Experience with SGC ?
Gerald Schmitt
Has anyone any experience with the SGC QMS system? I was
going to built one but recent experience has put me off
for the moment.
For some time I have owned the SGC-230 tuner. At a hamfest
over the weekend I acquired the SGC-303 antenna with the
insulated spring and ratchet mount.
Now I had most of a QMS system so I gave SGC a call to ask
about buying the tin box to put the tuner in and complete the
QMS system.
Keeping in mind that the tuner lists for $595, the antenna
system lists for $495, and the entire QMS system has been on
"special" for $895 for the past year; how much could the tin
box be worth? I don't know how much it is worth but it costs
a whopping $490.
Considering what I have heard from the California Shoot Out
it may not even be worth pursuing the SGC system but the auto
tuning is attractive on long hauls. I am particularly interested
in a system that can move from vehicle to vehicle without scuffing
up the finish. Any input will be greatly appreciated. Any input that
precludes paying SGC exorbitant prices will be particularly
appreciated.
cmo...@sedona.intel.com
Gerald Schmitt <g...@aerie.lanl.gov> wrote:
>Considering what I have heard from the California Shoot Out
>it may not even be worth pursuing the SGC system but the auto
>tuning is attractive on long hauls.
I am under the impression that the Shoot Out was on 75m, a band that
Mother Nature never intended to be used mobile. :-) The Shoot Out would
probably have a different outcome if it were done on 15m. I don't know
anything about the QMS antenna. I use the SGC-230 and a 13 ft whip for
multi-band operation 10m-20m. The longer-than-quarter-wave length on
10m-15m gives it gain over a bugcatcher which has been verified by field
strength measurements. It is one 'S' unit down from a bugcatcher on 40m.
W5GYJ uses a bugcatcher with an SGC-230 and puts out a heck of a signal.
The advantage of such a system is the antenna only needs to be close to
resonance so the entire band is always available and the bottom matching
coil can be eliminated.
73, Cecil, KG7BK, OOTC (not speaking for my employer)
Bill Harwood
excellent luck using the 230 with Hustler and Pro-AM multi-band
antennas. The 230 provides the band width to allow changing frequencies
without adjusting the tuning. The best performer though is an 230 with
a SPIDER top loaded antenna. It will exceed the performance of anything
in the shoot out on all bands except 80. On 40 it is about par. The
Navy did a lot of research in the 50's and 60's which proved that top
loading is the best for a short antenna. One place I do use the SGC303
is for off road 4X4 work. I have a quick mount on my SPIDER and 303.
When I leave the pavement I pull over and switch antennas. The mutiband
loaded ones are just too heavy to ballance around and survive.
Good Luck,
Bill Harwood
AB6DY
Gerald Schmitt
Cecil,
Thanks for the input re: the SGC tuners. I have used the tuner with
good results at home with a long wire and ground. I became more interested
in the mobile performance last weekend when I was able to buy a SGC-303
antenna mast with the spring and mounting bracket at a hamfest.
Having most of the QMS system I thought I'd just give them a call and
buy the tin box to complete it. For a tin box with a few connectors
four suction cups and some nylon straps $490 I told them I already had
the tuner they assured me that was just for the empty box. At that
point rethinking the plan seemed in order. I like the tuner but
can't say too much for the company. I tried to fax the CEO and some
sales hack intercepted my fax so much for that approach.
Any way thanks for your thoughts other input is mostly negative so
I will have to consider what to do now.
Garry Foster
Cecil
The above is a very important part of a base mounted tunner. Many of our
experts seem to fail to grasp the importance/convenience of this. This
type of tunner has been used on aircraft for years. And if one is a
camper another 20 feet of wire tied from the whip to a tree makes a
"Pretty Good" Low band antenna.
73 Garry WB0NNO
Garry Foster
On Fri, 28 Jul 1995 arm...@delphi.com wrote:
> Garry Foster <gmfo...@epix.net> writes:
Well Sir I didn't write the statement below. It was part of a message
that I quoted. I'm not sure I'd agree with your statement about 75 being
the most popular mobile band though. Most times that I listen to 75, I end
up being somewhat ashamed to be a ham. It is a wonderfull piece of
spectrum which is abused by more than a few. And as in anything else
there are many fine gentlemen found there which is why I'm in the process
of buildinf a screwdriver antenna. Besides I can't afford a SGC set up.
73 Garry WB0NNO
>
> >> I am under the impression that the Shoot Out was on 75m, a band that
> >> Mother Nature never intended to be used mobile. :-) The Shoot Out would
>
> Then why do you suppose that 75 is the most popular mobile HF band. Why did
> they choose this band??????
>
>
cmo...@sedona.intel.com
KG7BK> I am under the impression that the Shoot Out was on 75m, a band
KG7BK> that Mother Nature never intended to be used mobile. :-)
>Then why do you suppose that 75 is the most popular mobile HF band. Why did
>they choose this band??????
Probably for the same reason CW is still a requirement. :-) Some hams
love to live in the past. IMO, it is illogical to deliberately choose
a band for mobile operation where the ground-loss resistance is ten
times the radiation resistance. IMO, the higher bands are better
candidates for mobile operation. For me, 75m mobile is a last resort,
sometimes (but not always) a slim donut between mountain-top repeaters
and 40m mobile. Would you object to a shootout on 15m and if so, why?
arm...@delphi.com
>> I am under the impression that the Shoot Out was on 75m, a band that
>> Mother Nature never intended to be used mobile. :-) The Shoot Out would
cmo...@sedona.intel.com
>Cecil: SGC makes the following claim (quote) " You can get more than 20 dB
>of gain by simply using an SGC compared with any other 1.8 to 30 MHz system."
If they really said that, it is, of course, absurd. I have said it before,
I have almost everything they have published and I am unable to verify
the above quote. The closest thing I can find in what they sent me is
the statement that their system will perform better than a conventional
nine ft. whip. Worldradio has stretched the truth so often that I will
believe it when I see it with my own eyes. How about FET finals re-
reflecting all the reflected power but bipolar finals being destroyed?
arm...@delphi.com
>believe it when I see it with my own eyes. How about FET finals re-
are you going to say after your read with your own eyes?????? Do you have a FAX,
I'll send it to you you will read in really big lettering these two phrases:
"SGC's 20 dB Advantaghe with QMS" and "20 dB GAIN USING QMS!"
cmo...@sedona.intel.com
>Also, I think they are looking for local area
>work..road conditions, weather, restaurants, hotel info and chatting with
>friends, etc.
In AZ and CA 2m works best for this type stuff. One will radiate more
RF from a 40w 2m mobile that from a 100w 75m mobile. If we could get
all the mobiles off 75m and onto the more efficient 2m, the universe
would not run down quite as fast. :-)
>Do you believe that on 15, the SGC claims of 20 dB gain over
>ANY other system would be valid?
What I believe is that SGC never made that claim. Fortunately,
Mother Nature doesn't care what I believe, what you believe that SGC
has claimed, or what SGC has actually claimed. My 13 ft whip fed with
the SGC-230 outperformed an 8 ft bugcatcher on 12m and it doesn't matter
what your alleged omniscient writer for Worldradio thinks. (Remember,
you said he never makes mistakes).
Ross Alexander
>In article <JRBjRhD...@delphi.com>, <arm...@delphi.com> wrote:
>>Then why do you suppose that 75 is the most popular mobile HF band. Why did
>>they choose this band??????
> [...] IMO, it is illogical to deliberately choose a band for mobile
>operation where the ground-loss resistance is ten times the radiation
>resistance. IMO, the higher bands are better candidates for mobile
>operation. For me, 75m mobile is a last resort [...]
The reason 75m is an interesting mobile band is that it's a tough one
to do right. One pleasant part of the ham experience is to
deliberately accept a handicap, such as this problem of radiation
efficiency, and to overcome or work around it. I've worked 75m
mobiles (on phone) over ~4000 km paths and in doing so I felt both a
sense of accomplishment and of admiration for the other fellow's skill
in building such a excellent mobile rig; my hearing him was no special
trick (500' beverage) but him hearing me was most remarkable.
regards,
Ross ve6pdq
ps: oh, and I picked up a new state (Florida) as a bonus.
