Ian Jackson wrote:
Evenin' Reg.
Not disagreeing with you at all. Just nit-picking about your less than
immaculate grammar!

My only problem with baluns is not understanding the obsession with the
4:1 or 9:1 transformation ratio.

Reg was relying to a different Ian :-)

--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

In message , "Ian White, G3SEK"
writes
Ian Jackson wrote:
Evenin' Reg.
Not disagreeing with you at all. Just nit-picking about your less than
immaculate grammar!

My only problem with baluns is not understanding the obsession with
the 4:1 or 9:1 transformation ratio.

Reg was relying to a different Ian :-)


I suspected as much when I then spotted the thread to which I was
replying in another newsgroup. Put it down to crossmodulation, or maybe
old age.
Ian.
--

Buck wrote:
I have been looking at OCF dipoles and there are some that don't
appear to need a tuner when using a 6:1 balun.

I ran an OCF in college with a 6:1 air core balun from
Heathkit. It worked well but my transmitter had a
built in adjustable pi-net tuner. What are the dimensions
of the above OCF that you have described? Most OCF's that
I have modeled work just as well with a 4:1 balun as they
do with a 6:1 balun.

Jerry Sevick, W2FMI, describes a 6.25:1 balun in "Building
and Using Baluns and Ununs". It is a 1:1.56 UNUN followed
by a 1:4 BALUN.
--
73, Cecil http://www.qsl.net/w5dxp


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It is highly instructive to NOT think of a balun as an impedance
transformation device, but rather as a device which has the ability to steer
r-f currents. Thus viewed, a large amount of confusion melts away.


--
73, George W5YR
Fairview, TX

http://www.w5yr.com


"Reg Edwards" wrote in message
...
Dear Ian,

It's early in the morning. I havn't had time and I don't want to take
much
time thinking about your rather slightly surprising comments.


You have completely misunderstood, gone off at a tangent, about my motives
in my very few writings on the subject of baluns.


I have never made recommendations about old-wives tales, whatever you
think
they are, except, just in effect, to ignore them.


You, apparently, have now (quite mistakenly I venture to add) included
yourself amongst them.


Have you any shares in balun manufacturers? After all baluns are the only
thing left for old-wives and salesmen to haggle about. Don't bother
answering.


In conclusion, unless people can specify, in numerical terms, what is
their
problem, then there's no hope of sensibly aquiring a balun of any sort.
And
I have never yet met anybody who has so specified.

I feel guilty at prolonging such a trivial matter. But it's such an early
hour of the day. Havn't had breakfast yet!

A very good morning to you Ian.
---
Reg, G4FGQ

On Sun, 30 Jan 2005 22:24:00 -0600, Cecil Moore
wrote:

Buck wrote:
I have been looking at OCF dipoles and there are some that don't
appear to need a tuner when using a 6:1 balun.

I ran an OCF in college with a 6:1 air core balun from
Heathkit. It worked well but my transmitter had a
built in adjustable pi-net tuner. What are the dimensions
of the above OCF that you have described? Most OCF's that
I have modeled work just as well with a 4:1 balun as they
do with a 6:1 balun.

Jerry Sevick, W2FMI, describes a 6.25:1 balun in "Building
and Using Baluns and Ununs". It is a 1:1.56 UNUN followed
by a 1:4 BALUN.


This is the antenna I want to copy before I start experimenting:
http://hamcall.net/6bandmegpole.html

I don't have a lot of information about baluns. What I have is mostly
related to Toroid baluns. I like the air coil idea in spite of the
size requirements. If additional turns or less turns change the balun
ratio, I would be interested to know as I can experiment and try
variations.

Thanks.


--
73 for now
Buck
N4PGW

Buck wrote:
This is the antenna I want to copy before I start experimenting:
http://hamcall.net/6bandmegpole.html

Hi Buck, they don't give exact building information as far
as I can tell. Here's what they say: Inverted V with the
center at 32 ft and ends at 8 ft. Approximately 135 ft
long fed with 100 ft of RG-213.

Why 32 ft with the ends at 8 ft? Because that is the
configuration that gives the advertised values of SWR.
Why 100 ft of RG-213? Because the losses in the coax
results in the advertised values of SWR. If you deviate
from their configuration including having different
ground conditions, you will, no doubt, need an antenna
tuner for some bands. They have probably fine tuned their
configuration so they can make their claims which you
probably will not be able to duplicate. I don't want to
discourage your experimentation - just make a prediction
based on experience.

