Tuesday, August 24, 2010
QRP via Amateur Satellite AO-51!
Yesterday I was able to make three "QRP" contacts through the satellite AO-51, woohoo!
I used my Yaesu FT-817ND coupled to an Elk 2m/440 log periodic antenna sitting on a tripod. The radio has 5 watts maximum output, so this was definitely "QRP"! So that I could quickly correct for the doppler shift, I programmed five memories into the FT-817ND, covering the base frequencies (435.300 downlink, 145.920 uplink) plus or minus 10 kHz on the uplink and 5kHz on the downlink:
1. 435.310 rx, 145.9150 tx pl 67.0
2. 435.305 rx, 145.9175 tx pl 67.0
3. 435.300 rx, 145.9200 tx pl 67.0
4. 435.295 rx, 145.9225 tx pl 67.0
5. 435.290 rx, 145.9250 tx pl 67.0
I tried three passes total. On the first pass (6 degrees maximum elevation above the horizon, to the east) at around 3:30pm I heard nothing -- not too surprising given that I have a large hill to the east. On the second pass (57 degress max el, east) at 5:00pm, I heard quite a few stations on the satellite (yay!) but the downlink was so crowded I didn't have any luck with calling. Finally, at 6:48pm there was another pass (16 degrees max el, westerly pass). I was hoping that the position of AO51 out over the ocean would reduce the number of users quite a bit. Also, to improve my chances, I set up in an area with a clear view to the west -- operating "portable" in the back of the truck. As soon as AO51 came across the horizon I could hear it well, and right away was able to make three contacts -- KA6SIP in CM97, NN6T in DM25, W7IN in DN27 -- yay!! I heard KL7XJ in BP40 as the satellite continued towards Alaska, but wasn't able to make contact. Signals on the downlink didn't get much above S1 or S2 at peak, but it was easily possible to communicate over the satellite with S0 signals.
Overall, this first set of sat contacts was a lot of fun! I had worked satellites back in Oklahoma in the mid-90's, and it's nice to get back into this mode.