Signals From Above...

I recently had an interesting afternoon up on a local high spot, investigating and monitoring the many satellites, mainly military, that operate in the band 240-270MHz.

These satellites normally have a transponders supporting a number of different frequency payloads, including UHF / S & X Band. Its worth noting that all these satellites are geo-stationary, operating in a fixed position above the equator.

Below is a screenshot from the traces I took today of satellites operating in the UHF band.

This screenshot above covers a number of different satellites, illustrating the different transponder outputs, signal bandwidths and modulation types. The signals illustrated above have been identified as the following:

243.625  -  ComSatBW-2      38KHz Channel  -  Operating at 13.2 East

243.785  -  MilSat 2-3            50KHz Channel  -  Operating at 30.0 East

243.8225 - Milsat 1                50KHz Channel  -  Operating at 39.1 West

243.995 - US UFO F2            8x 6KHz Channels  -  Operating at 28.3 East

244.075 - US UFO F7            8x 6KHz Channels  -  Operating at 23.3 West

244.185 - US FltSatCom F8   5x 6KHz Channels  -  Operating at 15.1 West

The next screenshot below is a slightly wider panoramic display, showing around 8MHz of sprectrum in the upper part of the 240-270MHz band. This shows some good traces for the following satellites:

269.750  -  UFO F2  -  34KHz Channel

268.675  -  SDS3-F2 - 25KHz Channel

265.350  -  UFO F2  -  34KHz Channel

268.000  -  Sircal 1b  - 5x 34KHz Channels

A few notes on my monitoring system setup. In order to capture the above traces, I used the following kit:

AirSpy SDR Receiver
SDR# Software
RFBay LNA-1000 (10-1000MHz 30db Amplifier)
Trivec 2030 UHF MilSat Antenna

Acknowledgements:

Many thanks to the following websites for their supporting content and details:

http://www.uhf-satcom.com/

http://www.satellitenwelt.de/uhfmilsat.htm

The Russian Navy on 17M Amateur Band

Back online after a rather long break..!

Just having a listen around on the bands today, and it appears that the Russian Navy are busy again - this time in the 17M Amateur band.

On / around 18.106MHz I received nearly 30 messages in under an hour. All traffic was the signal NATO designater T-600 [Bee] also known as CIS 36-50.

A very useful for tool for analyzing this signal is a program developed by Ian Wraith, called the
Rivet decoder. Below a screenshot of some of the traffic received, together with a link about T-600 / CIS 36-50

Further Info Here.

Stay safe - Good DX.

Another Signal Looking For Ident - Possibly CIS-12 (Fire)

Hi All,

Another post, this time for a signal which, having had a scan around the internet and good read up, I may have identified, but would welcome comments / confirmation.

The signal is another complex signal / what appears to he a 12 channel / multi-channel PSK system. This was received on the 27th June around 2040 UTC, on 11120KHz. An SDR-IQ receiver with SDR-Radio.com software was used. Below is the waterfall / sonograph trace together with an audio file.

With my limited analysis - I think this signal may be CIS-12 (Fire), apart from the obvious 12 channels it also  appears to have the signatory carrier / tone signal just on the upper side of the signal.

Any comments, suggestions or confirmation of signal / mode would be welcomed......

Many Thanks - Good DX !

                                                                 Audio Here

Two More UNID Signals

Been away for a while, but back on the bands again. A recent evening search found the following two signals which I'm trying to identify. Any clues or pointers to what these signals are would be gratefully received.

First signal I think is a scrambled voice link, but again any ident would be good.

Audio File

Second signal I think sounds like a composite PSK signal ?

Audio File

Many Thanks For Any Info - Good DX / Good Searching...

Welcome To 2182DX - A First Post !

Hi !  Happy New Year to all, thanks for viewing my blog.

Firstly an introduction to this page. This page is my outlet for publishing updates, reports and general findings and any questions I may have from my HF / Shortwave listening. This HF listening covers HF utility, shortwave broadcasting, amateur bands & civil/military air-band stations.

So for my first report, I have details two signals which were found a couple of months back, both of which I'm trying to identify. Both were relatively wideband, one was of short duration burst type, the other a continuous transmission.

Details as follows:

First Signal, received at 2016z 16-10-2011, centred on 9000KHz USB. Signal bandwidth around 15KHz, duration was around 15s, signal level +15dbm above noise floor. (Attached JPG & MP3)

   

Audio File

Second signal, received at 1957z 16-10-2011, centred on 9070KHz. Signal bandwidth around

20KHz, continous transmission. Signal level around +35dbm above noise floor. (Attached JPG- MP3)

Audio File

Any suggestions or clues as to who or what these signals may be would be greatly appreciated...!

Until next time - thanks for looking me up !

73 - Good DX & Be Safe...