If you really want an efficient all-eight-HF-band antenna
requiring no tuner, you can find one on my web page at
http://www.qsl.net/w5dxp/notuner.htm
If you don't want to go to the trouble of varying the
length of your feedline, you can at least learn what
you are up against in your quest.
--
73, Cecil http://www.qsl.net/w5dxp


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On Mon, 31 Jan 2005 08:42:30 -0600, Cecil Moore
wrote:

Buck wrote:
This is the antenna I want to copy before I start experimenting:
http://hamcall.net/6bandmegpole.html

Hi Buck, they don't give exact building information as far
as I can tell. Here's what they say: Inverted V with the
center at 32 ft and ends at 8 ft. Approximately 135 ft
long fed with 100 ft of RG-213.

Why 32 ft with the ends at 8 ft? Because that is the
configuration that gives the advertised values of SWR.
Why 100 ft of RG-213? Because the losses in the coax
results in the advertised values of SWR. If you deviate
from their configuration including having different
ground conditions, you will, no doubt, need an antenna
tuner for some bands. They have probably fine tuned their
configuration so they can make their claims which you
probably will not be able to duplicate. I don't want to
discourage your experimentation - just make a prediction
based on experience.

If you really want an efficient all-eight-HF-band antenna
requiring no tuner, you can find one on my web page at
http://www.qsl.net/w5dxp/notuner.htm
If you don't want to go to the trouble of varying the
length of your feedline, you can at least learn what
you are up against in your quest.


thanks, Cecil.

I have looked at that before.

( Not to argue with you, but I considered your feedline switches a
form of tuner, just not conventional .

That is definitely a great looking antenna. I am glad you pointed out
the precision needed on the OCF I was looking at. What I am working
towards is a great all-band antenna that can be easily ported and
setup and used without switching (kind of like the T2FD) and no
unique parts required.

I am glad to meet you (and know who you are.) To be honest, I have
spent a lot of time on your site. At one time, I could have answered
many questions about your antenna without looking at it. Your site is
the first place I saw the ferrite beads on the feedline for a choke
and I have investigated them in depth since then too.

One thing I didn't find about the antenna was the bandwidth of 40/80
meters or an SWR chart for each band. (I realize that you might not be
able to do that easily, I'm just stating an observation.)

Also, in addition to the antenna I mentioned to you (It was only one
of several OCF's I am looking at), it seems to be common for OCF
antennas to use 6:1 baluns. Some do use 4:1 and most, regardless of
the balun, require a tuner.

I have several ideas that I am kicking around so being able to easily
be able to build an inexpensive balun at different ratios will come in
very handy for my experiments.

Before the internet there were books. The best one could hope for was
to see a picture of the author on the cover, but now, after all these
years, I am still amazed when I find myself in conversation what use
to be ... the untouchables.

It was great to meet you. Thanks for replying.

Buck.


--
73 for now
Buck
N4PGW

reggie wrote:
"I would like to build baluns with non-conventional ratios,---"

"Conventional" may mean a coil balun such as was common for TV reception
not so long ago. These were essentially transformers with a two to one
turns ratio which provides an impedance ratio of the square, or four to
one. This is similar to a center-tapped coil. The TV balun gives a
75-ohm coax connection to a 300-ohm balanced twin-lead connection.

My 1987 efition of the ARRL Handbook shows how to use RF transformers to
step up / step down impedance in Chapter 16. Also, ON4UN shows how to
match high-impedance to coax on page 6-14 of the 2nd edition of
"Low-Band DXing", an ARRL published book.

Best regards, Richard Harrison, KB5WZI

Buck wrote:
( Not to argue with you, but I considered your feedline switches a
form of tuner, just not conventional .

More precisely, a form of tuned feeders.

One thing I didn't find about the antenna was the bandwidth of 40/80
meters or an SWR chart for each band. (I realize that you might not be
able to do that easily, I'm just stating an observation.)

The HF bandwidth of that antenna *plus* the tuned feeders is 27
MHz, all the way from 3 to 30 MHz with an SWR of less than 2:1
(for the ham bands). I haven't measured the SWR outside of the
ham bands. There's a graphic that shows the SWR=2:1 bandwidth
for 40m to be about 160 kHz for a fixed length of ladder-line.
--
73, Cecil http://www.qsl.net/w5dxp


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On Mon, 31 Jan 2005 12:24:20 -0600, Cecil Moore
wrote:

Buck wrote:
( Not to argue with you, but I considered your feedline switches a
form of tuner, just not conventional .

More precisely, a form of tuned feeders.

One thing I didn't find about the antenna was the bandwidth of 40/80
meters or an SWR chart for each band. (I realize that you might not be
able to do that easily, I'm just stating an observation.)

The HF bandwidth of that antenna *plus* the tuned feeders is 27
MHz, all the way from 3 to 30 MHz with an SWR of less than 2:1
(for the ham bands). I haven't measured the SWR outside of the
ham bands. There's a graphic that shows the SWR=2:1 bandwidth
for 40m to be about 160 kHz for a fixed length of ladder-line.


how much RF is in the shack when you use your system?


--
73 for now
Buck
N4PGW