--
Ross Alexander, ve6pdq -- (403) 675 6311 -- r...@cs.athabascau.ca
Gerald Schmitt
Cecil,
Re: SGC's absurd claims. Read any of their "Learn to love the look"
ads. If you want more send me a fax number they indeed make all of
the claims attributed to them in the literature. When Kurt N Sternba
took them to task he quoted their claims accurately.
When they sent me a fax it had a copy write note and a non disclosure
statement on it. When have you ever seen such nonsense. SGC makes a
good tuner but other than that they are a bullshit outfit. Remember
this is the outfit that brings you the $490 tin box.
As to using 75 as a shoot out band it makes sense to me. To compare
systems pick the most difficult problem. Radiating on 10 12 15 is
no challenge as any truck driver. Seventy five separates the claims
from the SE units.
73 de Jerry
cmo...@sedona.intel.com
Gerald Schmitt <g...@aerie.lanl.gov> wrote:
>Re: SGC's absurd claims. Read any of their "Learn to love the look"
>ads. If you want more send me a fax number they indeed make all of
>the claims attributed to them in the literature. When Kurt N Sternba
>took them to task he quoted their claims accurately.
Hi Gerald, it is a typical ploy of Kurt N Sterba to twist what one
says to fit his purposes. If you will look back at the original
postings, I did not defend SGC's claims and said that their claims
were marketing hype. What I objected to was the statement by Kurt
that a mobile antenna never has an SWR higher than 4:1. At the
time he said it, my CB whip on 20m was running 20:1. That statement
about mobile antennas was what I took exception to, not the SGC
claims. I can't find the particular issue so let me repeat what I
remember. Kurt said something to the effect that a base-mounted
antenna tuner was unnecessary since the typical mobile antenna never
has an SWR higher than 4:1. My point was, who said anything about
typical mobile antennas? A base-mounted antenna tuner allows
atypical mobile antennas with some pretty neat characteristics.
The subject was changed by someone leading us down a primrose path
to divert attention from Kurt's original mistake which concerned
generic base-mounted antenna tuners, not SGC. This thread is way
off the original subject and IMO, it's not by accident.
Kurt, here's a simple yes/no question for you. Can a mobile antenna
have an SWR higher than 4:1? If you say no, you have repeated
the mistake you made in your column. If you say yes, you need to
correct the mistake you made in your column. The mistake you made
had little to do with SGC. IMO, you changed the subject to cover up
your mistake and hoped we would forget the original subject.
Again, I am not defending SGC's marketing hype. My objection was
that some hams will believe Kurt's poppycock that mobile antennas
cannot have SWRs higher than 4:1 and may pass up a base-mounted
antenna tuner that would be ideal for their mobile applications.
IMO, Kurt (through his one friend :-) twisted the subject of conversation
away from the mistake he made so he could continue to appear omniscient.
I appologize for allowing his ploy to work but he is a master at it.
Kurt, have you ever made a mistake in your column? If you answer no,
we will know you are an omniscient being. If you answer yes, did you
admit it and correct it?
Gerald Schmitt
Cecil,
I must have missed some of the thread. I still think 75 was a
good test because of the problems faced. I will have to read the
KNS column again about the SGC hype.
An interesting thing gleaned from the SGC fax was that they are
going to Japan for a show and to a boat show but have given a
pass to the two major hamfests in Oregon and Washington during
the past few months. I don't think SGC can tolerate too much
technical scrutiny.
As an exercise for the student, and because I have the antennas
available, I am planning on mounting the SGC, a bug catcher style,
and a Don Johnson screwdriver on the same vehicle with a coax
switch. This should be enlightening.
arm...@delphi.com
>nine ft. whip. Worldradio has stretched the truth so often that I will
antenna used on 20 or some such stuff that was never said in the article. I
tried to pin you down about it and your answer was that you didn't have the
article but that's what you think it said. I would examine that statement of
yours about "Worldradio has stretched the truth so often". You had best have
some actual data to back that up. I have printed out your dispute on the FETs
and
will contact the author for clarification. That may be a technical mistake
but does not fall in the area of "stretching the truth" you are being asked
tyo defend your use of the statement "SO OFTEN"...Say, didn't you end up
having to apologize to Maxwell, too? Is this some sport that you enjoy?
arm...@delphi.com
>were marketing hype. What I objected to was the statement by Kurt
>that a mobile antenna never has an SWR higher than 4:1. At the
said "A mobile antenna never has an SWR higher than 4:1" You have repeatedly
made that statement on this forum. It is now time for you to PROVE IT. Since
I went and found the column you talk about it, and have it in front of me,
all I can say is you are going to feel very sheepish when you have to
apologize to all concerned. I have tried to save you the embarrasment on
several occasions by telling you that what you state was never said.No one
else thinks that article says that, except YOU!
cmo...@sedona.intel.com
>Kindly type on to the screen for all concerned when and where Sturba ever
>said "A mobile antenna never has an SWR higher than 4:1"
I waded through back issues of Worldradio at Ft. Tuthill and I couldn't
find the article. I admitted I was doing this from memory and asked for
your help in resolving the argument. So far, you have refused. How about
you tell me what issue it was in so I can order a replacement and either
defend my position or admit I was wrong?
Cecil A. Moore -FT-~
><cmo...@sedona.intel.com> writes:
>That may be a technical mistake
>but does not fall in the area of "stretching the truth"
We appear to be from different planets. A "technical mistake" is much
worse than "stretching the truth". If I pour through *any* hamradio
magazine, I can find multiple examples of statements that are not 100%
true. If a statement is completely wrong, it is a mistake. If it is 1%
wrong, it is "stretching the truth" and it happens multiple times every
month in every hamradio publication. A simple statement like, "For ALL
intents and purposes, this (the impedance of free space) is equivalent
to ... 377-ohms." should have been "For MOST intents and purposes..."
Using the word "All" in that context is likely "stretching the truth".
>Say, didn't you end up
>having to apologize to Maxwell, too? Is this some sport that you enjoy?
You are just proving my point. Mr. Maxwell apologized for any statements
in "Reflections" that might have mislead anyone to believe that he implied
that reflected power is 100% re-reflected in a non-conjugately-matched
system. I apologized for using his name in the thread title which, by
the way, was not a statement but the rhetorical question, "Was Maxwell
Wrong?" I didn't believe he was wrong, and it turns out, he wasn't
wrong. Some people had wrongly interpreted what he had written.
In attempting to shine the light of truth, anyone (excluding omniscient
antenna experts) may make mistakes, including me.
Joanne Dow
Just to throw some interesting monkeywrenches into the discussion I remember
back in 'bout '72 I ran across an study at Rockwell (either from the Collins
plant in Cedar or Bendix in Ma) analysing base matching a vertical whip antenna
for backpacks. With componentry available at that time they concluded that for
a whip resonant at about 80MHz you could get just about as good VSWR and
radiation over the 30MHz to 80MHz range by tossing a 50 ohm dummy load at the
base of the antenna as compared to any reasonably pack mountable tuning
apparatus. The coils of such size as to fit in even a BIG pack radio simply had
such a great loss that base loading a whip introduced so much loss you might as
well feed a dummy load with a pigtail on it. I suspect the conclusion applies
to a 9' whip on a car bumper with any matching unit about the size of the SGC.
It'd be interesting to find out.
Of course anybody with any good sense and a desire to only work one band uses a
center loaded antenna with as big a top hat as manageable. The base tuner would
be used only to fine tune the VSWR as you change frequencies.
It's such fun to toss out these little pearls you run across over a 30 year
career.
{^_-} Joanne Dow The Wizardess
cmo...@sedona.intel.com
>Kindly type on to the screen for all concerned when and where Sturba ever
>said "A mobile antenna never has an SWR higher than 4:1"
-start of letter written in mid-Sept, 1994_
Subject: Oct. '94 Aerials
I, too, saw the $900 mobile antenna tuner plus vertical. It appears to
me that there is no loading coil so it makes no sense to talk about a
maximum SWR of 4:1 - try 400:1. Assuming the vertical is an 8-ft whip,
ELNEC says the impedance on 20m is about 5-j500 plus about 5 ohms ground
loss yielding a calculated SWR of around 500:1 with 50-ohm coax. Assuming
10 ft of RG-213, the losses in the coax calculate out to be over 7 db,
not the neglible value that Kurt would have us believe. The antenna tuner
at the base of the antenna instead of 10 ft away has given us about an
'S' unit better performance, not neglible in my opinion.
