PWR
ames at force.DECNET.LOCKHEED.COM
ames at force.DECNET.LOCKHEED.COM
Fri Jul 15 16:10:52 EDT 1994
As another data point, since I usually operate low power and have not
even been concerned with the output of a linear (especially if > 1 kw),
even us little pistols get excied about power. A little over a year
ago I had a contest QSO with a Colorado station and over heard him in
the prior QSO mention that he had a TS830, same rig as mine. I sent a
QSL to confirm, and his QSL reply stated 200 watts SSB. This caught my
attention since I can't get anything over 100 watts out of mine. To
make a long story short, he was going by the old FCC rule of INPUT POWER.
Assuming it has a class AB amplifier, that all connects.
Point 1, a lot of people haven't read the FCC "regulations" in a few
years and are still talking about INPUT power rather than what is
going into the feedline.
Point 2, if people are running Gas/Soup/Nitro they may also assume
they are using Class AB1 or AB2 amplifiers. I remember back when I
studied for my Commercial licence, all that Hi-PWR stuff is Class C.
I think keeping your signal "clean" might be a potential problem.
73, alan N2ALE/6
>From S. E. Parker WA7VYJ <slp9m at cc.usu.edu> Sat Jul 16 01:05:11 1994
From: S. E. Parker WA7VYJ <slp9m at cc.usu.edu> (S. E. Parker WA7VYJ <slp9m at cc.usu.edu>)
Date: Fri, 15 Jul 94 17:05:11 MST
Subject: soup vs. gas
Message-ID: <AA4C7249 at Coquina.cass.usu.edu>
W0UN dixit:
> 3) And the regulation doesn't state
>what communicate means. Does that mean with lots of repeats and spelling
>things out phonetically, or does it mean that I can communicate even the
>nuances and subtleties in my voice? A lot of dBs between those two extremes
>of "communicate".
Going to the first of the aforementioned extremes and taking this rule in
isolation, fone would be outlawed all together. If you were "just making it" on
fone, you could always QRP a bit more and still cut it on CW. How would it be?
The codeless license debate would become totally moot and the USENET SNR might
even rise to a tolerable level. Not to mention a similar effect on all the ham
bands.
Seriously though, I wonder if there has ever been any enforcement of a rule so
subjective.
> A light just lit up over my head. No wonder all of us out west are getting
>beat in the pileups by the east coast. We are only running gas and they are
>running SOUP.
Makes you wonder about the analogy that spawned the term. Next time some east
coast type offers me a bowl of soup, I'll proceed with EXTREME caution.
73, -SEP
----------------------------------------------------------------------------
Scott E. Parker WA7VYJ
Center for Atmospheric and Space Sciences
Utah State University Logan, UT 84322-4405
Internet: sparker at coquina.cass.usu.edu sparker at cedar.hao.ucar.edu
Twisted pair: 801-797-2975 (USU) 801-797-2992 (FAX) 801-753-3924 (home)
>From ken.silverman at atlas.ccmail.AirTouch.COM (ken silverman) Sat Jul 16 01:12:41 1994
From: ken.silverman at atlas.ccmail.AirTouch.COM (ken silverman) (ken silverman)
Date: Fri, 15 Jul 94 16:12:41 PST
Subject: Passing Gas
Message-ID: <9406157743.AA774313961 at atlas.ccmail.airtouch.com>
Someone HAD to use this subject line...
While we are on the topic, It would be nice to confirm where our
1500w power limit is to be measured. Surely you say PA output
power. But is this at the back of the amp, or at the input of
the antenna?
How many VHF types use mast-mounted amplifiers to overcome feed
line loss? Most serious ones I know.
When running dual antennas, and dual amps, is 1500w allowed to
each antenna? You can build a 10dB omni (with *relative* ease)
on 10m, or you can build a 10dB gain yagi with a 54 degree lobe.
