Working Satellite SO-50

One aspect of amateur radio that I am enjoying lately is working the FM satellite SO-50. To do so I use my Boafeng GT-3TP dual band hand held and an Elk log periodic antenna that I have mounted on a camera tripod.

My basic satellite communications setup.

SO-50 carries several experiments, including a mode J FM amateur repeater experiment operating on 145.850 MHz uplink and 436.795 MHz downlink. The repeater is available to amateurs worldwide as power permits, using a 67.0 Hertz PL tone on the uplink, for on-demand activation. The repeater consists of a miniature VHF receiver with sensitivity of -124dBm, having an IF bandwidth of 15 KHz. The receive antenna is a 1/4 wave vertical mounted in the top corner of the spacecraft. The receive audio is filtered and conditioned then gated in the control electronics prior to feeding it to the 250mW UHF transmitter. The downlink antenna is a 1/4 wave mounted in the bottom corner of the spacecraft and canted at 45 degrees inward.

The Elk was loaned to me by Wal, VK4CBW, an avid satellite fan who lives down the road from me. The antenna is basically a held-held job but I do find it gets a bit heavy after a while, hence the tripod.

Today SO-50 was within range at 4.56pm, so I put out a call and was answered by Roy, VK4ZQ, from Nundah in Queensland. And although Roy isn’t that far from me, the satellite is. The apogee height is 665km, which means at its furthermost distance from the earth, it is 665km away. Not bad for a two-way FM contact.


Building a mounting board for hand-held radios


I have long wanted to build something to mount my hand-held radios on instead of having them balancing on my workbench shelf, where they are easily knocked over. I have seen others keeping them mounted in their chargers, but after consulting with the amateur radio community decided this wasn’t such a good idea.

So it was back to my workshop to construct a simple bracket-like mounting board out of wood that I happened to have among my store of timber. I found I had a nice piece of pine as well as a sheet of 6.4mm ply wood that would do just fine. So it was out with my router, to which I inserted a 6.4mm bit to cut a dado. The ply would fit nicely into this, after glue had been applied, of course.

Once that was done I applied some oak refinishing oil, which added a nice touch to the finished product.


There is more than enough room for four radios.

All my radios have the belt clips installed, which is handy as they can now clip nicely and securely to the board.

Working the satellites

I always wanted to work the satellites as there seems to be something mystical about them. They aren’t called ‘the final frontier’ for nothing.

After talking to Wallace, VK4CBW, it became apparent that this would be quite feasible with a dual-band hand held transceiver and some satellite-tracking software on my computer.

My Boafeng GT-3TP would do fine so I downloaded and installed gpredict into my Surface Pro 4.

I proceeded to monitor my satellite of choice, SO-50, which I chose because it is an FM satellite. Wallace helped program in the receive and send frequencies into my hand-held; receive frequencies starting at 436.805 and progressing down at 5khz intervals to 436.780 would be needed to take the Doppler effect into account. Transmit frequency remains at 145.850.

screenshot-1   As the satellite came within range I headed outside and turned on my hand-held, with the squelch turned right down. Pointing the rubber-duckie antenna towards the ground, I put out a call .. and listened. Turning this way and that, I repeated the call until I heard Wallace reply.

I had made my first contact. The interesting thing about this was that his shack is only some 300m down the road from my shack, but we were communicating via a satellite in space. The pass only lasted around eight minutes or so; brevity is the name of the game here.

My next attempt would be with an Elk antenna, a specially-designed four-element log periodic antenna that Wallace will lend me.

Activating Mt Ainslie VK1/AC-040

Although I have already activated Mt Ainslie, I decided to walk up there again on Sunday 5 July as Andrew, VK1NAM would be activating VK1/AC-044 Boboyan Ranges, which is a four-pointer.

My plan was to do a summit to summit contact on 2m FM.

The day dawned cold and wintery, and for Canberra that means foggy too. So it was on with the cold weather gear, including beanie and gloves. I also packed my backpack with my Elecraft KX1, Buddistick antenna, tripod, coax and headphones. Seeing I was up there I would get onto CW as well.