In an earlier article, Kurt said that a square antenna is always better
than a dipole. I challenged him to come up with a square that will
outperform my 88ft dipole on 20m *and* 17m (2 lobes@9dbi and 4 lobes@
8dbi respectively). I haven't heard anything from him.
-end of letter-
If I had received a response in my SASEs, I would not have posted here.
I am ordering a copy of the Oct. 94 issue and will appologize if Kurt
didn't make misleading statements that prompted the above letter.
He lampooned me in 3 inches of a later column. He didn't mention the
technical topic. He simply attacked my choice of words and the fact that
I'm not a member of the IEEE. I think that qualifies as ad hominem.
In the meantime, since Kurt is such a nice fellow, how about if you post
the date of the issue in which he apologized for a single mistake.
cmo...@sedona.intel.com
>I would examine that statement of
>yours about "Worldradio has stretched the truth so often". You had best have
>some actual data to back that up.
Since you insist :-) Kurt N. Sterba said that a square antenna is
always better than a dipole. That was great news to me. I run a 5/4
wavelength dipole on 20m. It gives me 9dbi lobes into Africa and
Australia on 20m over real ground according to ELNEC. It also gives
me 8dbi lobes into Europe, South America, New Zealand, and the Pacific
Rim on 17m. Try as I might, I could not model a square antenna better
than that. I wrote to Kurt to find out the details on such a square
antenna. I received no answer so here is a public request to prove that
his statement was not BS. Please ask him what the design details are on
a square antenna that has better than 9dbi gain on 20m *and* better than
8dbi gain on 17m with world wide coverage on two bands without rotating.
Thanks very much, Cecil, KG7BK, OOTC, (not speaking for my employer)
Jan Anker
>From: Gerald Schmitt <g...@aerie.lanl.gov>
>Subject: Re: Experience with SGC ?
>Date: Sat, 29 Jul 95 07:42:41 mdt
>. SGC makes a
>good tuner but other than that they are a bullshit outfit. Remember
>this is the outfit that brings you the $490 tin box.
The device was develloped and is made by a Taiwanese co. called Ranger
and was offered in qts for usd 250 some years ago under Ranger RF products
type RA-2300 (there comes sg230 from).
So SGS seems to do only Marketing & Sales.
Ranger is specialized in CB equipment.
Bart Rowlett
>
>>> I am under the impression that the Shoot Out was on 75m, a band that
>>> Mother Nature never intended to be used mobile. :-) The Shoot Out would
>
>they choose this band??????
160 and 75 meters are the only bands where a large difference exists between
so called 'high performance' mobile antennas and the run of the mill Hustlers
and Hamsticks. The goal of the shootout was to demonstrate the ranking of
performance between the commercially available antennas and what you can
reasonably homebrew. 75 meters was chosen because it's by far the most
popular HF mobile band for the particular group of hams who conspired
to make it happen. The instrumentation used was designed to work well from
around 1 MHz up through 10 MHz and may well make an appearance at a
160m shootout if enough interest develops.
bart wb6hqk
Cecil A. Moore -FT-~
>I would examine that statement of
>yours about "Worldradio has stretched the truth so often".
Hi Armond, I think it's pretty obvious that I meant to type "Sterba"
instead of "Worldradio". I certainly didn't intend to criticize the
entire magazine, just one of the authors. This is a public apology
to anyone who thought I was slamming "Worldradio" in general.
"Worldradio" is a quality publication and I recommend subscribing
to anyone interested in ham radio. I certainly subscribe. "Worldradio"
is one of the better ham publications.
Lest you think the other publications escape my scrutity, "Radio Fun"
had an antenna article which said that the G5RV is not a dipole. I
responded with a letter and they responded with a letter. Case closed.
One of the problems is that K.Sterba is so inaccessable. Wonder if
he has ever considered getting an Internet account?
73, Cecil, KG7BK, OOTC (not speaking for my employer)
arm...@delphi.com
>find the article. I admitted I was doing this from memory and asked for
>your help in resolving the argument. So far, you have refused. How about
resolving the argument and where I refused....Please print that out.
The article I think you may be talking about was in the october issue
of 1994 page 95. How long will we have to wait for your contrite and
sheepish apology. By the way, I mailed to you, today, a photocopy of the
SGC 20 dB stuff......I talked to a leading authority on mobile antennas
over the weekend and he said that he doubted in would beat by 20 db a
string that had been soaked in salt water.
cmo...@sedona.intel.com
>Huh? Huh? I'd really like to see where you ever asked for my help in
>resolving the argument and where I refused.
Armond, we are obviously caught in a hopeless internet delay loop and
replying to old messages instead of the latest ones. I asked you what
issue the particular column was in and you were unresponsive until now,
probably through no fault of your own. I think your delphi postings
go all the way to Boston before they are posted. Mine probably have
to go all the way to Boston before you get to see them.
>The article I think you may be talking about was in the october issue
>of 1994 page 95.
Thank you. This is the information I requested. I will order a copy today.
>How long will we have to wait for your contrite and sheepish apology.
It's up to you guys. You'll have a $2 money order in a couple of days.
Let me repeat from memory: I think Kurt said (in so many words) that
using a base mounted antenna tuner was unnecessary because the average
mobile antenna has an SWR of less than 4:1 so the losses in the coax
do not justify a base mounted antenna tuner. My letter to him suggested
that the QMS antenna system, *which he was discussing in context*, would
have a much higher SWR than 4:1 and very high losses in any coax used to
feed it and therefore, a base mounted antenna tuner is justified for that
type system. Of all the many letters I've written to ham radio publications,
Kurt is the only person who has never answered. Does he ever respond to
your customer's letters? I started out with very respectful letters to
him and got no responses. Only after that did I adopt the squeaky wheel
approach.
>By the way, I mailed to you, today, a photocopy of the
>SGC 20 dB stuff......
SGC sent me a lot of stuff. I assumed it was all they had. The claim
of 20db over "any" antenna was not in the stuff they sent me. They
do claim a 3-6db advantage over a "conventional 9 ft. whip". Remember
I said their advertisment was marketing hype. My point is we shouldn't
throw out the baby with the marketing hype. No matter what the
advertising says, there are applications for base mounted antenna
tuners. There are mobile antennas with SWRs higher than 4:1. Whips
longer than 1/4 wavelength are excellent 10m-15m antennas.
>I talked to a leading authority on mobile antennas
>over the weekend and he said that he doubted in would beat by 20 db a
>string that had been soaked in salt water.
One time on field day, I strung up an end-fed antenna tied to a string
with no insulator which was tied to the top of a tree. I got out a lot
better after it rained.
arm...@delphi.com
>entire magazine, just one of the authors. This is a public apology
>to anyone who thought I was slamming "Worldradio" in general.
it was received and accepted. Your material re: the points you have raised
on antennas has been forwarded and you will receive an answer. On the FET
material your query will be forwarded to the original author and he will
be asked for an explanation. regards.
arm...@delphi.com
>Let me repeat from memory: I think Kurt said (in so many words) that
words" and you putting in QUOTE MARKS around statements. When you put the
quote marks around a phrase that means (no paraphrasing) but the exact,
again EXACT verbatim words used. Alas, much to our chagrin Kranky Kurt
answers almost no letters. Your two dollars will be refunded when it arrives.
We don't wish to add injury to....whatever.
arm...@delphi.com
>One time on field day, I strung up an end-fed antenna tied to a string
>with no insulator which was tied to the top of a tree. I got out a lot
>better after it rained.
I believe it.
cmo...@sedona.intel.com
>There may be the problem. There is a great gulf between, "said in so many
>words" and you putting in QUOTE MARKS around statements. When you put the
>quote marks around a phrase that means (no paraphrasing) but the exact,
>again EXACT verbatim words used. Alas, much to our chagrin Kranky Kurt
>answers almost no letters. Your two dollars will be refunded when it arrives.