You can put 1500w into either. So whats the difference if I use
two 10dB yagis and 1500w to each => Same thing as the 10dB omni.
I personally think PA power gets lost in relation to ERP.
I guess my views are somewhat confused, for in my professional
life (cellular industry) everything is judged by ERP. I can run
100w and a 0dB gain antenna, or 1w with a 20dB gain antenna, and
still be within the letter of the law. Just maybe, ERP is the
great contest equalizer that people have been looking for! (save
the flames - I do NOT support equalization in any form - you can
have the best equipment in the world, but its the ops that makes
the difference) The idea sounded good in light of my rambles...
Food for thought.
CU Ken WM2C
ken.silverman at atlas.ccmail.airtouch.com
>From tree at cmicro.com (Larry Tyree) Sat Jul 16 00:05:48 1994
From: tree at cmicro.com (Larry Tyree) (Larry Tyree)
Date: Fri, 15 Jul 94 16:05:48 PDT
Subject: Not GAS
Message-ID: <9407152305.AA26903 at cmicro.com>
So, you all know about the NCJ articles showing how to match your 50 Ohm
load/transmitter to your 75 Ohm hardline you got for free from your
local CATV company. What? You don't?
Basically, you can take two equal lengths of 50 and 75 Ohm Coax, put them
in series, and by connecting the 75 Ohm side to your load/transmitter and
the 50 Ohm side to your hardline, achieve a perfect match. The length is
about .081 wavelengths (mind your velocity factors).
One idea I came up with is making your matching section out of 3 equal
pieces with either 50 or 75 Ohms in the center, and the other impedance
on the ends, then it is impossible to install it backwards.
Finally, I remember one of the NCJ articles saying that you can see why
this thing works if you use a Smith Chart. Since I work for a microwave
probing company that has Smith Charts everywhere, I finally got one
of the microwave engineers to work through the problem on a smith chart.
If you are interested in doing this for yourself, read on.
First, draw look at the following schematic:
TX ----- 50 Ohm -----|---75 Ohm---|---50 Ohm---|---------75 Ohm hardline
C B A
You start at point A. As you move back from point A, you are moving a 75
Ohm impedance to some other impedance as you move back to point B.
To do this on the Smith chart, normalize your 75 Ohm impedance that you
have at the right hand side of A (you are looking to the right from
the 50 Ohms side of the transistion into a 75 Ohm load). Since the
impedance of the line between B and A is 50 Ohms, then you normalize
the 75 Ohms to 1.5. Loacate 1.5 on the X axis (real) of your smith chart.
This should be near the center of the chart, just off to the right hand
side (1.0 is in the center).
Now you need to do the impedance transformation as you move from point
A to B. This can be done with a ruler. First it will be sitting along
the X axis. Notice the linear distance between the 1.0 mark and the
1.5 mark. Now rotate your straight edge .081 wavelengths (towards the
generator which is clockwise). Mark the point
along the straight edge that is the same linear distance from the 1.0 mark
(towards the bottom left of the chart). This impedance should be about
1.16 - j0.42 which if you multiply by the 50 Ohms we had normalized to
is 57.5 Ohms - j20 Ohms.
As we back away from point B towards point A, our reference is now 75 Ohms.
Renormalizing 57.5 Ohms - j20 for 75 ohms yields 0.767 - j.267. Now if
we rotate from that point 0.81 wavelengths like before, you should end up
near the X axis again with a reading near .67. When you unnormalize .67
(by multiplying by 75), you end up really close to 50 Ohms with no
reactance (since you are on the X axis).
If you follow this, you should be dangerous enough to do most any
impedance calculation using different lengths of different impedance
coax lines. As an exercise, you can verify the formula that lets you
match two impedances using a quarter wave matching section of an impedance
equal to the square root of the product of the two impedances you are
matching.
