What's a dbworth?
JKAHRS at delphi.com
JKAHRS at delphi.com
Sat Aug 5 13:50:03 EDT 1995
On 4-AUG-1995 21:11:59.7 k0od said to K2UVG and the contest reflector
<snip>
> What is a single db--the basic molecule of a monster
> signal--really worth to a contester?
> Last year, I compared DX contest scores by power level: high, low and
> QRP.
> I concluded that increasing the transmitted power level a single db
>might increase a station's contest score by nearly 10%!
<snip>
> I played around researching this for an hour or two. Has anyone ever
> done a real study of this topic?
> -----------------------------
> Jeff K0OD St. Louis, MO USA
> e-mail: k0od at mo.net
> -----------------------------
Thats interesting Jeff. I give a program to clubs called "Dollars per dB"
where I use this as a Figure of Merit for station improvement. This is a
different approach and would be more meaningful if the actual stations were
factored in and only station in the same area were used to rule out prop as
a significant factor.....very interesting.
73, Hank/K2UVG ERIN = 0 K2UVG =1 we came thru it ALL OK!
Niceville, FL 50 miles east of Pensacola
Wish I had a video of the PRO67B "flying" tho...quite a sight
Internet: jkahrs at delphi.com
>From W0CP <wstinson at listenup.com> Sat Aug 5 18:54:40 1995
From: W0CP <wstinson at listenup.com> (W0CP)
Date: Sat, 5 Aug 1995 11:54:40 -0600 (MDT)
Subject: What's a dbworth?
Message-ID: <Pine.3.89.9508051157.A7410-0100000 at teal.csn.net>
On Fri, 4 Aug 1995, Jeff Singer wrote:
> I concluded that increasing the transmitted power level a single db might
> increase a station's contest score by nearly 10%!
>
> USA scores for contests over a 5 or 6 year period. In every contest I
> looked at, a single db was worth at least 6% improvement.
>
> I played around researching this for an hour or two. Has anyone ever
> done a real study of this topic?
> -----------------------------
> Jeff K0OD St. Louis, MO USA
> e-mail: k0od at mo.net
> -----------------------------
I wrote an aritcle on this subject that was published in the May, 1991
issue of the DX Magazine. The focus of the article was a comparison of
various tri-banders, primarily the TH-7 and the KT-34XA. To try to put 1dB
into perspective, I made a study of ARRL Sweepstakes all-time records, as
published in the 1989 NCJ. I compared the top all-time low power score to
the high power score in each ARRL section and assumed a 10 dB difference
in power. The top low power scores average about 40% less than the
high-power scores.
This data indicates that a dB is worth around 4%. Of course, there are
some unknown variables that weren't factored in, but through the years I
have concluded that 3%-4% is a decent ballpark range for the increase in
QSO total attributable to 1 dB in a contest. The SCORE increase would
actually be higher in some contests (CQWW for egs.), due to the effect of
multipliers, which might account for Jeff's higher estimate.
73, Walt - W0CP
<wstinson at listenup.com>
>From Bill H Parry <bill at tenet.edu> Sat Aug 5 21:09:35 1995
From: Bill H Parry <bill at tenet.edu> (Bill H Parry)
Date: Sat, 5 Aug 1995 15:09:35 -0500 (CDT)
Subject: Windows 95
Message-ID: <Pine.OSF.3.91.950805145756.17449A at Leslie-Francis.tenet.edu>
Have any of those who have had the opportunity to use the beta copy of
Windows 95 tried it's compatibility with the various contest programs? I
understand that there is no real DOS prompt in Windows 95 and that it may
not like programs like CT. It would be good to know before installing
Windows 95 on your computer!
Bill, W5VX
>From n3rr at cais.cais.com (Bill Hider) Sat Aug 5 22:27:33 1995
From: n3rr at cais.cais.com (Bill Hider) (Bill Hider)
Date: Sat, 5 Aug 1995 17:27:33 -0400
Subject: What's a dbworth?
Message-ID: <199508052127.RAA19828 at cais.cais.com>
All contesters should be aware of the answer to this question which is
discussed in W6QHS's book on page 10-9, Physical Design of Yagi Antennas, by
David B. Leeson, W6QHS, Pub by ARRL.
Suffice to say that the folowing message describes, emperically, what Leeson
derives theoretically. Read the book!
Bill, N3RR
At 08:06 PM 8/4/95 -0500, Jeff Singer wrote:
> Articles often say that a mere db or two is not worth worrying
>about. That sentiment even appears occasionally in postings on this
>reflector. What is a single db--the basic molecule of a monster
>signal--really worth to a contester?