>We don't wish to add injury to....whatever.
Unless I can't remember how senile I really am, I don't put quotes
around anything I'm not looking at while I type it in. I put quotes
around some of the SGC stuff and around the FET/Bipolar stuff because
I was looking at it at the time. When I say that Kurt said something,
without quotes, I am obviously inferring what he said. When he said
that a square is always better than a dipole, I inferred that he really
meant to say that a full-wave square is always better than a half-wave
dipole, and if so, he didn't write what he meant to say. Now there may
be a lot of young/new/non-technical hams out there who believe all
squares are better than all dipoles because of what Kurt wrote.
>>One time on field day, I strung up an end-fed antenna tied to a string
>>with no insulator which was tied to the top of a tree. I got out a lot
>>better after it rained.
>
>Ah, you are a true antenna magician since rainwater in non-conductive. But,
>I believe it.
What you don't know is the string had accidentally been soaked with
salt water draining off an ice cream maker the night before.
cmo...@sedona.intel.com
>There may be the problem. There is a great gulf between, "said in so many
>words" and you putting in QUOTE MARKS around statements.
Armond, I just re-read the entire thread and nowhere did I put "QUOTE
MARKS" around anything that wasn't a direct quote. I put no quotes around
anything that I recalled from memory, including anything about Sturba.
Perhaps it was your own initial use of quotation marks that is confusing
you.
From *your* posting:
>Kindly type on the screen for all concerned when and where Sturba ever
>said "A mobile antenna never has an SWR higher than 4:1"
Sometimes the attributions get mixed up and/or confused. I did not
commit the act you say I did.
PTracy
time to be blown down again this comming hurricane season or winter.. I
miss it. Tired of the 'standby' tribander that's been up there for 5+
years. What I am looking for is either some ideas, suggestions or
references on feeding the driven elements. The quad will be the standard
10-15-20 meter deal without Warc bands. The original design used a simple
feed method where all three loops were simply tied together and feed
through a balun. SWR performance wasn't what I would call spectacular. I
do have Bill Orr's book on quads, and one method he uses a tri-gamma
matching method that while it does look good electrically, mechanically it
seems to leave alot to be desired. Also, the need for variable capacitors
(4 total) is most un-appealing. Anyway, I have some time, this isn't
something going up next weekend so I do want to take my time with this and
do it right. What's your ideas?
BTW, one thing I remember about the quad is that it was seemingly immune
to precipitation static. I can remember hearing significantly increased
static / noise levels while it was either raining heavily or snowing on
the yagi. I do remember this did not happen to the quad. Any quad users
out there noticed that?
cmo...@sedona.intel.com
>What's your ideas?
This is an idea with questions attached and I don't know the answers.
Since the quad section one chooses is low impedance and therefore, low
voltage, can the switching be accomplished by relays? Is it possible
to shield/decouple the relays so they are immune to RF effects and can
be operated by DC pulses on the transmission line?
>BTW, one thing I remember about the quad is that it was seemingly immune
>to precipitation static. Any quad users out there noticed that?
In a dipole and transmission line, there is generally no DC path between
the poles hence static buildup. In a quad there is a DC path between
the transmission line conductors so static discharges. With a 4:1 balun
on my dipole, there is also a DC path through the balun and therefore
static discharge. It was an unexpected bonus when I installed the balun.
cmo...@sedona.intel.com
>Some point in the spectrum. I thought we had to stay in the amateur bands.
Hi Armond, it occurred to me last night after my posting that you and
I could be suffering from language problems. Unfortunately, I learned
my English in Texas (some say they don't speak English in Texas :-)
I was speaking in the context of the HF amateur bands. Here's how their
claim could be true. Compare the QMS antenna system with a "conventional
9 ft whip" on 30m. Use my IC-725. I have no doubt that the QMS system
will radiate 20 dB more RF than the barefoot IC-725 because of foldback.
Admittedly, I am playing devil's advocate. I am not defending their claims.
I am demonstrating how they may be rationalizing their claims.
My native Japanese friends will never understand the difference between
"can" and "will". Compare the following two statements:
I can die tomorrow. Obviously true
I will die tomorrow. Probably false, hopefully I am mistaken.
SGS didn't say the QMS system "will" make a 20 dB difference. They
said it "can" make a 20 dB difference, given a certain set of
circumstances, which they enumerated. We all know that they exaggerated
the effects of the items they listed and it is not likely that all
the items would ever exist in unison. They may have meant to convey
the impression that the QMS system is 20 dB better, but they didn't
say it "will" improve things by 20 dB.
All I'm asking is that Mr. Sterba take the time to insure that the
statements he makes and the quotes he uses are 100% accurate except
for unintended mistakes. When he throws out the bath water, how
about him mentioning that the baby wasn't also thrown out.
73, Cecil, KG7BK, OOTC
(100% all my own fuzzy logic, not speaking for my employer)
PTracy
writes:
>This is an idea with questions attached and I don't know the answers.
>Since the quad section one chooses is low impedance and therefore, low
>voltage, can the switching be accomplished by relays? Is it possible
>to shield/decouple the relays so they are immune to RF effects and can
>be operated by DC pulses on the transmission line?
>
This may be possible, haven't ruled it out. I have learned over time that
the selection of a good relay is no simple task. I have a Heathkit remote
antenna switch that is out in my 'doghouse' at the base of the tower.
Even though it is protected from the elements, I already had 1 relay
failure relay in it. It was used for switching between 4 different
dipoles, and rarely had to handle QRO. 100 watts or less 99% of the time.
If I can figure out what the trouble is, I may just use that box to switch
the different loops. The big question is what to do to prevent this from
happening again.
Thanks for reply.
Pat, KE1C
jbmitch
>>. SGC makes a
>>good tuner but other than that they are a bullshit outfit.
They also make a very fine 12 v 550 w mobile amplifier, the SG-500, which
I have been using for several weeks now. The quality of this amp puts
the MFJ/Amer. to shame...
- John
cmo...@sedona.intel.com
Bill Harwood <har...@sirius.chinalake.navy.mil> wrote:
>OK both of you, lets play nice.
Sorry, ran out of prozac. :-)
>The QMS system is rugged but just so so as an antenna. I use the
>SGC-230 in combination with the 303 antenna on rough terrain and 4wd but
>the SPIDER is on there the rest of the time.
Bill, I haven't ever seen the 303 but from the description I gather it
is a whip within a coil so it has two resonant points. Question: what
does the whip do to the Q of the coil? Do you know anything about the
bandwidth? If it's broadband, it's lossy? If it's not lossy, it's not
broadband? For non-resonant antennas, I follow the same rule for fixed
or mobile. No less than 3/8 wavelength for a dipole - no less than
3/16 wavelength for a monopole (whip). That's why I run a 13 ft whip
with the SGC-230 to cover 10m-20m mobile. The 14 ft. S10 pickup
counterpoise helps a lot.
Come to think of it, a 13 ft whip and a 14 ft counterpoise might cure
the portable backpack antenna problem that Joanna mentioned.
I've never tried my setup on 75m and on 40m it is one 'S' unit (6dB?)
down from a bugcatcher. That's better than I was expecting.
73, Cecil, KG7BK, OOTC
(100% my own fuzzy logic, not speaking for my employer)
cmo...@sedona.intel.com
In article <p5MAR9L...@delphi.com>, <arm...@delphi.com> wrote:
>Cecil: SGC makes the following claim (quote) " You can get more than 20 dB
>of gain by simply using an SGC compared with any other 1.8 to 30 MHz system."
> The most interesting point here are : 1.8-, which includes 75M and the with
>ANY other system. ANY other! They also say "will typically yield 20 dB of
>gain over a conventional 1.8 to 30 MHz mobile installation."
> These claims are either: (1.) verifiable, (2.) absurd, (3.) comical,
>(4.) disgusting, (5.) buffoonish. Please select your choice.
How about (6) misquoted? You could have done a lot better job on that
quote, e.g.:
"... you can get more than 20 dB of gain by simply using a QMS compared
with any other 1.8 to 30 MHz system."