, then you rotate it with the center of rotation at 1.0 (the
center of the chart) and rotate it .081 wavelengths. Mark a point along
the straight edge that is as fra
>From tree at cmicro.com (Larry Tyree) Sat Jul 16 00:47:15 1994
From: tree at cmicro.com (Larry Tyree) (Larry Tyree)
Date: Fri, 15 Jul 94 16:47:15 PDT
Subject: Impedance matching
Message-ID: <9407152347.AA27281 at cmicro.com>
Sorry for the garbage and non signature at the bottom of my last posting.
Operator error!!
Ignore the garbage.
Tree N6TR
tree at cmicro.com
>From Robert Wood <w5robert at blkbox.COM> Sat Jul 16 06:38:24 1994
From: Robert Wood <w5robert at blkbox.COM> (Robert Wood)
Date: Sat, 16 Jul 1994 00:38:24 -0500 (CDT)
Subject: tower/antenna
Message-ID: <9407160038.aa14630 at blkbox.COM>
Looking for advice from someone who has loaded up
a Crank-up tower on the low bands. I have attempted this
but had problems loading it and getting out. (Also) It is
ungrounded at base or the June issue of QST would be a
great guide. I do have antenna tuner available.
73 Robert WB5CRG w5robert at blkbox.com
>From Kenneth G. Kopp" <0006485696 at mcimail.com Sat Jul 16 07:12:00 1994
From: Kenneth G. Kopp" <0006485696 at mcimail.com (Kenneth G. Kopp)
Date: Sat, 16 Jul 94 01:12 EST
Subject: GAS
Message-ID: <52940716061225/0006485696PK4EM at mcimail.com>
Hummmmm ... I thought the word was SMOKE ... 73! de Ken K0PP
>From Mr. Brett Graham" <bagraham at HK.Super.NET Sat Jul 16 13:49:35 1994
From: Mr. Brett Graham" <bagraham at HK.Super.NET (Mr. Brett Graham)
Date: Sat, 16 Jul 1994 20:49:35 +0800
Subject: VS6BG IARU results
Message-ID: <199407161249.AA10331 at hk.super.net>
Single-op CW-only
Qs Qpts Zs HQs
160 1 1 1 0
80 9 27 4 0
40 73 249 14 2
20 112 412 21 11
15 152 534 18 10
10 9 25 3 0
Total: 356 1248 61 23 for 104K
Time spent in front of rig - <10 hours. Worked W5WMU only on 40. He was the
strongest stateside heard here on 20, but he couldn't hear me. Local QRN, QRM
on his side, one-way propagation or gas? Since he answered first call on 40,
I'd say one of the first two. Admittedly, power is a problem everywhere, but
from out here, it's worse from EU, though the JAs are gaining (obvious in DX
pile-ups - I'm not sure if the same stations are active in contests).
73, VS6BrettGraham aka VR2BG bagraham at hk.super.net 1015z 16 July 94
>From Doug Grant <0006008716 at mcimail.com> Sat Jul 16 15:29:00 1994
From: Doug Grant <0006008716 at mcimail.com> (Doug Grant)
Date: Sat, 16 Jul 94 09:29 EST
Subject: High Power
Message-ID: <32940716142923/0006008716NA4EM at mcimail.com>
This has been an interesting thread. I got a lot of (apparently) direct mail
asking specific questions (MCI Mail's gateway is now stripping the headers,
so I can't tell if the comment appeared on the full reflector or not).
I'd like to answer a few of the more interesting ones here (with attribution
anonymous...).
1. "Why didn't you just turn the power down to 1500W?"
Actually, Trey answered this one before I could - I was a guest, and the host
was quite proud of his big amp ("Just wait 'til you get on *this* band!"). I
had no other options for the weekend, and decided to make the best of a bad situation.
And the amp *was* big. I don't know how much power it ran, but it needed an
SB-200 for a driver between the rig and the final (I have heard this as a joke
from time to time, but I've atcually seen it!).
