Satgen 17 by GM4IHJ   26th July 89

Voyager II at Neptune      NASA's Voyager II space probe will pass
within 5000 km of the planet Neptune on August 24th this year.Voyager
has already sent back excellent picutres as it closes with Neptune,
and these have revealed bands of clouds parallel to the equator , very 
like those on Jupiter and Saturn, but not as colourful. In addition to
these similarities with the two big gas giants, Neptune has also shown a
large white spot, but unlike Jupiter/Saturn  the polar area of Neptune
has a rather dark black appearance.
After leaving Neptune , Voyager will not see any more of the known planets
of our Solar system, because at the moment tiny Pluto is actually closer
to the Sun than Neptune is. Voyager II will hopefully stay in contact with
earth for perhaps another 15 or 20 years , if we are lucky. But thereafter
it will continue on in silence for at least another 25,000 year before it
approaches another star system.
The smallest aerials being used by NASA to listen to Voyager are 32 ft
dishes, and these are essential if the wideband data from the space probe
is to be received without corruption. Indeed several of the dishes
tracking Voyager will be 100 ft or more in diameter.BUT if you are content
just to search for a very faint signal ( with no hope of demodulating it),
you might get something on a smaller dish. Voyager II sends on 2295.24
2296.481, 8412.284 , 8415.0 and 8420.43 MHz. Neptune is presently about 2
degrees east of Saturn , transiting your meridian at about 2120 ut.

UFO's     The mystery 435.974 sats with the 101 minute orbital period 
have not been heard for over a month, but the other UFO thought to be
the US Polar Bear experimental sat (period 105 mins, inc 89 degs), is 
still there providing useful morning and evening orbits for Polar 
Ionosphere checks,
.
PACKSAT preparations at IHJ have concerned software preparation, which
goes well, and testing of omni directional 70 cm reception aerials, which 
goes not at all well. Attempts to receive JAS1 Fuji Oscar 12 on  Digital
mode on an omni directional aerial gave very poor results at 2042 on 22nd
July.So it could well be that Packsat will need a more complex aerial .
Please note that if you are thinking of preparing for Packsat, 435/28 MHz
receive pre amps and converters may not be optimum for 437 MHz Packsat
reception. So be careful about any converter you buy.Some only cover
432/433, some cover 432 to 435 inclusive using switched crystal, but what 
ever you get remember it must cover 437MHz.Equally important do not go for
a 432/144 MHz converter because that will put your receive IF directly on
your transmit frequency.

MIR    is now coming over UK in the evenings before sunset. It has been 
heard on 166.122 MHz , but only very infrequently. Observation on its 
recent night passes over UK, did not indicate any Attitude Control or
Communications problems. There has been no repeat of the " surging " radio
signals heard in May/June.   73 de GM4IHJ  26th July 1989