Date: Thu, 22 Feb 2007 14:46:19 +0000
From: "Louis Anciaux" <hp3xug@gmail.com>
Subject: Re: Topband: This morning on 160 meters
For W2PM,
Interesting word you used: "Assess" in making an indication of the
number JAs on TB.
You are correct, not only for JA, but for a lot of the "rest" of us
trying to do something on TB, that physical limitations play a BIG
part in any one's capabilities.
However, if you consider the physical constraints of one's station -
starting with the likes of whom we all know on the band using LARGE
stations and huge real estate antenna farms - as the size diminishes,
so too does the signal capabilities (both TX & RX). Not perhaps a
sound mathematically-correct analysis, but serves to demonstrate the issue:
As one reduces the Antenna Capture Area capabilities, say by an order
of magnitude for each step, it follows the signal levels ought also
reduce a similar order of magnitude
If one reduces such large systems say to a small lot (not uncommon in
JA, as you indicate) by 4 orders of magnitude; then, you are also
seeing a similar reduction in signal levels, not withstanding we
haven't added in the order of magnitude of power levels that are most
common as well. This equates to a 40 dB reduction in signals (-50 dB
if you make allowance for most common power differences).
There is also the aspect of the number of JAs on band at a time,
compared just to US hams, which is likely at least an order of
magnitude as well. Would surmise you are running a KW.
Now, therefore, it follows from your station capabilities and you
enjoy a JA QSO on TB at an 559 level, it is most likely one of the
"Big Guns" as they like to be referred of. Drop this signal level
down just 10 dB, that results in an S3 level signal (am sure it will
rarely be 539 then). Another 10 dB down and may be in realm of many
able to copy weakly your sigs, and they are probably in the 100W
category. You didn't even copy the 20 signals who were calling you!
But, that's OK? The band is dead at your end.
I can tell you from experience - 2 years /DU1 and 2 years as HL9UH -
the number of JAs on any particular band, DX freq, etc is something
you cannot even imagine, until you are close enough to hear
them! And, that was 15+ years ago! The one thing you cannot say, is
that there are few JAs on the band! That you can say is, that you
heard few JAs on the band.
Maybe you should work on the RX capabilities of your station - you
might be quite surprised, and pleasantly so, at what you will hear.
Warm 73 and good DXing,
Louis
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