As I mentioned in my original post on this thread, I have been invited to operate
numerous times at stations widely believed to be running high power. I really
don't care if they do it or not, but my call will never be associated with this
practice (except for that one time a long time ago - in fact, I don't think
my call ever showed up in the op list...).
2. "...but did you inhale?" (from about 10 of you!)
I guess it sounds kinda Bubba-like, doesn't it? Now I have a bit more sympathy
for the Bubba-bashing that went on during the campaign. Oh, well.
I will admit that the rates were pretty good, and I don't recall getting beat
in a single pile up on the big-box-band. But my ethicsand pride in my reputation
have long since overcome the feeling of machismo from that weekend. I'm more
interested in mastering two-radio use now than paying an electrician for
3-phase service.
3. "Have you ever operated from here in -------? We *need* high power to
compete" (from a few geographies!)
Guess there's all kinds of ways to rationalize illegal behavior. Maybe I
should try big power in the SS...everyone knows you can't compete in SS from
W1.
THis goes back to the equalization (please - not again) debate.
IF you are propagationally or finanacially or monetarily challenged, then
you should consider legal ways of overcoming those limitations. Oops...change
that "monetarily" to whatever you feel your disadvantage is.
4. "I thought it was SOUP, not GAS"
Soup, gas, smoke, flames, smash...use whatever word you feel most comfortable with. Or uncomfortable if it's hung on your call.
5. "How much power is high" (several)
Everyone has their own interpretation (and rationalization for it). I need
3 dB more 'cuase I have long old coax. I need 3 dB more 'cause there's a hill in the
way.
Sorry. My feeling is that there a few commercial amps that cross the line, but
not many. A homebrew amplifier built for the express purpose of running more
power than something commercial is out of bounds. If you run one of these,
don't invite me over to operate.
Anything using an Eimac tube with more than 4 digits in the suffix is out of bounds. By a lot.
I'm not so manic about this that I look carefully at the wattmeter and crank
it down if it ever goes over 1501 watts. I try to use common sense.
6. "You W1s don't understand high power because you don't need it" (from a
K5 now in W1...)
Maybe I ought to drop by his place and see if he brought his K5 amplifier with
him to W1! (Just kidding...but it'd be a great rumor to start!).
INteresting thread. Hope someone send a complete copy to W5WMU and whoever
else they
suspect of running high power...
73,
Doug K1DG
k1dg at mcimail.com
>From John W. Brosnahan" <broz at csn.org Sat Jul 16 15:41:54 1994
From: John W. Brosnahan" <broz at csn.org (John W. Brosnahan)
Date: Sat, 16 Jul 1994 08:41:54 -0600
Subject: W0UN's final FINAL posting
Message-ID: <199407161441.AA18861 at teal.csn.org>
One last reference to the history of Big Gas. I knew that the two references
that I cited yesterday were not the ones I was looking for so I persisted
and found the original article by W0SYK on a pair of 4-1000s. 73 Magazine
for May 1965 had on its cover a list of featured articles which includes a
"5000 Watt Linear!" in 1/4" high letters. In the index it is referred to as
"THE BIG BOMB Runs a gentleman's gallon". I don't think any of the U.S.
amateur magazines of today would run an article like this, or feature it
on the cover, so I suggest that running high power was more blatant
25 and 30 years ago than it is today. (Note: I said blatant not common,
since I can't speak to the number doing it then or now, only that it was
more open in the past.)
John W0UN broz at csn.org
>From Wayne Mills <0006509309 at mcimail.com> Sat Jul 16 18:20:00 1994
From: Wayne Mills <0006509309 at mcimail.com> (Wayne Mills)
Date: Sat, 16 Jul 94 12:20 EST
Subject: Centrate?
Message-ID: <24940716172042/0006509309NA4EM at mcimail.com>
Centration? That does it! Come on guys, get a life (and learn the
language)!
UNSUBSCRIBE!!
N7NG at MCIMAIL.COM
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