Category Archives: hamsat

Made my first satellite QSO

As well as flying a high altitude balloon another of my aims this year was to finally make a satellite QSO. Pleased to say last night I finally achieved it!

Last month Abdel Mesbah M0NPT chairman of the Hucknall Rolls-Royce ARC came to South Kesteven ARS to give an informative talk on operating amateur radio satellites. Abdel was the first UK operator to receive the AMSAT-UK 73 on 73 award for making 73 confirmed contacts via the FUNCube satellite AO-73.

Abdel explained all the current active satellites, how to work through them and gave hints and described techniques for achieving success on this more challenging mode of operation.

Spurred on I opted to target the SO-50 satellite which until very recently this was the only satellite carrying a FM transponder. The satellite receives on 145.850 MHz and retransmits them on 436.800 MHz (+/- 10 kHz Doppler shift). Operation requires the use of CTCSS (PL) tones of 74.4 Hz which starts a 10 minute timer and then a 67 Hz tone used for the contact. More details of how to operate and a video are on the AMSAT-UK website

I initially tried using just a suitably programmed Baofeng UV-5R with a NA771 whip and could clearly hear the downlink on higher passes, I called a few times with no luck.

I hadn’t monitored SO-50 much before and sadly it seems to suffer from very poor operating, with stations calling over contacts in progress, or stations continually calling CQ CQ seemingly oblivious to any reply and those that just keep calling “hola hola hola” for whatever bizarre reason! I would be lucky to get through the QRM with just the whip so I needed a better antenna.

Despite being extremely busy at the National Hamfest last weekend I did manage to get hold of a dual band Yagi that was reasonably lightweight for hand held use and capable of being easily dismantled for transporting. (The Moonraker YG27-35 Dual Band) it has a single feed point and two adjustable gamma match sliders and was easy to adjust using my analyser.

It has a single feed and I tried it with the Baofeng and reception of the downlink was excellent, again on a couple of passes I tried answering calls with no success.

Last night I decided to try again but with the FT-857D set at 10W output. I put it on a small workbench in the garden and powered it from my portable SLA battery. I ran split operation with the 2m Tx VFO set at 145.850MHz with 67Hz CTCSS, the 70cm Rx VFO set at 436.800Mhz I was able to adjusted it down in 5kHz steps during the pass. I got the wife to take a picture while I was operating.

As I started to hear the downlink I heard Abdel M0NPT calling and answered him, I was shocked when he came back and we exchanging details – that was it I had made my first QSO via an amateur radio satellite! Then amazingly other stations started calling me and I was able to also work DO2SYD.

I did manage to record it on a small dictaphone (did have a bit of a brain fade with my callsign at one point!)

I could get hooked on this…  There is also the new LilacSat-2 (CAS-3H) satellite with a FM transponder to try to work!So much to do, so little time…

More SSTV from the ISS

Like many others around the globe I spent yesterday attempting to receive and decode the SSTV transmissions being broadcast from the International Space Station by the Russian Cosmonauts.

The SSTV activity had been due to last three days starting on Saturday but commencement was delayed by the NASA space walk.

Receiving the signal and decoding is relatively straightforward due to relatively high power used (around 25W) however getting a perfect image is a challenge and dependant on a number of factors.

  • The timing of the overhead pass. Due to the time taken to transmit the image and the three minute delay between each image it is possible to only be in reception range for the end of one image and the start of the next. 
  • The ISS is moving quickly and so the transmission suffers noticeable Doppler shift. FM is more immune to the effect but for optimal performance adjustment of the tuned frequency is required especially on high elevation passes (more information).
  • The ISS moves position, both in direction and elevation as it moves across the sky and will show up the peaks and troughs in a static antennas radiation pattern. This leads to bands of noise when the signal level falls. The use of a rotatable (and if possible tiltable) antenna (or even an handheld one) is the dirigour mode of operating satellites (and the ISS) for serious enthusiasts. 
  • Noise and local interference will also obviously affect the image.
Mission Control

I opted a two pronged approach, the Yaesu FT857D connected to my rotatable four element YAGI which is mounted horizontally for SSB and the old TRIO/KENWOOD TR9000 was connected to the X50 dual-band collinear mounted vertically.

