A chance to work an astronaut on UHF

[VO1ONE]

This weekend (Jan 14-15 UTC) Bill McArthur plans to operate on the UHF band exclusively.

It is his desire to work all continents on the UHF band from
the International Space Station.

The frequency he will be using will be 437.55 simplex. Due to the high Doppler effect on this band, one will need to operate split frequencies for most of the pass. A very simplified chart showing memory assignment for transmit and receive with 5 KHz spacing is below as an example .

Mem. TX - RX
Ch A - 437.540 - 437.560 Acquisition of signal (AOS)
Ch B - 437.545 - 437.555
Ch C - 437.550 - 437.550 Time of closest approach (TCA)
Ch D - 437.555 - 437.545
Ch E -437.560 - 437.540 Loss of signal (LOS)

Good Luck and 73,

Kenneth G. Ransom - N5VHO
ISS Ham Radio Project Engineer
Johnson Space Center
Houston, TX

http://spaceflight.nasa.gov/station/reference/radio/
http://www.issfanclub.com/
http://oscar.dcarr.org/index.php
http://www.ariss.net/
http://www.amsat.org/amsat/archive/sarex/48hour/threads.html

 

[VO1ONE]

Proud to say I was able to work Bill McArthur on the space station today via the UHF simplex frequency! 59 nice strong signal. I made it with only 5 watts, too! Bill was very active today on many of the passes. The number of passes he was on far outweighed the amount of passes the packet was on. He had made contact with every continent early in the day. Hopefully tomorrow will be like this as well!

A quick note to mention, he doesn't seem to be signing at the end of a QSO or call QRZ so you are going to have to just use your best judgement and throw your call out there! I'm preparing my SASE as I write this. Looking forward to having a QSL card for this contact. Best of luck to everyone tomorrow! By the way, if you are in Alaska, this is the only state Bill hasn't worked yet and he would very much like to so he can have WAS. If you are in a place like Hawaii, you will likely have the entire pass to yourself! The further inland you are and the closer you are to highly ham populated areas, the harder it will be for you due to all the stations calling. A combination of skill in pointing the antenna and compensating for doppler as well as ERP will determine whether you get the contact or not.

73,
Mark VO1ONE

 

[KE4EST]

Glad to hear that you worked him Mark. I missed it.