Sky Talker

Ready for actionOn the F-Troop net this morning, VK6AS mentioned there was another good pass of SO-50 today. With last weekend’s mistakes learned from, I had another shot at it. I thought I could hear snippets of voice modulation down in the static when the satellite was still at -5º elevation which seemed odd. It wasn’t until about 40º that I got anything readable, and even then it was only for half a second at a time.

SO-50 passThe pass was almost directly overhead for me, so at the apex I was able to just point the Arrow straight up, and copied VK6AS’s call. I put out a call to him and was thrilled to hear his reply of congratulations. So thrilled in fact that I wobbled the antenna and lost him. I was so frantic from then on trying to find the satellite again that I completely forgot to keep adjusting my downlink and didn’t copy anything for the rest of the pass.

KG-UV920PMy Wouxun KG-UV920P arrived yesterday, so I’m finally on 70cm at home. I only have a 2m coax dipole antenna (a WARG made pogo-stick I purchased at HARGFEST ) up at the house, but I’ve heard they tune up on 70cm, but the radiation pattern is no good – being mostly straight up. That sounded perfect for a very high satellite pass, so I left the squelch open on 436.800 MHz with a recorder running – the idea being that I might be able to hear part of the pass on a recording.

When I eventually converted the audio from the Sony proprietary audio format (after having to download special Sony software and Sony drivers – way to go Sony – never forget Betamax!) I was excited to hear my calls out of the noise. I can also hear some of the voice modulation I heard out in the paddock during the pass, and I kinda think maybe perhaps I can hear some of the other satellite traffic. See what you think.

At first I thought that my good signal on the recording proved I was getting into the satellite better than the others, but on reflection I’m wondering if I’m not so sure. It’s not exactly a third harmonic of my uplink frequency, but I still suspect it might have been a local signal. Like a lot of the Chinese SDR’s, the UV920P is a fairly wide range receiver so the front end is not going to be stella. On the other hand, I don’t think I was picking up anything in the very wide range scanner I was using for the downlink, and it was on the same beam as I was transmitting on.

As for the voice modulation I heard in the field and on the recording, there are transmitters in town for a Christian FM station and ABC TV. The TV is digital, so I think I was probably hearing the Word. I might try further out in the bush for the next pass to eliminate that problem and the possible local bleed onto the 70cm recording.

Today went a lot smoother, I parked the ute at right angles to the pass so I could dump my stuff on the back, this was especially useful to leave the downlink scanner where I could read it and change the frequency. Handling the antenna is still the worst problem. I’ve obtained a good tripod, and I’ve been looking at one of the K7AGE videos – it turns out the Arrow has a threaded mounting hole under the handle and he just has a hole in the counter weight that he lines up and joins with the tripod.

I’m regretting not purchasing the duplexer. The theoretical advantage of being able to hear yourself on the downlink is not eventuating for me, so I’d be better of with just the HT. I think I’ll look into this.

I got an email from VK6MT to say he had copied me in Katanning soon after I got home, so it was nice to get that confirmation, and I’ve since emailed VK6AS to thank him for the contact and he says he’s already logged it on QRZ! So it’s official, I’m a sky-talker.

Arrow Antenna in bag

Update: (7/6/15)

Andrew forwarded an email from Allen VK6XL. Allen was tracking SO-50 during the pass and forwarded this log:

30°elev VK6MP    Cq call - no response
35°elev VK6AS    Cq call - no response
55°elev VK6MIB   Cq call - no response
56°elev VK6MP    Cq call - no response
57°elev VK6AS    Cq call - no response
61°elev VK6MIB   Cq call - VK6AS responds 
                 "5/9 good work (Adrian?)"
71°elev VK6MP    Cq call - no response

Zenith passed by SO50 and no more downlinks heard as 
elevation declines.



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