>
> Last year, I compared DX contest scores by power level: high, low and
>QRP.
>I concluded that increasing the transmitted power level a single db might
>increase a station's contest score by nearly 10%!
>
> My study took into account that 1500 watt stations usually have
>somewhat better antennas than 100 watters, which in turn probably have
>more aluminum than QRP stations. I compared the highest QRP score with
>the 3rd highest lowpower score and the 5th highest QRO score. I examined
>USA scores for contests over a 5 or 6 year period. In every contest I
>looked at, a single db was worth at least 6% improvement.
>
> Note that I am talking about a db increase in transmitted power. A db
>of antenna gain on transmit and receive should add more than 10%.
>
> I played around researching this for an hour or two. Has anyone ever
>done a real study of this topic?
> -----------------------------
> Jeff K0OD St. Louis, MO USA
> e-mail: k0od at mo.net
> -----------------------------
>
>
>
>From n3rr at cais.cais.com (Bill Hider) Sat Aug 5 22:36:51 1995
From: n3rr at cais.cais.com (Bill Hider) (Bill Hider)
Date: Sat, 5 Aug 1995 17:36:51 -0400
Subject: What's a dbworth?
Message-ID: <199508052136.RAA20144 at cais.cais.com>
I forgot to say that W6QHS ascribes a (theoretical) multiplicative factor of
1.17 (multiple of the number of times the station with 1dB more power will
be stronger than another station with 1dB less power) to 1dB.
It would be fair to call this = 17% .
Bill, N3RR
At 08:06 PM 8/4/95 -0500, Jeff Singer wrote:
> Articles often say that a mere db or two is not worth worrying
>about. That sentiment even appears occasionally in postings on this
>reflector. What is a single db--the basic molecule of a monster
>signal--really worth to a contester?
>
> Last year, I compared DX contest scores by power level: high, low and
>QRP.
>I concluded that increasing the transmitted power level a single db might
>increase a station's contest score by nearly 10%!
>
> My study took into account that 1500 watt stations usually have
>somewhat better antennas than 100 watters, which in turn probably have
>more aluminum than QRP stations. I compared the highest QRP score with
>the 3rd highest lowpower score and the 5th highest QRO score. I examined
>USA scores for contests over a 5 or 6 year period. In every contest I
>looked at, a single db was worth at least 6% improvement.
>
> Note that I am talking about a db increase in transmitted power. A db
>of antenna gain on transmit and receive should add more than 10%.
>
> I played around researching this for an hour or two. Has anyone ever
>done a real study of this topic?
> -----------------------------
> Jeff K0OD St. Louis, MO USA
> e-mail: k0od at mo.net
> -----------------------------
>
>
>
>From Greg Becker <gb546 at bard.edu> Sat Aug 5 22:43:09 1995
From: Greg Becker <gb546 at bard.edu> (Greg Becker)
Date: Sat, 5 Aug 1995 17:43:09 -0400 (EDT)
Subject: Windows 95
Message-ID: <Pine.A32.3.91.950805173927.32511A-100000 at core.bard.edu>
> Have any of those who have had the opportunity to use the beta copy of
> Windows 95 tried it's compatibility with the various contest programs? I
> understand that there is no real DOS prompt in Windows 95 and that it may
> not like programs like CT. It would be good to know before installing
> Windows 95 on your computer!
Yup. Ran CT 9.23 on FIeld Day under Win95, on an IBM (honest!) 486DX66
with 8 meg. Way I did it was to boot the machine from a Win95-created
boot floppy. This gives you a DOS-type prompt, then just ran TSRs & CT
from the prompt. Never had one glitch during the entire contest.
FYI - this was in the CW-only station at the Hudson Valley Contester's
and DXers / W2XL 3A effort in ENY. The K5NA fiber-optic interface worked
GREAT, as usual. We're going to miss him...
73, Greg NA2N
Greg Becker NA2N
gb546 at bard.edu
>From esteban at sefl.satelnet.org (Esteban J. Morao) Sat Aug 5 22:59:04 1995
From: esteban at sefl.satelnet.org (Esteban J. Morao) (Esteban J. Morao)
Date: Sat, 5 Aug 1995 17:59:04 -0400
Subject: No subject
Message-ID: <9508052159.AA14149 at prod1.satelnet.org>
I have a need Internet Address:
esteban at sefl.satelnet.org (Esteban J. Morao, YV5DTA)
73 from Steve W4/YV5DTA
esteban at sefl.satelnet.org
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