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Easy sats
- Subject: [amsat-bb] Easy sats
- From: DGuimont@xxxxxxx
- Date: Tue, 8 Sep 1998 02:34:07 EDT
An unusual interest in amateur satellites in the San Diego area prompted the
following document. It was created, no doubt by the excellent effort of the
Naugle's at the AMSAT booth at the Southwestern ARRL Convention, and the
presentations by Keith, kb1sf....
GET ON THE AMATEUR SATELLITES TODAY!
Most amateurs have the equipment to get on the Russian satellite
RS15 immediately.
What you need:
1. A receiver capable of receiving in the 29 MHz range on cw.
2. A transmitter capable of transmitting in the 145 MHz range.
either on FM, SSB/cw or both.
3. A method of determining when the satellite is going to be
in range of your station.
Use what you have for a receive antenna. Most anything will work
from a random wire to a beam. If you have a beam, turn it in the
direction of the satellite. It will definitely improve reception
when the satellite is below 30 degrees elevation.
If you have an all mode transmitter in the two meter band, you can
work both cw and ssb. If you have an FM only transmitter, make
some arrangement to key the transmitter in cw. DO NOT TRANSMIT TO
THE SATELLITE ON FM VOICE!!! You will incur the wrath of every
operator in the footprint! Ssb xmit is ok.
Again, use whatever antenna you have available. A beam pointed
in the general direction of the satellite will require less power
to access than an omnidirectional antenna. Use only the power
needed to access the bird. Remember, you are listening to your own
downlink. If the beacon is on (it is frequently off), do not let
your signal exceed that of the beacon. 25 watts EIRP should be
more than adequate on cw. TRY WHATEVER YOU HAVE! QSB is a
possiblity, keep trying.
RS15 frequencies:
start end
Downlink: 29.354 29.364 29.374 29.381 29.376 29.384 29.394
Uplink: 145.858 145.868 145.878 145.880 145.880 145.888 145.898
start end
Beacons: 29.352 & 29.399 (intermittent)
Note that the start and end uplink frequencies of 145.880 result in a
start downlink frequency of 29.381 and an end downlink frequency of
29.376. This is a result of doppler shift, and applies to all amateur
satellite operations. The frequencies in the table are approximate.
Maintain a frequency in the uplink range, transmit a series of dits,
and tune your receiver until you hear your signal. Make a note of
this pairing as it applies to your equipment, and it will be simple
to "find" your signal on subsequent passes. If you are keying an
FM transmitter, it is simpler for you to call CQ and let the other
station zero beat your signal. Your ability to "zero beat" another
signal will depend on the frequency setting capability of your
transceiver.
Many computer programs are available to determine when the satellite
will be in range. www.amsat.org has descriptions of some that are
available, and some of them are free. Or use the rs15.zip file at the
site listed below. It decompresses to rs15.txt, is in ASCII, and
is readable on most any computer. It will appear monthly, for a
month at a time, and be uploaded at the end of the preceeding month.
The beam heading will only be accurate for Southern California, but
it is possible for other users to estimate a heading using the
geographical location of the sub-satellite point. Feel free to
disseminate this information in any way you think is appropriate.
The files are available: http://users.aol.com/dguimont
sat.txt-------the file you are reading
rs15.zip------decompresses to rs15.txt
Experienced users are requested to critique this information, and
provide range information for your part of the world.
Beginners fire away with your questions.
Questions to wb6llo@amsat.org 73 Dave Disagree; I learn.
c:\rs15\sat.txt
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