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Topband: Re: [160m] Spot Light Effects...

To: "Tom Rauch" <w8ji@contesting.com>, <Topband@contesting.com>,<160m@mailman.qth.net>
Subject: Topband: Re: [160m] Spot Light Effects...
From: "Ford Peterson" <ford@cmgate.com>
Date: Mon, 3 Jan 2005 11:19:29 -0600
List-post: <mailto:topband@contesting.com>
Tom wrote:

> I agree with you Ford. It would be very interesting to log
> signal level changes over certain paths, even if local.
> That would be information that has value to the entire
> community, even if we don't know or can't prove why it
> happens.

Then let's do it!  If a few talented folks step forward and contribute some 
computer prowess, we could make this an interesting and scientifically 
significant breakthrough in understanding the physics of this wild and whacky 
world of Topband...

> It seems to me the duct theory falls totally apart when
> applied to a signal from NY to my QTH in GA. The extremely
> low power beacon signal on 80 had exactly the
> characteristics DX signals from 10,000 miles often do.

Likewise, some of the locals here in MN are becoming active on Topband and are 
VERY active VHF/UHF contesters.  I have heard them make comments about their 
bewilderment as to the connection of E propagation on VHF to topband spotlight 
propagation.  Again, they have no proof--neither do I.  Only gut speculations 
after sitting and twiddling the knobs for dozens of hours on end on busy 
Topband weekends.
 
> We don't need to have accurate absolute levels, but we need
> to have accurate level change data. The major problem is
> accurately recording relative level changes over a long
> period of time.

I agree completely.  I have software that reads the dials on my IC746 and 
reproduces the S Meter on the screen in quite excellent fashion.  So the data 
can be extracted from the AGC loop in these radios.  Don't ask me how.  My 
manuals look like gobbly-gook but do describe how to do the software query.  
I'm thinking of a QSY to a beacon, query the meter 10 times in 5 seconds, 
average the results, and post it to a file.  Then QSY to the next beacon, and 
continue the process for the entire evening.  12 beacons, 10 (or more) queries 
per 5 seconds, gives 120 data points per minute.  Times 100 stations, is 12000 
data points, times 60 minutes, times 12 hours, is only 8M points summarized 
down to 864K points.  Record grid square (integer), frequency and result 
(integer) could be as few as 4 bytes of data -- a data file of 3.5MB per night. 
 That's nothing in terms of cumulative data complexity.  The complexity comes 
in the proper coordination of it all--and getting people to participate in the 
project.

> There also might be use for modest to high power beacons
> tucked out of the way of high traffic volume areas on 160.
> Perhaps that would eliminate the need for so many CQ's that
> largely go unanswered. Either that or we should consider
> calling frequencies. The spotty nature of propagation on 160
> often means stations in one area that on any particular day
> are unreadable waste a good bit of time and energy trying to
> stir up activity. A series of modest power beacons with
> reasonable antennas scattered around the world, especially
> in combination with a calling frequency, would (at least in
> my mind) be a real asset.

I guess in my mind's eye, I've been pondering a series of simple experiments 
involving a few evenings of various propagation conditions.  It sounds like you 
are pondering a more-or-less permanent system.  Finding dedicated people, with 
the right compliment of equipment, in the right locations, all-the-time, would 
be virtually impossible and quite problematic for the community to digest.  
Nobody wants to 'give up' a single kHz of topband to beacons or any other 
'noise source.'  But most could part with the bandwidth for a couple of 
evenings for a good cause.  I'm thinking that a series of initial experiments 
involving a few weekday evenings may prove quite interesting.  At least that's 
my view.

If there are parties interested in figuring out the technical aspects of such a 
project, contact me off-reflector.  Maybe I'll put together a team that can 
investigate and then report progress on these reflectors.  I would likely 
choose to start a reflector with only the "team" as members, to facilitate 
communications and limit 'opinions' on these matters to a minimum.  Human 
horsepower needed involves knowledge of topband, radios, software, and 
raw-brute-strength.  This could be very interesting indeed...

73

Ford-N0FP
ford@cmgate.com


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