That would at least have made people wonder what words you left out.
Here's the entire correct quote:
"So let us show you how you can get more than 20 dB of gain by simply
using a QMS compared with any other 1.8 to 30 MHz system" (possessing
the following problems). Problems 1-6 enumerated.
Yup, the last four words were added by me because it is pretty clear
to me that they were implied by the six problem areas that were then
discussed. I listed them a month ago and won't waste more bandwidth.
The key is that they said, "So let us show you...". Obviously, if one
doesn't suffer from the six problem areas that they enumerated, then
one will not realize the "20 dB of gain". Just as obviously, if one
doesn't suffer from any of the six enumerated problems, there will be
no gain at all. One can always read the six items and say, "Hey, they
didn't show me because I don't have the problems they listed".
They also say it "will typically yield 20 dB of gain over a conventional
1.8 to 30 MHz HF mobile antenna installation." Then they define
"conventional" as a "9 foot whip" under item 5. There probably *is*
some point in the HF spectrum where the SG-303 is 20 dB better than
a 9 foot whip, especially sans tuner.
So things are not nearly as bad as you (or Mr. Sturba) made them sound
and that is typical of Mr. Sturba. I would say that he stretched the
truth in the opposite direction more than SGC stretched the truth in
their favor.
SGC is certainly not without fault. Could be some sleazy marketing
type edited out the four implied words because it sounded negative.
He might also have edited out the "9 foot" just before "conventional"
in the first paragraph. The ad definitely could be misleading. Your
"quote" (in quotes since it wasn't a correct quote) was misleading.
So where do we stand? SGC didn't say what you said they said and
what they did say is potentially misleading for some people. But
misleading statements shouldn't be misquoted to make them even
more misleading.
My concern is that some companies may have suffered loss of revenue
because of Mr. Sturba's incorrect quotations. Ever considered editing
his column for accuracy?
Bill Harwood
Here is a data point for you. I was temporarily using my SCG-303
antenna with the SGC-230 (this is my 4wd configuration) not on the QMS
system. I was listening to an AM station on 1070 KHz. I tuned the
system up to 1500 KHz. The signal strength was less than S-1 on my
Yaesu 747. I just got my SPIDER 7 band (80 to 10 without 30) top load
repaired and put it on the truck (my highway configuration) and retuned
the SGC-230 to 1500 KHz and listend to 1070 KHz. Bingo S2 to S3. Both
antennas are on QD-2 couplers so e the change very quickly.
To be fair. I have also performed the SGC-303 to CB whip (106 inch
steel) comparison. That is a toss up on 15, 12 and 10. Buy the time
you are at 40 meters the differance is 2 to 4 S units in favor of the
SGC-303 and the whip is even worse at 80 meters. All with the SGC-230.
The SGC-230 is a wonderful toy, I love it and it is real rugged. It
will not replace lots of wire or real good antenna design.
The QMS system is rugged but just so so as an antenna. I use the
SGC-230 in combination with the 303 antenna on rough terrain and 4wd but
the SPIDER is on there the rest of the time. Yes I always drive the
SPIDER through the SGC-230
Have a great day and smile a little
Remember its a hobby,
Bill Harwood
AB6DY
arm...@delphi.com
To your 5/4 dipole. You claim 9dbi. That is 7dBd. Your antenna is about
83.6 feet long. A half-wave dipole would be about 33.4 ft. Your antenna is
2.5 half-wave dipoles. Assuming it takes a doubling of antenna size to pick up
3dBd, now we are at 2 HW. Since it would take another TWO half-waves to pick up
another 3dBd, the quarter-wave remaining adds a miniscule amount.
As to where the other 4dBd you have claimed are hiding in all this is a good
question.
"square" antenna (which you mocked) beat your dipole? Yes. Since
you chose to go to an "extended" dipole, I will go to the square antenna
as outlined by Bill Orr on page 99 of his book "Quad Antennas".It is the
"expanded" Quad, which is one half-wave on a side. It is a total of 2 WL
to your 1-1/4.Touche'
Next, the SGC: Their statements are: will typically yield 20dB of gain
over a conventional 1.8 to 30 MHz HF HF mobile installation." Contrary to
your interpretation, a "conventional, etc" would not have all of the outlined
maladies they later mention.
Next, here is the true crux of the matter: "you can get more than 20dB of
gain by simply using a QMS compared with any other 1.8 to 30 MHz system.
"let us show you how" They have committed themselves to saying ANY OTHER.
As to their qualifiers: If you add them all up (as they state) you can get
as high as nearly 40dB difference. That is 10x10x10x10. Or the difference
between 100 Watts and .01 (1/100) of a watt.
Just how totally bad would an antenna have to be to get beat like that
by anything. Hardly a "conventional" antenna.....or "ANY OTHER" 1.8-30 MHz
system.
Your remarks are, of course, invited and will be given studious thought.
PS. Only another OF would remember the back porch ice cream maker, round and
round the crank went.
arm...@delphi.com
>What you don't know is the string had accidentally been soaked with
>salt water draining off an ice cream maker the night before.
arm...@delphi.com
>"conventional" as a "9 foot whip" under item 5. There probably *is*
>some point in the HF spectrum where the SG-303 is 20 dB better than
>a 9 foot whip, especially sans tuner.
this and in the flurry of data whizzing around faxwise was something I
had never stopped to think about. That 20 dB represents a 100 times power
difference. What absolute piece of junk would an an antenna, any antenna,
have to be to radiate 1/100 of the power of that of some aother antenna.
A tin cup an a wire wouldn't be down 20 dB????????
arm...@delphi.com
Bill Harwood
looking at HF antennas for small craft in the early 1960's. Their
research showed that the higher you load an antenna the better its
efficiency. Thus I use a top loaded SPIDER and an SGC-230 to broaden
the frequency coverage. The SGC-303 antenna on the QMS system is sort
of two continuous loaded antenna sections which are supposedly,
according to the literature, resonate at about 10 MHz and 15 MHz
approximatly. I have never been satisified with the transmit or recieve
performance of the SGC-230 and SGC-303 combination.
Have a Great One
Bill Harwood
AB6DY
Bill Harwood
screw driver antennas hit the market. The only thing for the no hands
test that would lay a glove on them was an old home brew DK-3 (from the
instructions) or one of the old hydraulic models from the 50s-60s.
I like SGC but the claim for the QMS is about like all of the adds that
Kurt N Sterba pings on every month.
Bill Harwood
AB6DY
Bill Harwood
even if he is far from perfect.
Lets say he is 3 db better than a shopping cart and matbe better than a
ladder. How is that?
Bill Harwood
AB6DY
cmo...@sedona.intel.com
Gerald Schmitt <g...@aerie.lanl.gov> wrote:
>I don't think SGC can tolerate too much technical scrutiny.
I called SGC and asked them how they justify their claims. Their
advertising is based on the following shootout which they said
they would be glad to see.
Set up any mobile antenna system under 10 ft long before the
testing begins. A "no hands" rule applies after the test begins.
Run tests on every HF band keeping the "no hands" rule in effect
for the duration of the tests. Average the tests for each
configuration. They think the QMS system will win the shootout
against a bugcatcher with a fixed tap.
When they say, "Outperforms *any* other antenna system under 10
feet covering the full 1.8 to 30 MHz HF range", they are assuming
the "no hands" rule. Just change bands while in motion and push
the mike button. It appears they have not heard about the auto-
tune screwdriver antennas which should win the above shootout.
73, Cecil, KG7BK, OOTC
(100% all my own fuzzy logic, not speaking for my employer)
Bill Harwood
auto tuner in the AMP. Will it only get the right band or will it tune
almost any load like the SGC-230?
I have been considering one of these amplifiers but want to stick with
an auto tuner.
Thanks,
Bill HArwood
AB6DY
Bill Harwood
with the QMS. SGC-303 is the seperate part number
Have a great weekend...
Bill Harwood
AB6DY
cmo...@sedona.intel.com
> To your 5/4 dipole. You claim 9dbi. That is 7dBd.
Actually 3dBd because I modeled it over real ground, not free space.
A half-wave dipole over real ground is about 6~7 dBi according to
ELNEC.
