[HSMS] W8WN answers questions on Other Showers



To: hsms@tree.net
From:  Shelby Ennis, W8WN 
Subject: [HSMS] Other showers, etc

I've had several ask questions about HSCW and others showers, station
improvements, etc.  I'll try to write something on this, but don't have
time just now.

Most of your questions on the showers themselves can be found in several
articles.  Two that are absolutely necessary reading for MS operation are
the second article by Walt Bain, W4LTU, published in QST May, 1974; and one
by Mike Owen, W9IP, published in QST June 1986.  If you don't have the old
QSTs, both (and lots of others concerning all facets of VHF operation) have
been reprinted in the ARRL book "Beyond Line of Sight", edited by Emil
Pocock, W3EP.

Regarding specific questions about the various showers, nothing has ever
been written on this (concerning HSCW), so far as I know.  There's a lot
out on the showers themselves (W4LTU, W9IP, etc).  These are the main
references.  But to try a quick summary - When a sharp and/or large peak is
expected, SSB is really more efficient than HSCW.  SSB's strong point is
that you can do a complete QSO (or sometimes 2 or 3 QSOs) on a single
overdense burst.  Now, over here in the US, we don't use random SSB very
efficiently.  Nearly everybody congregates on 144.200.  When a big burst
comes thru, it's nothing but QRM.  But the idea for a large, short peak
such as the Leonids is to use SSB for efficiency.  The peak of the Perseids
is the same.

HSCW is most efficient when the other modes are least efficient.  HSCW
doesn't require a shower at all!  Watching the Europeans' messages early
this year, many of them were making 10-20 random HSCW QSOs per day during
non-shower times!  But the Geminids and Quadranatids, while both are large
showers, usually do not have such a sharp peak as the Leonids.  They may be
pretty good for a day, two days, or more (and maybe very good at the peak).
 They should produce some good overdense bursts for SSB operation.  But
they should also provide a lot of pings and short overdense bursts over a
period of several days.  Their velocity also isn't as great as the Leonids.
 This gives a slightly different quality to some of the bursts, which I
really can't describe.

Then there are a number of minor showers, with ZHRs of 20 or less.  The
main one of these is the Aquarids.  Actually, this seems to be a number of
small showers all about the same time and/or one after the other with
similar radiants.  This (these) are spread over much of the month of July
and August.  Actually, the dozen or so minor showers don't do much; but
there may be just enough enhancement to really make HSCW shine.  There's
also a major daylight shower in June that is little used.  The particles
are very small, so it isn't as good as some of the others.  But this again
might be an ideal shower for HSCW.  

The fact is that, except for a few transplanted Europeans, everybody over
here on this side of the Atlantic is brand new to HSCW.  We just don't know
enough about what to expect thru the year.  And there really aren't enough
of us on yet to make CQs really effective.  So we need to keep working and
to keep pushing to interest others in the mode.

Probably the biggest improvement for MS that can be made is to get the
antenna higher.  Of course, that's also the most difficult!  Since I live
in a small valley, I have trouble working out by low-angle types of
propagation.  Obviously, a good antenna helps.  (Try not to get too sharp!)
 And more power helps more on HSCW than it does on other modes, it seems,
because HSCW relies on underdense pings, not overdense bursts.  W4LTU
wrote, "For a normal distribution of meteor sizes, you may expect the
number of bursts received to increase as the square root of the power
increase; that is, the number will double if the power is increased by
four.  This is true for underdense bursts at both vhf and uhf.  For
overdense bursts, the variation is far less, and little improvement in
number is likely with reasonable power increases."   (QST, May 1974).  

This is just a short summary, as I just don't have time for anything else
right now.  But all I can do is repeat and summarize the above-mentioned
articles.  There are some other excellent ones, but these two are probably
the best.  If you study them, play with OH5IY's MSSOFT prediction program,
they get on and operate, you've done about as much as you can to prepare to
make some QSOs.

73,
Shelby, W8WN - EM77bq
w8wn@ne.infi.net








 Return 



Comments:  Rein, W6/PA0ZN 



 Top Page