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UA9FBV > SAT 12.06.05 03:59l 70 Lines 3621 Bytes #999 (0) @ AMSAT
BID : ANS-163.03
Read: GUEST
Subj: AO-51 Configuration for Field Day
Path: DB0FHN<DB0MRW<DB0SIF<DB0EA<DB0RES<ER3KAZ<UA9FBV
Sent: 050612/0255Z @:UA9FBV.PRM.RUS.AS #:27950 [Perm] GATEWAY $:ANS-163.03
From: UA9FBV@UA9FBV.PRM.RUS.AS
To : SAT@AMSAT
AMSAT News Service Bulletin 163.03
From AMSAT HQ SILVER SPRING, MD.
June 12, 2005
To All RADIO AMATEURS
BID: $ANS-163.03
AO-51 Field Day Announcement from the Echo Operations Group
-----------------------------------------------------------
For the ARRL Field Day Event this year AO-51 will be configured in Mode V/S
FM Repeater. The uplink will be 145.920 mHz. The 67 Hz tone will NOT be
used. The downlink will be 2401.200 mHz. There will be a long duration
operating session leading up to Field Day when AO-51 will be configured in
Mode V/S to give users the opportunity to test their Field Day stations. In
June, AO-51 will be in Mode V/S the weekend and entire week before Field
Day. Take advantage of these operating sessions to setup and test your
Field Day station before the actual day arrives.
Working the Mode S downlink on AO-51 does not require a large investment in
equipment for your Field Day station. A satellite dish is not required to
operate this mode. Gould, WA4SXM, copied the S downlink using just his G3RUH
patch feed during the early days of testing the S band transmitter on Echo.
Drew, KO4MA, has operated portable with a Transystems downconverter using
the dipole feed and a corner reflector on numerous occasions. Mike, KE4AZN,
has operated portable with either a 3.5 turn helix feed (feed only, no dish)
or a homebrew K5OE patch antenna, held out the window of the car. Mike has
also operated mobile on Mode V/S by attaching the helix feed and
downconverter to the trunk of the car. Clare, VE3NPC, has reported excellent
receive signals using a 3.5 turn helix and a K5GNA downconverter. Any of
these Amsat members can be contacted at their "@amsat.org" email address and
would be happy to help Field Day users get setup for Mode V/S. If your IF is
on VHF (which most are), an HT or other mobile FM rig will work fine as your
downlink receiver. The large 5 kHz steps of these radios actually make
tuning the fast moving Doppler on S band much easier.
Use the scheduled Mode V/S sessions to practice before heading out for Field
Day. If you have not worked the S band downlink on AO-51 previously, a few
passes monitoring the downlink and practicing the Doppler correction will be
very helpful. The Doppler shift on an AO-51 pass is approximately +/- 50
kHz. There will be lots of activity on Field Day, therefore getting your
Receive capability working well before transmitting to the satellite, will
keep your station from causing unnecessary QRM.
The uplink for AO-51 does not require a large Yagi antenna to be successful.
Any good mobile omni direction whip antenna or other omni directional
antenna will work fine, especially if all stations work together during the
passes and not try to dominate the satellite. Therefore, it should not be
difficult to setup an antenna that will work for the uplink to AO-51. If you
have a Field Day station with Mode V/U capability, you already have the
uplink covered.
A webpage will be setup with a few pictures and text on various AO-51 Mode
V/S station options. This will not include every option available, but will
hopefully assist a new Mode V/S user with some ideas to get started setting
up their station, and show that is it not difficult to get setup and working
the S downlink on AO-51.
Web URL: http://www.graceba.net/~mkmk518/echofieldday.html
With the V/S configuration of AO-51 and the other satellites available, we
will have a nice compliment of modes to operate during Field Day.
73 KE4AZN for the Echo Operations Group
[ANS thanks Mike, KE4AZN for the above information]
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