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Re: [CQ-Contest] path loss per hop

To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] path loss per hop
From: Steve London <n2icarrl@gmail.com>
Reply-to: n2ic@arrl.net
Date: Sat, 02 Jul 2011 12:58:27 -0600
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
I would like to see a little more data, comparing NQ4I and K3LR to other 
well-equipped stations in the SE USA, such as:

K5GO (M/2)
NR4M (M/M)
W4RM (M/2)
N4WW (M/S)
NY4A (M/M)
K4TD (S/15)
N4PN (S/15)
W4ZV (S/160)

Steve, N2IC

On 07/02/2011 09:30 AM, Rick Dougherty NQ4I wrote:
> The following consists of a short study of reverse beacon values
> generated during the ARRL CW test on 19 and 20 Feb 2011. The study
> compares NR5M and NQ4I
> for signal levels(read db or snr numbers) from 3 very active sites in
> Europe during the contest. Assumptions are 1500 watts at each station.
> And just so some one doesn't say I am using too much power I will
> restate my invitation for ANYONE to visit during a contest and bring
> your own Bird Wattmeter and measure the output on ANY of my amps! With
> that said. The next assumption pertains to antennas...NR5M's station
> and description is availabler on his web site and using some
> reasonable assumptions. For Instance on 80m NR5M is using phased 4
> squares or about 8 db gain...I use a 3 by 3 vertical array with a
> theoretical gain of 6.5 db....so using the previous mentioned path
> loss figure of 1.4 db then NR5M and NQ4I are equal? The number being
> quoted is indeed correct for ionospheric losses, but fails to consider
> path losses from ground reflection. The 40 Meter system are fairly
> close in Figure of merit and gain. NR5M has a stack of 4 over 4 OWA's
> and NQ4I has a 3 over 3 stack of Telrex 3m29's. On 20m NR5M has a 4 Hi
> stack of 6 el yagis and NQ4I has a stack of 8 over 5 over 5 that has
> approximately same Figure of Merit as NR5M. on 15m NR5M has  4 HI
> stack of 6 el yagis and NQ4I has 8 over 8 or 8 stack...advantage to
> NQ4I on 15m. 10m is not consider in the study.
> Here is how to do it...go to the reverse beacon site and do your own
> analysis...it won't change...I have made this same analysis after each
> and every contest since the reverse beacon site appeared. My contest
> team and I analyze the data to see our strength and weaknesses. And I
> especially compare my 160 results!
> When you first load up the comparison, the number of spots are very
> telling...in every case NQ4I has more spots than NR5M...can only be
> one thing! PATH LOSS!!! Or NR5M took some un-necessary time off?
> Lets look at the three sites and see what they show in the related
> signal strengths between NQ4I and NR5M.
> DK9IP 29,011 spots NQ4I spotted 220 times and NR5M spotted 105 times!
> Only difference here is Ground related path loss. NR5M's first hops
> are most likely over land masses with mountainous terrain which
> contributes greatly to spraying or splaying of the signal=greater
> loss...had NR5M's hit water on the hops there would have been less
> loss.
> On 80m somewhat equal on this day but NR5M is not able to maintain a
> signal level for nearly as long and as strong as NQ4I.
> On 40m a very obvious 6-10 db and sometimes more discrepancy between
> the two stations. And is you look closely at the early evening you can
> see the opening time for both stations. Advantage NQ4I.
> On 20m Advantage NQ4I
> On 15m Advantage NQ4I
> Lets now go to S50ARX with 34,832 spots....NR5M 107 spots and NQ4I 205
> spots....advantage NQ4I.
> On 80m greater presence at the skimmer site Advantage NQ4I.
> On 40m 6-10 db across the board. Advantage NQ4I
> On 20m Greater presence and 6 db difference Advantage NQ4I
> On 15m Offsetting data. No Advantage.
> Next is ES5PC with 27, 849 spots. 132 spots for NQ4I, and 24 spots for
> NR5M...Advantage NQ4I.
> On 80 m No spots for NR5M. Advantage NQ4I
> On 40m Huge presence difference NQ4I Advantage
> On 20m Huge presence NQ4I. Advantage NQ4I
> On 15m only one spot NR5M. Not enough for comparison. No Advantage.
> Now using the same analysis lets compare NQ4I with K3LR (not an east
> coast station by one admission) But I intend to provide data that K3LR
> is an EAST coast station.
> Same date, same 3 sites but throw W3LPL in the mix too.
> DK9IP 29,011 spots . K3LR 252 spots W3LPL 232 and NQ4I 220. Advantage K3LR
> On 80, 40,and 20m there is 6-10 difference in favor of K3LR and W3LPL.
> Could that be the elusive PATH LOSS???  I won't bore you with the
> numbers you can go and look them up yourself. They don't lie. They
> don't belittle. They don't intimidate. They simply STATE the facts.
> Close study of the data in this comapsison shows that K3LR's signals
> track W3LPL to the db...I mean it could not be closer in comparison.
> Look for your self. K3LR is close enough to New England to benefit
> from the Advantage.
> Go to the other two reverse beacons and you will see the same
> thing...Is a station in W4 or W5 is competitive in this contest? Can
> they be? Spend enough money? Work enough hours? Engineer to the max?
> None of those will compensate for parh loss and distance involved.
> So before you belive some of the numbers being spouted out here. I ask
> you to consider who is telling "the rest of the story" and who is
> muddling the waters.
> I really appreciate the votes of confidence I have received in the
> past few days...I took a few days off to let things settle down a
> little...and to try to remove myself from the
> attacks. In the words of the Terminator ...." I will be back"
> NQ4I
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