Michael.Chepponis@CMU-CS-C.ARPA (Mike Chepponis) (08/02/85)
Has anybody been able to copy acceptable SSTV from the shuttle? Here in
Pittsburgh at W3VC, we've been able to hear faint signals on orbit #50, and
much stronger signals on orbit #52, but nothing at all on any other orbit.
Apparently, the SAREX experiment was not turned on as anticipated, and orbit
#50 was the first orbit it was on. Both orbits were in "Mode 1" - auto SSTV
downlink (no uplinks). The pictures we did get on orbit #52 were in the
following sequence: four 8-sec B&W, one 12-sec color, one 36-sec color, then
the cw id "W0ORE/CHALLENGER", sent at about 15 WPM. Then the sequence
repeated. We were only able to hear it for slightly fewer than 3 sequences,
and of the pictures we could see, the best were the B&W ones. But even though
the signal peaked at s9+60 dB on the Yaesu FT-726R, the nulls were VERY deep,
and this caused severe hits to the pictures. As far as we can guess, the
pictures were of the shuttle bay doors and the IPS. We are using a GaAs FET
preamp and either an Isopole or the 20-ele twist antenna of our OSCAR 10
setup. Tony is running only 2.5 w, but that should be quite enough. Also,
on both passes, it was announced that SAREX would be on only MINUTES before the
shuttle passed within our range.
I'm curious what sorts of experiences others are having. We have noticed that
QRM on the downlink frequency is non-existent at this QTH (a far cry from the
W5LFL mission!). Here is the germaine ARRL bulletin on the subject:
QST de W1AW
Hr ARRL Bulletin NR 65 From ARRL Headquarters
Newington Ct August 1, 1985
To all radio amateurs bt
The launch of space Challenger mission 51F took place at 2100.10 UTC
on July 29.
Operation by W0ORE is now expected on the following schedule,
Date Old Orbit New Orbit Start Stop
Number Number UTC UTC
Aug 1 47 48 1955 2025
48 49 2130 2200
49 50 2300 2320
Aug 2 50 51 0025 0125
51 52 0155 0255
52 53 0325 0405
53 54 0500 0540
54 55 0635 0705
58 59 1300 1310
62 63 1850 1900
63 64 2010 2045
64 65 2140 2220
65 66 2305 2335
Keplerian elements for STS 51F are:
I.D. Element Set 7
Epoch 85/212.59409722
Drag 2.5e-04
Inclination 49.4884
R.A.A.N. 146.3659
Eccentricity .0006493
Arg. of Perigee 317.0027
Mean Anomaly 185.499
Mean Motion 15.86377915
Orbit Number 28
Semi Major Axis 6696.6766 Km
Anom Period 90.75
Apogee 319.5 Km
Perigee 312.3 Km
Beacon 145.55 MHz AR
73, -Mike, k3mc (with the CMU Amateur Radio Club, W3VC)
-------john@anasazi.UUCP (John Moore) (08/04/85)
In article <379@brl-tgr.ARPA> Michael.Chepponis@CMU-CS-C.ARPA (Mike Chepponis) writes: >Has anybody been able to copy acceptable SSTV from the shuttle? Here in >Pittsburgh at W3VC, we've been able to hear faint signals on orbit #50, and >much stronger signals on orbit #52, but nothing at all on any other orbit. In Phoenix, I have copied 5 orbits and worked him once. On all orbits he was weaker than W5LFL was, with the strongest signal an S4 (??) on AZDEN 3000. I have no SSTV equipment so have not looked at images, although they are on tape and will be decoded at a friends QTH. Antenna system is KLM 14 el vertically polarized beam with accurate AZ tracking and EL of 0 degrees. The weak signals were heard on relatively close orbits that would have been S9 on the W5LFL mission, so I wonder if his ERP is down for some reason. John NJ7E