BEWARE: WR6R/KH7 NOT ON KURE
wv5s at icon.net
wv5s at icon.net
Tue Apr 2 21:11:08 EST 1996
Ed,
I don't know how you can guarantee that the log will be thrown out.
The KH7 series callsigns have been available for use in Hawaii for
over a year. This info has been published in every magazine I have
seen. Many Hams have used it including myself. I used NH7/WV5S in
the WPX CW Test last year and had my scores published in CQ Magazine.
It never hurts to check things out before you start calling people
names on the reflectors.
Jim, WV5S
> Date: Mon, 1 Apr 1996 10:35:16 -0800
> From: k4sb at ix.netcom.com (Edward W. Sleight )
> Reply-to: k4sb at ix.netcom.com (Edward W. Sleight )
> Subject: Re: BEWARE: WR6R/KH7 NOT ON KURE
> To: n0dh at comtch.iea.com
> Cc: CQ-CONTEST at tgv.com
> Well, technically, he has jumped the gun, and I agree with you
> entirely.
>
> WHEN the FCC starts the Vanity program, part of it will make KH7 a
> legal KH6 call. Same with KL7s.
>
> Always some jerk....let him live in his own misery. I think I can
> guarantee if he submits his log, it's going to be tossed.
>
> 73, Ed
>
>
>From Jim Reid <jreid at aloha.net> Tue Apr 2 21:36:54 1996
From: Jim Reid <jreid at aloha.net> (Jim Reid)
Date: Tue, 02 Apr 1996 11:36:54 -1000
Subject: A dB is a dB.
Message-ID: <1.5.4b12.32.19960402213654.006b14e0 at aloha.net>
At 13:56 4/2/96 EST, George Cutsogeorge wrote:
>
>Sorry, I can't take it any more.
>
>A 6 dB change in voltage IS a 6 dB change in power. If the
>voltage is doubled then dB(voltage)=20 log 2=6.02.
>
>And since power is proportional to voltage squared it goes
>up by 4 times and dB(power)=10 log 4=6.02.
>
>George, W2VJN.
Good for you George! This mistaken belief that a dB of voltage
is different from a dB of power was even a problem for guys when
I was in EE school! The dB was defined as a power ratio
by those who created the dB early on this century. And you
just did exactly as was done then
to illustrate their true sameness. A ratio is a ratio is a ratio,
just as " rose is a rose", and it IS by definition:
P = Esquared/R
dB gain = 10 times log Pout/Pin
dB gain = 10 times log Esquared out/Esquared in (note the R's in the
denominator have cancelled)
both E and P are measure across the same R in the above.
And as George points out above, the dB is defined as
10 times the log of the power ratios. Since power is
also Esquared over R, when one does logarithim arithmetic,
the exponent of a number in the ratio can come out in front
of the log representation as a multiplier, or in theis case
as 2. Since dB is defined as 10 times the log of the power
ratio, the 2 is multiplied by 10, and that is from where
the 20 comes in front of the log ratio when the ratio is
of voltage. It has to be there, since, by definition a dB
is a power ratio expresion!
By the way
it was at the Bell Telephone Laboratories back earlier in the
century when the Bel unit of power ratio measurment was originated;
then they introduced the deciBel, dB, to handle the variety of power
increments being encountered in the switched networks. The Bell Labs
guys used their founder's abreviated name for their unit of power ratio
measurment. That's why the B is always capitalized, a guy's name.
Why did they introduce a logarithmic ratio measure? To
make big ratios small, and small ratios big. For example,
1,000,000 becomes +60dB since 10 raised to the 6th power is
1,000,000, or 6 is the exponnent, and a logarithim to the base
10 is the number to which 10 is raised (or the number of
times 10 is multiplied by itself to yield the the original large,
or small number); and 0.0001 in dB is -40dB.
The Bell people went on the define 1 milliwatt of power as 0 dBm,
and 1 watt of power as 0 dBW (two guy's names, Bell and Watt, so originally
two capital letters!), or 1 watt can also be +30 dBm, and so forth.
And you don't want to hear about all the other dB units of mearuses used
in the telecom industry and cable industries today, dBricno, etc!
But still a dB is a dB is a dB, no matter what is being ratio'd.
Jim, AH6NB
jreid at aloha.net
More information about the CQ-Contest
mailing list