> ..."square" antenna (which you mocked) beat your dipole? Yes. Since
>you chose to go to an "extended" dipole, I will go to the square antenna
>as outlined by Bill Orr on page 99 of his book "Quad Antennas".It is the
>"expanded" Quad, which is one half-wave on a side. It is a total of 2 WL
>to your 1-1/4.Touche'
Ouche' -- remember it has to perform equally well on 20m and 17m with
broadside lobes on 20m and cloverleaf lobes on 17m and mount on my
two 30 ft supports. If it can't do all that then it's not "better" than
my dipole. Point is, if squares were "always better" than dipoles, then
no sane person would use a dipole.
> Next, here is the true crux of the matter: "you can get more than 20dB of
>gain by simply using a QMS compared with any other 1.8 to 30 MHz system.
> Their statement is ANY OTHER. ANY OTHER! It doesn't matter if they say,
>"let us show you how" They have committed themselves to saying ANY OTHER.
They forgot to let you in on the rules. The test must be performed from a
continuously moving vehicle using each HF band in turn. Once you've chosen
your antenna configuration, you must stick with that same configuration for
all the HF bands. You are not allowed to stop the vehicle or climb the
mast. Makes some sense if the antenna system is mounted at the top of
a mast during a storm.
>PS. Only another OF would remember the back porch ice cream maker, round and
>round the crank went.
OF is right - my eyesight is getting so bad I can't find the crank anymore.
Dave Wright
>My concern is that some companies may have suffered loss of revenue
>because of Mr. Sturba's incorrect quotations. Ever considered editing
>his column for accuracy?
If it was edited for accuracy, I think it would end up being to short.
--
David Wright - N8IT
da...@freeway.net
cmo...@sedona.intel.com
Bill Harwood <har...@sirius.chinalake.navy.mil> wrote:
>Kurt is at least more accurate than most of the antenna adds you see
>even if he is far from perfect.
Hi Bill, I never never meant to imply that his column is nearly as
inaccurate as the antenna adds. It's just when one sets oneself up as
near-perfect, one might expect the same judgement techniques one is using
to be used to judge one's own work. You know, let he who is without sin
cast the first stone... people in glass houses... etc.
>Lets say he is 3 db better than a shopping cart and matbe better than a
>ladder. How is that?
Of course, he is doing more good than not. Just wish that his colunm
was not 10% as outrageous as the adds he blasts. Of the 100% distance
between the adds and Kurt's position, I am about 10% toward the center
from Kurt. Hope that defines my position.
Rob Silva
>In article <BNKDiEM...@delphi.com>, <arm...@delphi.com> wrote:
>><cmo...@sedona.intel.com> writes:
>>Some point in the spectrum. I thought we had to stay in the amateur bands.
>Hi Armond, it occurred to me last night after my posting that you and
>I could be suffering from language problems. Unfortunately, I learned
>my English in Texas (some say they don't speak English in Texas :-)
>I was speaking in the context of the HF amateur bands. Here's how their
>claim could be true. Compare the QMS antenna system with a "conventional
>9 ft whip" on 30m. Use my IC-725. I have no doubt that the QMS system
>will radiate 20 dB more RF than the barefoot IC-725 because of foldback.
>Admittedly, I am playing devil's advocate. I am not defending their claims.
>I am demonstrating how they may be rationalizing their claims.
>My native Japanese friends will never understand the difference between
>"can" and "will". Compare the following two statements:
>I can die tomorrow. Obviously true
>I will die tomorrow. Probably false, hopefully I am mistaken.
>SGS didn't say the QMS system "will" make a 20 dB difference. They
>said it "can" make a 20 dB difference, given a certain set of
>circumstances, which they enumerated. We all know that they exaggerated
>the effects of the items they listed and it is not likely that all
>the items would ever exist in unison. They may have meant to convey
>the impression that the QMS system is 20 dB better, but they didn't
>say it "will" improve things by 20 dB.
I for one don't think they were being deliberately deceitful at all. Go back
and look at the list of losses they enumerated. Clearly there are some
exaggerations and it would be unlikely to get all of them in unison. Bear in
mind, however, that all of the losses they list could be encountered in a
conventional SG-230 + Whip installation. Perhaps they're just bagging their own
product ;-)
--
-----------------------------+------------------------------------------------
Rob Silva | The sooner you fall behind, the more
| time you have to catch up
rsi...@adelaide.DIALix.oz.au |
cmo...@sedona.intel.com
Rob Silva <rsi...@adelaide.DIALix.oz.au> wrote:
>I for one don't think they were being deliberately deceitful at all. Go back
>and look at the list of losses they enumerated. Clearly there are some
>exaggerations and it would be unlikely to get all of them in unison. Bear in
>mind, however, that all of the losses they list could be encountered in a
>conventional SG-230 + Whip installation. Perhaps they're just bagging their own
>product ;-)
Hi Rob, it took me a day after talking to them to experience their mind
set. (where they are coming from, as my daughter would say). Their world
has an antenna system at the top of a 20 foot mast. One installs it and
uses it, as is, for all-band HF operation. An auto-tuned screwdriver may
win under those conditions, but I don't know of anything else that would
be better than the SGC system *for those circumstances*. Looks to me the
mistake that SGC made was assuming that land vehicles have the 20 foot
mast problem to contend with. Still, a shootout from a moving vehicle
would make the SGC system look good against anything that is not auto-
tuned over the whole amateur HF spectrum.
Jim, W5GYJ, would win such a shootout. He has a bugcatcher on his pickup
and could have me in the back changing taps. "Don't key up yet and watch
that curve." :-)
Bart Rowlett
>In article <pZFCBpE...@delphi.com>, <arm...@delphi.com> wrote:
>
>>Also, I think they are looking for local area
>>work..road conditions, weather, restaurants, hotel info and chatting with
>>friends, etc.
>
>In AZ and CA 2m works best for this type stuff. One will radiate more
>RF from a 40w 2m mobile that from a 100w 75m mobile. If we could get
>all the mobiles off 75m and onto the more efficient 2m, the universe
>would not run down quite as fast. :-)
Probabaly more than a 1KW mobile but it's signal to noise ratio at
the receiver that counts. Don't forget the receive antenna collects energy
in proportion to the wavelength squared which make up for the ionospheric
reflection losses. 75m mobile works great in canyons and is often
superior in performance to 2m and sometimes not.....
>
>>Do you believe that on 15, the SGC claims of 20 dB gain over
>>ANY other system would be valid?
>
>What I believe is that SGC never made that claim. Fortunately,
>Mother Nature doesn't care what I believe, what you believe that SGC
>has claimed, or what SGC has actually claimed. My 13 ft whip fed with
>the SGC-230 outperformed an 8 ft bugcatcher on 12m and it doesn't matter
>what your alleged omniscient writer for Worldradio thinks. (Remember,
>you said he never makes mistakes).
There shouldn't be much more than a dB or so of difference between them
unless the bugcatcher coil happens to be self resonant up there.
>
bart wb6hqk
cmo...@sedona.intel.com
returning my two bucks.
In that issue, "Aerials" used more than half the column slamming a
company selling an auto-tuner and vertical antenna for $900, not for
the price but for the claim, "eliminates power-draining antenna wire-
runs between the (SGC-303) antenna and (SGC-230) tuner."
Mr. Sterba then used (1) a 50 ohm antenna??? and (2) an SWR of 4:1???
to "prove" that this antenna company was wrong. He strongly implies
that the loss in 10 ft of RG-213 is neglible. He then offers the
challenge, "I'll be short of breath the whole time waiting for the
rebuttal..." The rebuttal didn't come from Bellevue, It came from
me.
I pointed out that there was no (switchable) loading coil in the
SGC system and instead of 4:1, the SWR might be 400:1. I calculated
the loss in 10 ft of RG-213 at *7 dB* using a 9 ft. whip on 20m
as an example where the loss in 10 ft of RG-213 is *not* neglible.
I don't have an SGC-303 antenna but I'm willing to bet that the
loss in 10 ft of RG-213 feeding an SGC-303 antenna without an SGC-230
tuner, is indeed "power draining" in contradiction to what Mr. Sterba
implied in his column. He did not talk about the expected high SWR
with the SGC-303 antenna, so why did he slam their true statement?
