11th birthday of ham radio satellite SO-50

Saudisat SO-50

Saudisat SO-50

December 20, 2013 will be the 11th birthday of the amateur radio satellite SO-50.

Now known as SO-50, Saudisat 1C is a Saudi Arabian satellite about 25 cm cubed that was launched by a Dnepr rocket from Baikonur in Kazakhstan at 17:00 UT on December 20, 2002. SO-50 features a “Mode J” FM amateur repeater operating on a 145.850 MHz uplink and a 436.795 MHz (+/- 9 kHz Doppler shift) downlink.

“Most hams already own the necessary equipment to work SO-50,” reports Clint Bradford, K6LCS, who maintains a Web site work-sat.com devoted to working amateur satellites with minimal equipment.

“It is preferable to work SO-50 in true, full-duplex mode – so you can hear the downlink as you transmit. This means – for most – using a second radio or the Kenwood TH-D72A and its true full-duplex capability. The new Puxing PX-UV973 is currently being tested in this mode, too, to see how it works on the satellites.”

SO-50’s repeater is available to amateurs worldwide, and it uses a 67.0 Hz CTCSS (PL) tone on the uplink. SO-50 also has a 10 minute timer that must be armed before use. If you know the satellite is there – but there is nothing heard – you may need to shoot it a CTCSS (PL) tone of 74.4 Hz to turn it ON!

The repeater consists of a miniature VHF receiver with sensitivity of -124 dBm, with an IF bandwidth of 15 kHz. The receive antenna is a 1/4 wave vertical mounted in the top corner of the spacecraft. Its UHF transmitter is a mere 250 mW, and downlink antenna is a 1/4 wave mounted in the bottom corner of the spacecraft and canted at 45 degrees inward.

“Hams just with Technician licenses [or UK Foundation] can work the satellite,” Clint continues. “We are talking about weak signals from 500 miles away – so improving both your TX and RX antennas is critical for success on this satellite.” Plans for making tape measure beams and other inexpensive, high-gain antennas is also on his Web site.

“Do not forget to accommodate for the Doppler shift (+/-9 kHz) on the 436 MHz receive side.”

Complete details – including frequency chart and sources for knowing when the satellite will be over your area, are also on Clint’s Web site.

Work-Sat http://www.work-sat.com/

Watch a video of Simon 2E0HTS working via SO-50 at
http://amsat-uk.org/beginners/how-to-work-a-fm-satellite/

Satellite Tracking http://amsat-uk.org/beginners/satellite-tracking/

SO-50 on Baofeng UV5R

David Mercado KK4MND has produced a video showing how easy it is to receive the amateur radio satellite SO-50.

This video demonstrates how to communicate via Amateur Ham Radio Satellite using an inexpensive £30 Baofeng UV5R Dual Band Radio and MFJ dual band antenna from Amazon. Among the stations heard are Hector Martinez CO6CBF, Dave Beumer W0DHB and James Bayne KI4SIY.


SO50 frequencies
Uplink – 145.850 MHz with 67 HZ CTCSS
(initial 74.4 Hz CTCSS tone required if satellite has not already been activated)
Downlink – 436.800 MHz

SO-50 article by Howard Long G6LVB
http://www.g6lvb.com/Articles/operatingSO50.htm

SO-50
http://amsat-uk.org/2012/01/30/working-the-fm-sat-so-50/

Credit Southgate ARC

AMSAT Field Day 2013

Saudisat SO-50

Saudisat SO-50

The AMSAT-NA site reports on satellite activity for this years ARRL Field Day which takes place June 22-23.

Every year AMSAT promotes a satellite version of Field Day during the ARRL annual operating event which is held on the 4th weekend in June. This year Field Day will take place from 1800 UTC on Saturday June 22, 2013 through 2100 UTC on Sunday June 23, 2013.

SaudiSat-Oscar-50 will be the only operational FM transponder satellite this year. If you are considering only FM voice operating for your AMSAT Field Day focus the single uplink/downlink channel will be extremely challenging. As in prior years, this intense congestion on FM LEO satellites drives the limitation in the rules allowing their use to one-QSO-per-FM-satellite. This includes the International Space Station. You will be allowed one QSO if the ISS is operating Voice. You will also be allowed one digital QSO with the ISS or any other digital, non-store-and-forward, packet satellite (if operational).

If you have worked the satellites on Field Day in recent years, you may have noticed a lot of good contacts can be made on the linear transponder satellites including VO-52, FO-29, and AO-7. During Field Day the transponders come alive like 20 meters on a weekend. The transponders on these satellites will support multiple simultaneous SSB or CW contacts.

