W
261.725SW30 KHzCh 77 - PAC: UFO8 173.3E
261.775SE30 KHzCh 79 - CONUS: UFO5 99.4W
261.825SW30 KHzCh 81 - PAC: UFO8 173.3E
261.875SE30 KHzCh 83 - CONUS: UFO5 99.4W
261.925SW30 KHzCh 85 - PAC: UFO8 173.3E
262.075SW30 KHzCh 88 - PAC: UFO4 177.1W
262.100SW6 KHzCh 89 - PAC: UFO4? 177.1W30KHz in bandplan!; first noticed 20140314
262.125SW30 KHzCh 90 - ?shared w/UFO6; off air 20121109
262.125SE30 KHzCh 90 - CONUS: UFO6 105.5Wshared w/ ?
262.150SW6 KHzCh 91 - PAC: UFO4? 177.1W30KHz in bandplan!; first noticed 20140314
262.175SW30 KHzCh 92 - PAC: UFO4 177.1W
262.200SW6 KHzCh 93 - PAC: UFO4? 177.1W30KHz in bandplan!; first noticed 20140314
262.225SW30 KHzCh 94 - ?shared w/UFO6; off air 20121109
262.225SE30 KHzCh 94 - CONUS: UFO6 105.5Wshared w/ ?
262.275SW30 KHzCh 96 - PAC: UFO4 177.1W
262.325SW30 KHzCh 98 - ?shared w/UFO6; off air 20121109
262.325SE30 KHzCh 98 - CONUS: UFO6 105.5Wshared w/ ?
262.375SW30 KHzCh 100 - PAC: UFO4 177.1W
262.425SW30 KHzCh 102 - ?shared w/UFO6; off air 20121109
262.425SE30 KHzCh 102 - CONUS: UFO6 105.5Wshared w/ ?
263.225SSW36 KHz?SDS III-3 F3 143.8Wdata
263.575SE30 KHzCh 109 - CONUS: UFO5 99.4W
263.625SW30 KHzCh 111 - PAC: UFO8 173.3EOp Deep Freeze traffic 20121022
263.675SE30 KHzCh 113 - CONUS: UFO5 99.4W
263.725SW30 KHzCh 115 - PAC: UFO8 173.3E
263.775SW30 KHzCh 117 - PAC: UFO4? 177.1W?on air 20130305
263.825SW30 KHzCh 119 - ?shared w/UFO6; off air 20121109
263.825SE30 KHzCh 119 - CONUS: UFO6 105.5Wshared w/ ?
263.875SW30 KHzCh 121 - PAC UFO4 177.1W
263.925SW30 KHzCh 123 - ?shared w/UFO6; off air 20121109
263.925SE30 KHzCh 123 - CONUS: UFO6 105.5Wshared w/ ?
265.250SE30 KHzCh 29 - CONUS: UFO5 99.4Wdata; off air 20130305; back on air 20140314
265.350SW30 KHzCh 30 - PAC: UFO4 177.1W
265.450SW30 KHzCh 31 - PAC: UFO8 173.3E
265.550SW30 KHzCh 32 - ?shared w/UFO6; off air 20121109
265.550SE30 KHzCh 32 - CONUS: UFO6 105.5Wshared w/ ?
266.750SE30 KHzCh 33 - CONUS: UFO5 99.4W
266.850SW30 KHzCh 34 - PAC: UFO4 177.1WRussian/Altai? phone audio 20121021 (edges of passband)
266.950SW30 KHzCh 35 - PAC: UFO8 173.3ERussian/Altai? phone audio 20121021 (edges of passband)
267.050SW30 KHzCh 36 - ?shared w/UFO6; off air 20121109
267.050SE30 KHzCh 36 - CONUS: UFO6 105.5Wshared w/ ?
267.550SSW38 KHz?SDS III-3 (US162) 143.8Wdata
267.825SE30 KHznot in bandplan - CONUS ?first noticed 20140314
267.925SE30 KHznot in bandplan - CONUS ?first noticed 20140314; Spanish lang broadcast
267.925SW30 KHznot in bandplan - slightly SE of UFO4?off air 20130305
268.150SE30 KHzCh 37 - CONUS: UFO5 99.4W
268.250SW30 KHzCh 38 - PAC: UFO4 177.1W
268.350SW30 KHzCh 39 - PAC: UFO8 173.3E
268.450SE30 KHzCh 40 - CONUS: UFO6 105.5WSpanish lang broadcast
269.650SE30 KHzCh 41 - CONUS: UFO5 99.4W
269.750SW30 KHzCh 42 - PAC: UFO4 177.1WAsian b/c audio 20121020 (269.747)
269.850SW30 KHzCh 43 - PAC: UFO8 173.3E
269.950SE30 KHzCh 44 - CONUS: UFO6 105.5W

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