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Portable AO51 operations as LA/PA3GUO/P

Dear all,

This summerholiday we went to Sweden and Norway. In a three week period
we stayed on abouth 8..9 different campgrounds. So whatever amateurradio
stuff I would take with me would need to be small and quickly to assemble
and disassemble.

This year I wanted to do:
- APRS via ISS (as I know how to use the ISS station and its very reliable)
- AO51 FM voice mode V/U

In a small case I packed the following equipment:
- FT817ND: all mode HF-440MHz trx (battery powered)
- TH-D7: FM 145/440MHz trx with built-in TNC (ISS APRS, AO51 435MHz)
- SEC1223: power supply to charge the transceiver batteries now and then

For 145 & 435 MHz I used two yagis based on the DL6WU design. These
beams I call my 'wash-pin antennas'. The wash pins are used to hold the
elements on the boom. Slices of the innertube of a bike (black rubber) are
wrapped around the boom. The washpins are inserted inbetween the boom
and these rubber slices. And the elements can be clamped into the
washpins within seconds. In fact, assembling the whole antenna takes less
then a minute. For satellite operations I use a cheap clamp to hold the two
antennas together (for detailed pictures:http://www.qsl.net/pa3guo).

Well, it was really great and a lot fun ! During the very first AO51 contact I
was so excited that I mixed up callsigns (used LA/PA3GUO/P, where it
should have been SM/PA3GUO/P, as we did not reach Norway yet). In the
next 15 days I worked AO51 almost every day using my portable station,
it was very nice to hear the so many ham-friends via the sat in the remote
areas we visited.

Results / Lessons learned as LA/PA3GUO/P:

I assumed I could used ISS for APRS (for the family to be able to track us),
but I did not realize that Norway is too much North for ISS, maximum elevation
around Oslo is already no more than 15 degrees, with soo many high mountains
around me ! Poor preparation from my side, I entirely overlooked this - HI.

AO51 Passes:
What is a disadvantage to ISS, is an advantage for AO51: due to the fact that
we were so much North, there were much more (low elevation) passes
compared to the normal North/South and South/North passes. Lots of fun and
extra time available to operate the satellite.

AO51 Busy?
Where normally in Central Europe there is very busy traffic during the entire
pass, I experienced in Norway very often that I had the 2nd part of the pass
the satellite for myself: when AO51 got North of Oslo I often heared either no
stations or stations you normally do not hear (OH for example).

AO51 (Mode V/U) downlink power:
There seem to be discussions around the downlink power today, but honestly,
with the THD7 and the 7 elements beam I had always noise free audio, also
at only 5 degrees elevation. No pre-amplifiers. To me the downlink power is
more than enough.

AO51 (Mode V/U) uplink power:
Wow - I knew it, but 5W into a 4 elements hand held beam is more than
enough to get noise-free over the satellite. I used the FT817, in one case
even without the beam but simply with the rubber flex antenna mounted
directly on the FT817.

One hand for the antenna, one for the microphone ... and as a result I could
not take notes and write down the contacts I made. Listening back to one of
the recordings I found out later that I called the same station twice in one
minute (sorry EJ4ABB)... Next time a headset would help out great. People
walking by however, seeing me pointing and waiving with my glittering
aluminium sticks at the sky, would most likely argue I already qualified for
the 'Idiot of the Campground Competition' anyway ...

Conclusions after operating AO51 at 8 different campgrounds within 3 weeks:
1. Big thank you to the Command Team for having AO51 in V/U during my holidays (what a lucky guy I 
2. Next time I will use even smaller antennas, less elements will do as well.
3. AO51 is a great satellite for portable satellite operations in remote areas.
4. Further deployment of APRS/Digipeating options on AO51 would be great as ISS does not reach all 
5. A THD7 can convert lat./long. position (degrees) into locator/square code: very handy
6. Operating satellites is a great holiday activity - thanks to all keeping AO51 operational !

Audio recordings:
With my cellphone I made the following recording of an AO51 V/U mode evening
pass, operated as LA/PA3GUO/P:

Henk, PA3GUO
email: pa3guo@amsat.org
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