AMSAT-SM - Official Website of AMSAT-SM SwedenDear friends,
NLSA is pleased to announce availability of the LabJack PiggyBack, an add-on board for the JabJack U12. The PiggyBack allows the versatile, inexpensive, USB-based JabJack U12 to connect directly to Yaesu-type rotator control boxes.
Read about the PiggyBack here
http://www.nlsa.com/labjack/labjack_piggyback.html More information about the LabJack U12 is here
http://www.labjack.com/labjack_u12.html 73 Hkan
Klla: WWW
Finnish HF/VHF/UHF/SHF balloon experiment
Hi all,
this Autumn will see the flight of Ilmari 2003,
an AMSAT-OH balloon experiment carrying the
following hardware:
– – GPS receiver
– – 70 cm 100 mW APRS beacon
– – 3.5 MHz 1 W beacon
– – 23 cm FM ATV 1 W transmitter
– – two colour video cameras
– – Indoor Housekeeping Unit (CPU)
– – 2m in/70 cm out 1 W linear transponder
– – remote monitor and control radio interface
– – electronic remote mission abort system
– – landing parachute
– – 14 V, 12 Ah Lithium Thionyl Cloride battery
Most of this hardware is already flight ready
and will be undergoing thermal chamber testing
soon. The hydrogen balloons we have acquired
should allow us reach an altitude in excess of
30 km giving excellent range, depending on the
TBD launch site(s).
The linear transponder can support multiple
SSB/CW/digital ham radio QSO s and should be
easily copiable in our neighbouring countries
also. On 23 cm, the ATV transmitter will be
able to show either horizon or nadir views
under remote control. For reception one only
needs a standard analogue SAT-TV receiver +
TV and a decent 23 cm LNA. APRS packets are
planned to be copiable mobile and portable
for the search team and others interested.
Most of this hardware will be dry running
at our national microwave roundtable
Gigaleiri and also our national SRAL summer
camp.
For more reading, audio files and photos, see:
RFpayloads:
http://www.kolumbus.fi/michael.fletcher/ilmari.htm Everything else:
http://www.viestikallio.fi/ilmari/index.php 73 s Michael, OH2AUE
Klla: amsat
AO-40 is continuing to drift downward in ALON as predicted.
This is making the squint/range combination less favorable for passband use.
In addition, the solar angle is worsening and will shortly exceed 45 degs,limiting available power and warming the spacecraft considerably as the sun swings across the omni end of the spacecraft.
The AO-40 passbands will be turned off at MA=240 (23:50 UTC) on Saturday 4/19. They will remain off for about 4 weeks (or slightly less) until conditions improve.
– —W4SM for the AO-40 Command Team
Klla: amsat
Pictures taken today confirm that we have now reached ALON / ALAT = 51 / 20.
Magnetorquing has been turned off and we have begun
drifting down in ALON under the influence of the so-called mystery effect ( due to momentum wheel magnets interacting with earth s magnetic field ). Drift rate will
be approximately -18.2 degs / week at the current spin rate. This will place us on the other side of the sun in approximately 4 weeks, when we can decrease ALAT and begin chasing the sun back to 0/0.
The solar angles will begin increasing rapidly as we move backward and the passbands will be turned off within a few days until conditions improve. The beacon will remain on continuously.
– — W4SM for the AO-40 Command Team
Klla: amsat
Det har under en tid diskuterats om mjligheten att placera en transponder p mnen, jag publicerar ett inlgg frn en av dom ivrigaste fresprkarna.
73 Hkan SM7WSJ
—————–
Moon station or L1 satellite is not like EME !!
Hello,
The view of most amateurs on the path losses for a moon station or L1 orbit are not really true. For such large distances you don t need bigger stations than for EME ! An EME contact is completely different with a direct contact between the ground station and the satellite.
To give you some examples:
Path losses
EME: Direct (Earth -> moon-station) Difference
– ———————————————————-
70cm 261dB 197dB 64dB !!
3cm 289dB 225dB 64dB !!
Communication with a station on the moon can be done with common HAM equipment, like shown below:
On 70cm when both stations use 20W power and 13dB antennas:
– ———————————————————
Uplink 20W = +43dBm
Uplink ant. gain = +13db (medium yagi)
——————-
Uplink ERP = +56dBm
path losses = -197dB
———————
ERP on the moon = -141dB
Ant gain moon = +13dB (medium yagi)
———————
Moon reciever input = -128dBm
On 10GHz when both station use 10W power and 80cm dish ant. (36dB):
———————————————————–
Uplink 1W = +40dBm
Uplink 80cm dish = +36dB
———————–
Uplink ERP = +76dBm
path losses = -225dB
———————–
ERP on the moon = -149dBm
80cm dish moon = +36dB
———————–
Moon reciever input = -113dBm
These stations are not like EME station 🙂
When looking at L1 satellites with lets say 4x more distance the situation gets some more path losses but still possible for amateurs.
Path losses:
to Moon to L1 sat difference
70cm 197dB 199dB 12dB
10GHz 225dB 237dB 12dB
When both station increase their antenna gain by 6dB the same path conditions will stay. On 70cm the satellite can also use 6dB more power (80W), and the ground station can use an 16dB yagi instead of the 10dB yagi.
This is still within the common ham possibility.
On 10GHz the ground station can use a 1,5m dish instead of the 80cm, and the satellites power and antenna could be increased to overcome its 6dB. 🙂
This is all well within the normal amateur equipment, and still far below the needed EME equipment 🙂 What most
people think More away from the moon is more difficult than EME… is not always true 🙂
So, when do we start to build the first Moon station ? 🙂
73 de PE1RAH, William
Klla: PE1RAH