Instead of a "power-draining" sky high SWR between the tuner and the
antenna, the SWR between the auto-tuner and the transceiver is near
perfect.
Please don't mention "blast holes through major mountain ranges and
probably some laws of physics." I concede they can not blast holes
through the laws of physics.
arm...@delphi.com
>In an earlier article, Kurt said that a square antenna is always better
>than a dipole. I challenged him to come up with a square that will
>outperform my 88ft dipole on 20m *and* 17m (2 lobes@9dbi and 4 lobes@
>8dbi respectively). I haven't heard anything from him.
You have said many times that WR or later KNS "stretches the truth and you give
your answer to his statement as your version of the proof or the truth.
NOT a dipole to start with. Here: "It is a
collinear dipole, although it can't rightfully be called a dipole because
each half of its length is greatervthan 1/2 WL (each half is actually 0.64WL).
This means that is has a reversal of current flow in each antenna half, and
therefore has more than two "poles". Thus, your antenna is not a dipole at all.
cmo...@sedona.intel.com
> NOT a dipole to start with. Here: "It is a
>collinear dipole, although it can't rightfully be called a dipole because
>each half of its length is greater than 1/2 WL (each half is actually 0.64WL).
>This means that is has a reversal of current flow in each antenna half, and
>therefore has more than two "poles". Thus, your antenna is not a dipole at
>all.
Hi Armond, a "dipole" is a generic term defined as "a radio antenna
consisting of two horizontal rods in line with each other with their ends
slightly separated". Saying a collinear dipole is not a dipole is like
saying a red car is not a car. "Collinear", "folded", "half-wave", "short",
and "trap" are all adjectives that can be used with the noun "dipole"
which means two *physical* poles - nothing said about length or frequency.
If Kurt was talking about a half-wave dipole, he should have said so.
And even if he was, a 40m half-wave dipole mounted on my 30 ft masts
will outperform a 40m full-wave square mounted on those same masts
according to ELNEC.
arm...@delphi.com
>Hi Armond, a "dipole" is a generic term defined as "a radio antenna
>consisting of two horizontal rods in line with each other with their ends
from a serious book. If people "generic" term use is wrong, that does not
make it correct. You can not find a serious book where dipole is used for
anything but the everyday normal 1/2 wave antenna. Your antenna is a multi-
pled antenna which can not be a "di" pole. No way. Also, how can you justify
those gain figures for nothing more than 2 5/8 wave antennas. One is a
smidge over a dipole and the other is 3dB over that?????Where all those
other numbers coming from???????
cmo...@sedona.intel.com
>>a "dipole" is a generic term defined (quoting the dictionary) as
>>"a radio antenna consisting of two horizontal rods in line with each
>>other with their ends slightly separated".
>You can not find a serious book where dipole is used for
>anything but the everyday normal 1/2 wave antenna.
We are probably at the crux of the problem. If you don't believe Webster's
Ninth New Collegiate Dictionary is a "serious" book, we do not share a
common language. Do you believe "The ARRL Antenna Book" is not a "serious"
book? Take a look at "dipole" in the index. There are 24 sub-topics under
"dipole". One of those sub-topics is "Half wavelength". Others are "Cage",
"Fan", "Folded", "Short", and "Trap", all adjectives describing different
types of "dipoles". A "dipole" is an antenna with two physical poles.
(Butchering the English language is a pet peeve of mine.)
>Also, how can you justify
>those gain figures for nothing more than 2 5/8 wave antennas. One is a
>smidge over a dipole and the other is 3dB over that?????Where all those
>other numbers coming from???????
Directly from ELNEC modeled at 30 ft over *real ground* so I guess the
question needs to be directed to W7EL. A half-wave dipole over *real
ground* has about 6dbi gain. a 10/8 dipole should be about 3db better.
ELNEC says that a 20m 10/8 dipole has an 8dbi clover-leaf pattern on 17m
over *real ground*. Do you disagree with ELNEC? If so, that's about the
only new thing in this thread.
David Stockton
: You can not find a serious book where dipole is used for
: anything but the everyday normal 1/2 wave antenna.
I prefer funny books.
David, GM4ZNX
arm...@delphi.com
>"dipole". One of those sub-topics is "Half wavelength". Others are "Cage",
>"Fan", "Folded", "Short", and "Trap", all adjectives describing different
have quoted is spoken of as being more than 1/2 wave long. Again, Your
antenna has MORE THAN two (di) elements. Your antenna (as was explained),
(read slowly please): "It is a collinear, it can't be rightfully be called
a dipole becuase each of its length is greater than 1/2 WL (each half is
actually 0.64WL) This means it has a reversal of current flow in each half, and
therefor HAS MORE THAN TWO POLES.Hence, the EDZ (extended double Zepp)
rightfully belongs in the realm
of the long wire". Now, it is your right and privelige to argue all you want
that it is a dipole even though it is not.
As to all this gain. At the exact same height, what gain would your antenna
have over a dipole at the same height. Forget all this isotropic and reflected
ground gain...the question is , compared to a dipoleat the same height what
would
the advantage of the edz be??????
cmo...@sedona.intel.com
>I will speak slowly.You have evaded the issue, 1st none of the dipoles you
>have quoted is spoken of as being more than 1/2 wave long. Again, Your
>antenna has MORE THAN two (di) elements.
Come on over to my house and see with your own eyes, my antenna has
two and only two elements. It don't take a rocket scientist to count
to two.
>Your antenna (as was explained),
>(read slowly please): "It is a collinear, it can't be rightfully be called
>a dipole becuase each of its length is greater than 1/2 WL (each half is
>actually 0.64WL) This means it has a reversal of current flow in each half, and
>therefor HAS MORE THAN TWO POLES.Hence, the EDZ (extended double Zepp)
>rightfully belongs in the realm
>of the long wire". Now, it is your right and privelige to argue all you want
>that it is a dipole even though it is not.
You and I have a difference of opinion over the definition of a
word. I look in the dictionary and find your definition is incorrect.
The dictionary of the English language says my antenna is a dipole.
I will not argue with you any longer over definitions. I will simply
refer you to the "OFF-CENTER-FED (multi-band) DIPOLE" section of the
ARRL Antenna Book. Poles are physical, just like fishin' poles. You can
look at them and count how many you have. I guarantee you that when the
word "dipole" was coined, they were referring to physical poles. The
dictionary reflects that fact.
You are saying that an off-center fed multi-band dipole is only a dipole
on its fundamental frequency? So when it's used to receive WWV, it morphs
into something other than a dipole? "Hey Maw, go watch what happens to
my antenna when I change receive frequencies! No, it won't stay the same.
Armond says it grows some more poles." I consider your argument ridiculous
so this is my last posting on the definition of dipole. We are wasting
bandwidth if you won't open a dictionary.
>As to all this gain. At the exact same height, what gain would your antenna
>have over a dipole at the same height. Forget all this isotropic and reflected
>ground gain...the question is , compared to a dipole at the same height what
>would the advantage of the edz be??????
I assume you mean a "half-wave dipole"? Theory is 3 db. Elnec says 3 db.
It's the same as the theoretical gain of a 5/8 wavelength monopole
over a 1/4 wavelength monopole. My 88 ft multi-band dipole was very
carefully designed to meet my 30 ft height restrictions with 3dbd gain
over a half-wave dipole on 20m *and* 17m. No square will beat it on all
(I doubt any) bands given the boundary conditions. Therefore, a square
will not "always" beat a dipole! It's a dead horse. It ain't gonna gittiup.
ps. I learned these discussion techniques from Kurt N. Sterba, the
greatest nit-picker of them all.
Dick Hughes
><cmo...@sedona.intel.com> writes:
>
>>"dipole". One of those sub-topics is "Half wavelength". Others are "Cage",
>>"Fan", "Folded", "Short", and "Trap", all adjectives describing different
>
>I will speak slowly.You have evaded the issue, 1st none of the dipoles you
>have quoted is spoken of as being more than 1/2 wave long. Again, Your
>antenna has MORE THAN two (di) elements. Your antenna (as was explained),
>(read slowly please): "It is a collinear, it can't be rightfully be called
>a dipole becuase each of its length is greater than 1/2 WL (each half is
>actually 0.64WL) This means it has a reversal of current flow in each half, and
>therefor HAS MORE THAN TWO POLES.Hence, the EDZ (extended double Zepp)
>rightfully belongs in the realm
>of the long wire". Now, it is your right and privelige to argue all you want
>that it is a dipole even though it is not.
