[TowerTalk] 5 db required to see?
Guy Olinger, K2AV
Wed, 24 May 2000 21:48:24 -0400
As I recall the tape, think Tom attributed the performance of the 6Y
vertical setup to the excellent low angle afforded over the salt water,
which was superior to a horizontal antenna at the angles mentioned, some
well off the max of normal horizontal lobes. These were delivering 5+ dB
advantage over horizontal antennas at important very low arrival angles.
He did refer in another part of the presentation to 2 dB as making a
difference. (This is refreshing compared to some posts here back a ways
which were trying to tout 0.2 and 0.3 as "significant".) And I can see 2
dB making a difference on a band with "flat noise" and a marginal path
with respect to the powers/antennas involved. If the propagation is
"in", though, I don't think it will be perceptible.
As to "another layer", hearing 50 stations at S0 that you wouldn't hear
otherwise is certainly a good thing, sure wouldn't throw it away, and
would pay some antenna bux for it. HOWEVER, *THAT* wasn't what we
called a LAYER. On 40 meters there were only three layers.
Station A) A dipole at a good tree height., say 50 feet. Work anything
loud from EU. Some answers to CQ's but do better S&P. Has a hard time
hearing a lot of what station B is working. Station C sounds watery and
like backscatter. Station A almost never hears what station C is
working. A) is working layer 1
Station B) A two element linear-loaded Cushcraft 40 meter yagi at 100
feet. Signals good in EU, could work through pileups, get answers on
CQ's, etc. But on the first night of the CQ WW, EU working each other
would not hear and/or work you. Only by stealth, superior operating,
and getting lucky on the calling frequency does B) grab a mult from C).
Station B is working Layer 2.
Station C) W4BVV's 70 foot boom monstrosity at 180'. Reports brought
back from Europe mentioned W3AU, W4BVV, plus one or two others, copyable
several hours before any other USA stations heard at all. First night of
CQWW get in there and works the little 50 watt low dipole EU stations
right along with the loud EU. Station C) hears EU stations answering
Station B)'s CQ's that station B) apparently does not hear. Station C)
is working Layer 3.
Been at all three stations in CQWW. Needless to say, I had a real thing
going for station C). The differences make the best stories when you and
a couple of other stations are heard hours before anyone else, but this
difference does not disappear when the band opens.
It's not provable exactly what made the difference, probably the SUM of
location propagation, location quietness, the height, 70' boom worth of
yagi with no loading (a full-size monster with HEAVY elements), having a
major LOBE in an important arrival angle, 7 MHz BC overload proofed RX,
a real kW. There were only a very few stations working layer 3. One
A bum operator can turn station C) into station B). A slick operator is
worth 15 dB not wasted.
One thing for sure, the difference between a quad and a yagi on a given
tower does not account for those layers. Antennas alone will not account
for it. Not talking about a 2 dB advantage. Everything taken together,
maybe 10 dB, maybe more. How much more does it take to be heard in EU
two hours before everyone else?
- - . . . . . . - - . . . . - - . . - . .
Apex, NC, USA
----- Original Message -----
From: alsopb <email@example.com>
Sent: Wednesday, May 24, 2000 12:48 PM
Subject: [TowerTalk] 5 db required to see?
> I lost the original e-mail. However, I believe it was W8JI who stated
> one needed 5db type improvements to see much of a difference.
> About 3 weeks ago I saw a presentation by the owner of Force 12.
> His conclusion is that 2db is a BIG difference. He had some decent
> theoretical arguements and emperical contest data from 6Y5A which
> supported this. I don't think it was because he wanted to sell more
> of his bigger antennas.
> It appears at 2db one uncovers a whole new layer of people to work
> (especially during contests) and many additional contacts on a given
> band can be worked as a result.
> My own meger experience is consistent with his conclusion.
> By the way if you already own a 4 element monobander, getting that
> extra 2db can be costly. If you've already got stacked arrays, it's
> very costly...
> 73 de Brian/K3KO
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