I had two copies of the MMSSTV program running on separate laptops The TR9000 was left running largely unattended tuned to 145.800MHz, while the FT857D was tweaked to the optimum frequency while the YAGI antenna was rotated to the correct azimuth during the pass.

All adjustments were done manually and I use the Orbitron program for prediction and under the Rotor/Radio tab the frequency and azimuth are shown and updated during the pass (as can be seen in the screen show below)

I missed the first low elevation at 11:07UTC, but was able to monitor and decode images on all the remaining passes during the day, with some excellent results, the images show the full images decodes on both radio set ups as a comparison.

FT857D – Yagi

TR9000 – Collinear

FT857D – Yagi

TR9000 – Collinear

FT857D – Yagi

TR9000 – Collinear

FT857D – Yagi

TR9000 – Collinear

FT857D – Yagi

TR9000 – Collinear

I was especially pleased when one of my best images was featured on the Amsat-UK and the Southgate Amateur Radio News websites.

What was slightly worrying and it also happened during the last SSTV activities were some operators transmitting on the downlink frequency even during a pass, what sounded like someone keying up was responsible for the single noise line on another perfect image. I even received an unexpected SSTV image, complete with a call sign while the system was waiting for the next pass. I won’t publish it here as everyone makes mistakes.

The experiments are continuing today but I am in work so will just leave an automated set up running on the collinear.

Judging by the messages on social media these SSTV activities seem to have captured the imagination of a lot of operators and several members of my local club South Kesteven Amateur Radio Society (SKARS) had their first go with some excellent results and are hooked! The images can seen on the SKARS Facebook page

Long may the activities continue, hopefully started to transmit some live images from space.

Back In The Shack – Reception report VO-52

Things are hopefully get back to some form of normality here after a difficult few weeks.

During my downtime I missed the news that VO-52 HAMSAT had fallen silent on the 28th February a week after my last post. But good news the Dutch built CW/SSB transponder  was reactivated yesterday so last night and this morning I monitored a couple of passes. The transponder was certainly busy and I got some nice captured IQ files to analyse later.

Using just the loft mounted discone I monitored quite a little QSO between G7SVF and I8CVS this morning which I managed to capture using the audio recorder.

VO-52 (15-Mar-2012-0823) by nerdsville

The discone It isn’t the best antenna for satellite work, especially with the FUNCube dongle as it’s wideband characteristics heavy overload the front end, but it is nice capture all the same, even if it made me slight late this morning and so got caught in the school run traffic.

I did a Google search on the call signs and discovered I8CVS is Domenico Marini from Napoli Italy. Dom appears to be a well known expert in amateur satellite operation.  On that page is a picture of Dom in 2003 next to an impressive antenna array which appears to be sited on top a high rise building (oh the envy!)

While my own set up is much more modest. I have done a little tinkering, building a small UHF Yagi out of some metal coat hangers but have yet to test it in anger. I have also become a little more familiar with my FUNCube setup. I use the application and having updated to a much later beta version have had much more success. There were some issues that involved the swapping the I and Q signal on early versions but these appear to have now been corrected.

After listening to the ICQ Podcast I have been monitoring a few propagation beacons (GB3VHF and GB3BUX) (I will post more on this later) and using those beacons have got the frequency calibration more or less spot on now. I have also discovered that the Doppler Invert option needed setting so now SDR-Radio more or less correct perfectly as the satellites passes (still occasionally needs some manual interaction)

I really must make a real effort to get a licence and become less passive in this hobby, just not sure how I am going to afford an all-modes transceiver mind! 

Video of VO52(HAMSAT)

Due to work and family commitments and the currently inconvenient timing of the passes I really haven’t had a serious attempt at receiving any of the downlinks from the numerous Cubesats launched on the Vega rocket back on Monday February 13.

I have managed to get some faint transmissions from what I believe is Masat-1 which has now been officially designated MagyarSat-OSCAR-72 (MO-72) I have also seen a number of other traces on the waterfall display of the sdr  (using the FUNCube dongle) They are in the correct frequency range and appear and disappear as the cluster of cubesats were predicted as passing overhead.

I have managed to make a video of  a pass of the SSB VO52(HAMSAT) downlink being received by the FCD this morning using just the antenna in the loft.

Operating a camera in one hand and trying to track the signal isn’t that easy, but you get the idea!

I have got a chance this weekend to have a proper attempt at the Vega cubesats.