The walk from my city apartment was via the Australian War Memorial and up the pathway to the summit from the Remembrance Nature Park at rear of this world class museum.

The walk would be 4.5 km return, with some sections being quite steep. The walk is called the Kakoda Track. The path is good and the trees along the way are fantastic, especially when shrouded in mist.

A winter wonderland on the way up.

A winter wonderland on the way up.

At the top I made contact with Andrew on FM and bagged another S2S point. Then I worked VK1VIC and VK1GVC, also on 2m FM. Time now to set up the CW station.

While walking along the summit to find a good location to erect the antenna, I came across Al, VK1RX, who had erected a wonderful homebrew 10m two element yagi. He was well into working the USA as part of the 6m and 10m challenge.

Al, VK1RX in the thick of 10m action.

Al, VK1RX in the thick of 10m action.

Once I was organised, I put out a spot and began calling CQ. It wasn’t long before the calls began coming in. I worked VK3PF, VK3AFW, VK2IO, VK2AOH and VK3HRA in quick succession. I was delighted. As I was only using six internal AA alkaline batteries, I was only putting out 1w, so this was well and truly a QRP activation.

That being the end of the activation, I packed up and headed back down the mountain. My SOTA scores are now:
Activator’s Log: 8 points
Chaser’s Log: 25 points
Summit to Summit: 20 points.

2014 Winter UHF/VHF Field Day

This weekend I packed up my portable gear, checked off my check list and headed out to the summit of Mt Coot-tha (grid square QG62LM) to participate in the annual Winter VHF/UHF Field Day.

My intention was not to chase any of the awards but merely to try out my new portable station that consists of an FT-817, and a 2m quarter wave ground plane antenna. The rig would be powered by a 2 a/h battery.

I found an unoccupied BBQ area, parked the car and set up my station. I would be concentrating on working SSB on the 2m band only. Power output would be 5 Watts.


My gear set up on the BBQ bench.

My gear set up on the BBQ bench. Note the antenna on a short pole.

I also had with me an Wouxun 2m/70cm hand held and a Yaesu FT-250 hand held (both FM units) just in case.

I spent two hours operating and made 11 contacts, so it was a case of mission accomplished.

The battery did well; to start with there was just on 13v and on completing there was 11.86v.

The battery did well; to start with there was just on 13v and on completing there was 11.86v.

Next time I will take along an antenna that will allow me to work the 70cm and 6m bands as well.

Thinking about C4FM

I have noticed that activity on the HF bands has been very poor over the last few months. So much so that I hear absolutely nothing on 80m and minimal DX on the other bands.

At first I suspected my antenna, which is a long wire. But I do get good reports from DX stations that I am able to work. Then I started noticing reports about low solar activity. I came across an article entitled entitled Cooling Kills: Governments Must Shift to Cold Preparation by TOM HARRIS and DR. MADHAV KHANDEKAR:

Of particular concern are the warnings from solar scientists that over the next three decades, we are headed toward significant global cooling as the sun weakens into a grand minimum. The last time the sun was as weak as solar experts predict will occur starting after 2030, the Earth was in a particularly cold phase of the Little Ice Age that lasted from about 1350-1850, a period when there was great misery around the world.
Tom Harris is Executive Director of the International Climate Science Coalition. Dr. Madhav Khandekar is a former Research Scientist with Environment Canada.

This got me thinking. If their predictions are correct, we can expect reduced HF activity. However, I have also noticed that VHF/UHF FM activity seems to perform okay. This, together with the notion that technology is fast evolving, I think I will look deeper into C4FM technology. This is basically a digital FM mode that allows for the transmission of voice as well as date communications, using commercially available equipment. In the amateur radio domain, Yeasu have just launched a range of transceivers that I plan to purchase, once I have sold off my HF gear to make space on my workbench.

Watch this space.

2013 in review

The stats helper monkeys prepared a 2013 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 8,600 times in 2013. If it were a concert at Sydney Opera House, it would take about 3 sold-out performances for that many people to see it.

Click here to see the complete report.