>As to all this gain. At the exact same height, what gain would your antenna
>have over a dipole at the same height. Forget all this isotropic and reflected
>ground gain...the question is , compared to a dipoleat the same height what
>would
>the advantage of the edz be??????
Hey guys, could we talk about our experiences with the SGC tuner? I
would really like to hear about it.
Dick Hughes - W7LVA
cmo...@sedona.intel.com
>Hey guys, could we talk about our experiences with the SGC tuner? I
>would really like to hear about it.
Gladly, The tuner is the SG-230 and the SGC antenna is the SG-303. I
don't know much about the antenna except it doesn't work well on 75m.
The SG-230 antenna tuner is a pi network tuner, switched cap banks to
ground and switched series inductors. The switching is done by a
microcontroller which initializes all the caps out of the circuit, i.e.
open circuit, and all the coils out of the circuit, i.e. short circuit.
The beauty of that is if the antenna has a low SWR at the present
frequency of operation, the SG-230 puts nothing but a near-short
between the input and the output. It's a less lossy design than the
average MFJ T network where one must have two capacitors and an
inductance in the circuit at all times (or else switch to direct coax
if that function exists).
For 75m mobile, one usually needs a coil at the base of a bugcatcher
in addition to the center loading coil and taps must be changed to
maintain a low SWR over the entire band. I use a homemade bugcatcher
on 75m with no coil at the base because the SGC-230 performs the
function of the base coil. In addition, I can cover the entire 80m-
75m band without switching taps. The same is true for 40m which is
a single tap on my bugcatcher. The SGC-230 allows me to tune the
entire 40m band without changing taps.
My favorite setup is a 17m resonant whip (13 ft, no coils) which acts
as a non-resonant monopole on all other 20m-10m bands. It outperforms
my bugcatcher on 17m-10m and one must have an eagle eye to detect
any difference on 20m. IMO this setup can't be beat for automatic
multi-band mobile operation 20m-10m. Much to my surprise, the SG-230
and the 13 ft whip is only one 'S' unit down from my bugcatcher on
40m. That one 'S' unit usually doesn't make an appreciable difference.
I never have to worry about transmission line losses.
The SG-230 has no coax connector on the output, just a high voltage
terminal which must be connected directly to the antenna with a
short as possible piece of large wire, like the center conductor
of RG-8. Where the SG-230 really makes sense is maritime mobile.
arm...@delphi.com
is there in the 15ft of coax from rig to antenna if the tuner wasn't at
the antenna?
cmo...@sedona.intel.com
>>I never have to worry about transmission line losses.
(said in the context of non-resonant mobile whips which apparently
went right over Armond's head)
>Assuming using an antenna resonant for the band in use......How much loss
>is there in the 15ft of coax from rig to antenna if the tuner wasn't at
>the antenna?
Armond, I think you have picked up some bad habits from Kurt N.
Sterba, like not listening.
As I have previously posted, I do not use a resonant antenna. I use a
13 ft non-resonant whip with an SWR of 30:1 on 12m. Assuming 15 ft of
RG-58, the coax loss would be 6.4 db. The SGC-230 allows me to radiate
4 times the power I would if I had the tuner at the transmitter.
I assume your question was rhetorical since everybody already knows
the answer. I am not recommending the SGC-230 for a 50 ohm antenna.
I am recommending it for a 400+j600 ohm antenna, like mine is on 12m.
However, I know someone who uses the SGC-230 with a bugcatcher so he
doesn't have to stop to change taps within a band.
arm...@delphi.com
Mark G. Salyzyn
>cmo...@sedona.intel.com writes:
>> [...] IMO, it is illogical to deliberately choose a band for mobile
>>operation where the ground-loss resistance is ten times the radiation
>>resistance. IMO, the higher bands are better candidates for mobile
>>operation. For me, 75m mobile is a last resort [...]
>The reason 75m is an interesting mobile band is that it's a tough one
>to do right.
Here here! Although I use an 80m Hamstick on the roof of my rolling playpen,
and an SGC tuner to make it cover the entire band, I still know I can do a
heck of a lot better *somehow*. Just knowing this is far more exciting than
putting a dinky 5/8 wave 2m magmount up on the 128 square feet of ground plane
my Buick presents to me ...
It was fun, though, putting up an 22 element 70cm parabeam on the roof of
the rolling playpen though!
2m is defined as: Plug and play for the appliance operators ...
>One pleasant part of the ham experience is to deliberately accept a handicap,
>such as this problem of radiation efficiency, and to overcome or work around
>it. I've worked 75m mobiles (on phone) over ~4000 km paths and in doing so I
>felt both a sense of accomplishment and of admiration for the other fellow's
>skill in building such a excellent mobile rig; my hearing him was no special
>trick (500' beverage) but him hearing me was most remarkable.
This glorification aside, Ross, might we wonder aloud that the 75m work you
have been doing had more to do with the license restrictions you had
(80 and 160m phone only) and the acres and acres of prime hilltop space you
enjoy! ;->
Ciao -- Mark
cmo...@sedona.intel.com
Hey Armond, that's a big step. We probably agree more than you know.
Somewhere between Icom's recommended maximum SWR of 2:1 and the point
where a transmitter starts to fold back, is a point where an antenna
tuner will help and, at that point, it doesn't matter if it's located
at the transmitter or the antenna. Then, somewhere at a higher SWR,
depending on frequency and the particular coax chosen, a base-mounted
antenna tuner becomes superior to an antenna tuner located at the
transmitter.
SGC publishes a lot of marketing hype but besides the SGC-303 antenna,
they sell some pretty good stuff. I am happy as a pig-in-you-know-what
with the SGC-230 auto-tuner. I run a non-resonant dipole fed with
ladder-line at home with a tuner at the transmitter. I can't feed
my non-resonant mobile monopole with ladder-line so I do the next
best thing - locate the tuner at the antenna. Not for everyone but
it works for me.
I have a metaphysical question that I don't know the answer to:
Do you think there's an SWR on the 2 inches of wire between the
SGC-230 and my mobile antenna? Of course, one can measure it, but
then it wouldn't be 2 inches of wire.
arm...@delphi.com
and just plain old BS? On your two inches of wire, if each day you cut it
in half, how long will it take for there to be no more wire? regards.
Bart Rowlett
>
>I have a metaphysical question that I don't know the answer to:
>Do you think there's an SWR on the 2 inches of wire between the
>SGC-230 and my mobile antenna?
Yep. The characteristic impedance of the fairlead between the SGC-230
and the antenna base is probably a few hundred ohms. Figure about
25 nH per inch inductance, the capacitance is as presumably as low
as possible but probably on the order of 0.1 pF per inch. The
resulting characteristic impedance is sqrt(L/C), approximately 500
ohms or more.
>Of course, one can measure it, but
>then it wouldn't be 2 inches of wire.
True...
bart wb6hqk
cmo...@sedona.intel.com
Bart Rowlett <ba...@wb6hqk.ampr.org> wrote:
>Yep. The characteristic impedance of the fairlead between the SGC-230
>and the antenna base is probably a few hundred ohms. Figure about
>25 nH per inch inductance, the capacitance is as presumably as low
>as possible but probably on the order of 0.1 pF per inch. The
>resulting characteristic impedance is sqrt(L/C), approximately 500
>ohms or more.
Hi Bart, I think you are saying that there will be reflections and I'm
sure there will be. The question is, will there be standing waves?
Someone has said, "How can there be standing waves when there is no
place to stand?" IMO if the reflected energy is re-reflected in a
manner that reinforces the same phase of the same cycle, there are no
standing waves. IMO for a standing wave to exist, the reflected energy
must be re-reflected in a manner that reinforces a subsequent cycle.
Of course, this may be just another semantic difference.