[amsat-bb] repost from ARRL letter - DXCC on UHF!
nate at natetech.com
Fri Jun 20 13:48:28 PDT 2008
Wow. Mostly by EME...
I thought this group would find this amazing...
==> GERMAN HAM CLAIMS FIRST DXCC ON 432 MHZ
The world of Amateur Radio DXing has passed a new milestone: On Friday,
June 6, Jan Bruinier, DL9KR, of Niedernhausen, Germany, worked his 100th
country on 432 MHz (70 cm) via moonbounce (EME) and CW.
Samek Zdenek, OK1DFC, and Hofbauer Zdenek, OK3RM, were getting ready to
go on an EME DXpedition to Macedonia. Before they left, Samek asked
Bruinier to help test out the equipment; Bruinier gave him a beacon,
aiming a signal off the moon. According to VHF guru and conductor of
QST's "World Above 50 MHz" column Gene Zimmerman, W3ZZ, this is done by
transmitting a series of CW dashes and then stopping to listen for the
signal to return a little more than a second later. The moon averages
384,000 km from the Earth; radio waves travel at ~300,000 km/sec.
After one of these transmissions, Bruinier was excited to hear Samek
appear on frequency with a 549 signal. Thus, after an exchange of calls
and reports, Bruinier's 100th country on 432 MHz was in the log. Once
his QSL cards are confirmed in the near future, he will become DXCC #1
on 70 cm.
Bruinier's 70 cm EME operations began in 1977. He had followed the
exploits of the early EME pioneers in QST, operators like KH6UK, W4HHK,
W3GKP and W1FZJ who was conductor of the "World Above 50 Mc" during much
of the 1960s. Jan and his family moved to a semirural location in
Germany in 1976 where he could put up decent VHF antennas. Working
initially on his own, he built an array of 16 ten-element quagis
(antennas with single quad loop driven elements and reflectors and 8
Yagi directors) following the design described in QST by Wayne Overbeck,
K6YNB (now N6NB). After a few false starts with other tubes, he obtained
an Eimac 8938 and built a near-legal limit amplifier. The station
exciter was a set of Drake twins as an IF strip using homebrew
transverters with an increasingly sensitive group of GaAsFET
preamplifiers, always working at the state-of-the-art.
As time progressed, Bruinier built a bigger amplifier capable of running
1500 W continuously to deal with the high duty cycle found in EME
operation -- long, slow CW with two minute transmissions at a time --
and receiver systems that yielded noise temperatures of 60 kelvins that
could detect 7 dB of noise when he pointed his array into the ground. He
eventually transitioned from the quagis to an array of DL6WU design
Yagis fed with 1-5/8 inch Heliax, currently having a gain of 28.4 dBd.
For comparison, this is slightly more gain than the 28 foot Kennedy
parabolic dish has at 432 MHz.
According to Zimmerman, the range of contacts covered by the 70 cm band
is less than 1000 km; even under the most enhanced conditions, it is
less than double that. "To work the 100 entities needed for DXCC, EME
communications are essential. EME is the most demanding form of
operation there is in Amateur Radio," he said. "Every single aspect of
the station must be optimized: The equipment, the antennas, the feed
lines and most particularly, the talent of the operator. Even 1 dB may
make the difference between a contact and no contact. Bruinier's
achievement was accomplished the old fashioned way -- by dint of hard
work, excellent equipment, big antennas and many, many hours on the air
looking for new countries and not missing many, if any, DXpeditions to
the many countries where there is no 432 MHz EME activity."
Bruinier told Zimmerman that many people going to many countries on all
continents made this award possible: The Five Bells Group, the Yota Sawe
Group, Michale Kohla, DL1YMK, and Monica; Bernd Mischlewski, DF2ZC; Mark
De Munck, ON5FF (now EA8FF); Bernhard Dobler, DJ5MN; Mart Sakalov,
SM0ERR; Dimitris Vittorakis, SV1BTR; Gudmund Wannberg, SM2BYA; Frank
Hobelmann, DL8YHR; Joachim Werner, DL9MS, and Allen Katz, K2UYH, among
others, as well as groups from Russia, Spain, France and Denmark.
If you would like to read more details about Bruinier's career as an
EMEer, please look for his story in his own words in the "World Above 50
MHz" column in the September 2008 issue of QST.
nate at natetech.com
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