[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Unused resource.......AO-07

In this thread it was recently asked what the minimal set-up is to work
this bird. As a new amsat member who has been getting his feet wet with
AO-51 and SO-50, I would also be quite interested in this problem.

It seems to me that the UO-14 and AO-27 glory days produced a goodly number
of web pages / operating guides that can assist someone starting out in FM,
but that the transition from there to the CW/SSB LEO sats is not as well
covered in the Googleable Universe. (This transition is often expressed in
a sentence, like, "once your Az/El rotor with 12 element beams is installed

Based on my enjoyment of the FM sats, I bought a FT-817, in part in order
to listen to the other modes of amateur satellites. (The satellites really
put the fun back in radio listening, at least to those who share the
sentiments recently expressed by Emily on this list.) For the last week,
I've listened to several passes of several birds using two antennas: a) a
quarter-wave vertical for 70cm with counterpoises soldered to a bnc
connector; b) a home-made crossed element beam with 6-element yagi on 70cm
and 3-element yagi on 2m (otherwise known as a arrow-antenna knock-off :-).
Using both of these *indoors* connected to the radio with <10' of RG-58ish
line, I found the following observations:

1. LO-19 

This can be heard with antenna (a) on just about any pass over 10 deg!
There is fading, and I'm not sure I could copy the code reliably. Indeed,
for laughs I replaced the vertical with the rubber ducky that came with the
FT-817 and LO-19 was still audible *indoors*. 

With (b) it is quite copyable, but a handheld beam leaves one with no free
hand to write down the code.

2. FO-29 

Beacon and morse audible with (a) on many passes. Using the beam, as long
as it is pointing through an exterior wall, makes the SSB intelligible.

3. AO-7

I've had luck once with the 10m beacon, but not with the 70cm. I have fewer
opportunities to listen to this, since it is only operative in the sunshine.

I'm aware that this is by no means optimal equipment: my goal is to
establish a baseline of sorts from which to measure any improvements, and
to provide a guide for people with minimal setups. To that end, I'd be most
interested in similar observations. I plan to move on to an external
fixed-antenna setup, either with eggbeaters or QFA antennas. A low-cost
Az-only rotator might also be in the cards.

Discussion has made it clear to me that the AMSAT journal has had some
articles in recent issues that pertain to my joureny. I wonder if perhaps
the organization would consider it in its best interest to make the best of
these available to the general public in order to prime the pump.
Alternatively, a members-only back issue site would be wonderful, but I
know how much work that can be. (I have bought the journal CDs, but there
is a gap between those and the subscription that comes with my membership.)

And finally, a note on the FM sats: when AO-51 returned to V/U operation
these last two days, I was greatly impressed by its strength compared to
SO-50, which I'd been working as a fall-back. My interpretation of their
web pages is that AO-51's output is 1/2w, and SO-50 1/4w. What a critical
3dB that is! 

(The other factor that should be explained to any newcomer is that AO-51
seems to output a signal 100% of the time; whereas SO-50 outputs like a
repeater: only when there is input. As a result, AO-51 is much easier to
find with a handheld beam, and a SO-50 operator might need to 'ping' the
satellite with a call to find it.)

73, VE9QRP
Bruce Robertson, 
Dept. of Classics, Mount Allison University
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org