The AMSAT Field Day 2013 event is open to all Amateur Radio operators. Amateurs are to use the exchange as specified in ARRL rules for Field Day. The AMSAT competition is to encourage the use of all amateur satellites, both analog and digital.

For the complete listing of the AMSAT Field Day Rules please refer to the documents posted on-line at:

http://www.amsatnet.com/2013fd.docx
http://www.amsatnet.com/2013fd.pdf

[We thank AMSAT Director Contests and Awards, Bruce Paige, KK5DO for the above information]

Source: AMSAT-NA K9JKM

AMSAT-LU to launch amateur radio FM repeater to an altitude of 30 km

AMSAT-LU SSTV and GPS Payload

View of communications experiment: Below is the plate of the repeater. Top left is the SSTV camera and top right is the GPS receiver module. Image credit LU7AA

On Saturday, March 23 at 1400 UT AMSAT-LU plan to launch a High Altitude Balloon (HAB) carrying a 435.950/145.950 MHz FM repeater, a SSTV transmitter on 145.850 MHz and an APRS transmitter on 144.930 MHz.

The 145.850 MHz SSTV ROBOT-36 mode images will be transmitted in real time showing the view from the balloon. The images can be displayed by using free software such as MMSSTV.

Since 145.850 MHz is the input frequency for the amateur radio satellite SO-50, part of the experiment will be a link between the balloon and the satellite with SO-50 retransmitting the SSTV images on 436.7950 MHz over a far wider area.

At an altitude of 30 km the FM repeater, which uses a 123 Hz CTCSS tone, could have a range of up to 750 km.

AMSAT-LU have issued the following announcement:

Continue reading

More Cubans Active on Ham Radio Satellites

Raydel Espinet CM2ESP - 640

Raydel Espinet CM2ESP

On the AMSAT bulletin board Raydel Espinet CM2ESP reports that more Cuban radio amateurs have become active on the satellites. He writes:

As many of you should already know, now we have two new Cuban Amateur Operators on FM Satellites. Recently CO7WT and CM2XN have finally achieve their first QSO on SO-50 Satellite. This may look simple, but for a Cuban Ham this is a great success, after many weeks of antenna building, equipment adjustments and learning, this two fellow hams enjoy of the amazing opportunity of make a QSO on a FM Transponder Satellite. They know there is a lot more of operating skills to learn and they are very happy to do so.

Continue reading

Working the FM-Sat SO-50

Saudisat SO-50

Saudisat SO-50

Simon 2E0HTS has released a video that shows him making contacts via the amateur radio satellite SO-50.

This satellite carries an FM transponder that receives signals on 145.850 MHz and retransmits them on 436.795 MHz (+/- 10 kHz Doppler shift). Operation is a little more complex that some other satellites since the transponder needs to initially be activated by a CTCSS (PL) tone of 74.4 Hz which starts a 10 minute timer and then a 67 Hz tone is used for the contact.

The order of operation is: (allow for Doppler as necessary):
1) Transmit on 145.850 MHz with a tone of 74.4 Hz to arm the 10 minute timer on board the spacecraft.
2) Now transmit on 145.850 MHz (FM Voice) using 67.0 Hz within the 10 minute window.
3) Sending the 74.4 Hz tone again within the 10 minute window will reset the 10 minute timer.

You can set the memory channels in your handheld as follows:
Ch     TX              RX            CTCSS
1     145.850     Timer Reset 74.4 Hz
2     145.850     436.805       67 Hz
3     145.850     436.800       67 Hz
4     145.850     436.795       67 Hz
5     145.850     436.790       67 Hz
6     145.850     436.785       67 Hz
At the start of the pass tune to 436.805 and then decrease the frequency during the 10+ minute pass.

Watch Simon 2E0HTS working CT2GOY, F0FVK, SP5XSD & EA6SW/portable 6, via SAUDISAT 1C SO-50

Simon 2E0HTS Ham Radio Operator Blog http://www.hamradiooperator.blogspot.com/

You can read Howard G6LVB’s SO-50 article at http://www.g6lvb.com/Articles/operatingSO50.htm

SO-50 http://www.amsat.org/amsat-new/satellites/satInfo.php?satID=4

N2YO Real Time Satellite Tracking http://www.n2yo.com/

Satscape Satellite Tracking Software http://www.satscape.info/home/?q=node/2

John Heath G7HIA’s article  ‘Getting started on amateur radio satellites’ can be downloaded from http://www.uk.amsat.org/267