Your feedback, part 3

Yesterday’s newsletter generated two emails. The first one was more of a general observation, while the second one was a satellite related question.

“Ha, I’ve got you – the purpose of your GreenCube tutorial is to sell me a radio!”

Quite frankly, I thought that was obvious. If it isn’t: yes, since recently, I run a ‘micro radio dealership’ and I would love to sell you a radio. I mean, if that is not the most obvious thing ever, than I am not doing my job properly.

Now to the question: “Can I operate the satellite from the comfort of my home? I am not an outdoors person.”

Answer to that one is simple. Yes, if you live on a rural property, have no neighbours and have a clear view of the horizon. All you need to do is to put your antenna in your backyard, on an azimuth-elevation rotor (like Yaesu G-5500), run a length of low loss coax to the shack and you will never again have to leave that comfy chair. Unfortunately for a majority of urban amateurs, this is only a dream. Even if you are lucky to have some view, the man made interference in urban environments is simply unbearable, even on 70cm. The noise level is so high that a satellite signal will be buried deep underneath. You won’t hear or decode a thing.

But the moment you set yourself up in a park, or local hilltop, or at an ocean cliff, or lighthouse – you will be amazed how loud the GreenCube signal is. It literally screams out of the speaker!

Of course, the outdoors operation will push you a bit and some days are more challenging than others. Sun, rain, wind, snakes, unleashed dogs, park rangers, nosey onlookers – you name it. After couple of ‘expeditions’ you will start to enjoy your trips to the point that getting out of the shack is actually as much fun as making contacts.

In Sydney, there are countless great spots for portable satellite activity. For example, Dobroyd park above Manly is practically noise-free, and offers great horizon to the South East.

My favourite spot is Barrenjoey Lighthouse. Yes, ham radio can be enjoyed even in a busy city environment – if you are prepared to step-out of your comfort zone.

Now to Part 3.

The problem with this part of the tutorial is that there is more than one way to skin a cat. As I am a more practical than technical person, I’ll offer here a solution that works for me. Not the most intuitive, but definitely very reliable. Once you set it up, it works forever.

The beauty of IC-9700 is that all the communication between radio and PC goes through one single cable. That cable ‘transfers’ the sound and transfers data with two ports. This is the major improvement when compared to previous generations of ICOM radios, IC-7300 for example, which offers only one virtual data communication port.

On the first installation, two virtual ports are created. In my case, COM6 and COM7.

ICOM calls them port A and port B.

While the GreenCube digipeater is on 435.310 MHz, due to the Doppler effect, it is necessary to track and correct both receiving and transmitting frequencies. This is done with the help of a program called SAT32 which ‘talks’ to the radio via a lower (CAT) port.

The higher port is used for another application, but more about that in the next instalment.

SAT32 is an ancient piece of software written by DK1TB, but it works.

http://www.dk1tb.de/indexeng.htm

Download SAT32, then install both SAT32 and the SAT32ISS add-on.

Start SAT32. The first step is to input your location and then set the communication between the SAT32 and radio.

Three main settings: your QRA locator, selection of lower COM port (in my case COM6).

Get rid of all satellites except for IO-117. Finally, update the Kepler data.

Exit the SAT32 – you wont need it ever again.

Start the SAT32ISS. This is the only window to be open. If you get the previous setting right, a little cursor will point at your location. Start the CAT by hitting -C .

A second later, the display on IC-9700 will show the current Doppler frequency and from then, the radio frequency will be controlled by SAT32ISS.

Of course, there is a fairly straight forward tutorial on DK1TB site about particular settings, specifically written for IC-9700 users.

If you succeeded then congratulate yourself – well done. The rest of the setup is less complex.

As already mentioned, there are numerous other options when it comes to Doppler tracking and CAT control. Your logging software may have a similar application built in, or maybe your antenna rotator has it. Check YouTube tutorials too. The main thing is to understand the need for frequency adjustment on both RX and TX, and to automate such tasks so you can focus on pointing the antenna to the satellite and making contacts.

Inevitably, you will get stuck somewhere along the way, but rest assured that it is just a matter of time until you get it right. After all, others have done it already: Here is the list of fellow VKs I’ve worked on IO-117 with in the past week or so (plus over 100 JA and US stations, as well as Argentina, Chile, Hawaii, Guam, India!)