HF Radio Test and Other stuff
James Coxon
Just to update everyone on the progress (yes the project is still
moving forward!). Today Steve (Rocketboy/G8KHW) tested his HF Tx that
he has been working on for the past couple of weeks. Its a modified
Rockmite 40m CW Transmitter that with the addition of a PIC now can
transmit CW, RTTY and also MFSK on 7.0140MHz with a power of just
under 500mW. Today he lifted the transmitter to 60m on a tethered
balloon and had it transmit on a 4 minute cycle rotating through the
various protocols. The transmitter could be heard on the ground with a
small wire however couldn't be heard in London on a long wire antenna.
However a quick visit to #hamradio and DJ1YFK (who originally
developed the SSTV code for Pegasus 6) listened in from Munich with
his 3 ele yagi (S5) and also a vertical (S3), he was able to decode
the transmission. So with 500mW at an altitude of 60m clear signals
were decoded 950km away. Unfortunately we weren't able to pick it up
with Alexei's station (natrium42) in Canada but its certainly an
excellent start. More info can be found on the wiki.
Also this week with the launch of Nova 11 we were able to test out the
'UKHAS Network' which uses the DLClient and Server that Rob and I have
been developing. After a bit of debugging in the first few minutes of
the flight we were able to utilise multiple stations receiving the
data transmissions from the payload, have them pass the data to the
server which checked them and then posted them onto google maps.
Overall the system worked very well with over 1500 strings being
logged from 5 stations which allowed us to show a flight path from
2000m into ascent to 2000m on descent. While there appeared to be a
loss of radio contact just before landing the CUSF team where able to
recover the payload the next day after calculating the final path and
then searching the area. Next step is to plot the listening stations
directly onto the tracker map and test the system further with more
clients.
Work has begun on a couple of latex missions to test the ballast
tanks, at present I'm putting together the flight computer which will
control the valves - hopefully will be ready for a launch in a few
weeks - which will also test the UKHAS Network again.
Feel free to get on to #highaltitude to discuss the project plans, and
also make full use of the wiki (http://spacenear.us/wiki/doku.php)
James