Mine works just fine. Been hanging in the weather for 9 years.

On Fri, 25 Feb 2005 02:08:10 GMT, Conan Ford
wrote:

"-=jd=-" wrote in
0:



All good advice and well taken, but if someone doesn't have the
interest or ability to wind their own transformers (to hear the
"ear-ball" effects of different kinds) and if they don't have a
noise-bridge or some way to measure/analyze their antenna, then there
will always be an element of "pure guess" involved to one extent or
another. In which case, just get the 9:1 or 10:1 and be done with it.
In other words, for the *average* listener, don't sweat the granular
details. Just rig something up and start listening! Most any random
wire/transformer combination (within reason) is better than a whip
antenna, or something inside the shack. Just my $.02 worth...

-=jd=-

It is much cheaper to wind your own transformers--a $5 torroid and $2 of
magnet wire, plus a few connectors and a box. It's either that, or pay up
$40 for a pre-built balun, and you don't know what winding method they used
(or how sloppy it is) since it's all potted in epoxy.

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
...
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon
wrote:

In article 9,
Conan Ford wrote:

Telamon wrote in
news:telamon_spamshield-D142D9.21371823022005@newssvr21-
ext.news.prodigy.
com:

In article 9,
Conan Ford wrote:

"MC" wrote in
t:

I've just replaced my old cable with some nice shiney new 50ohm
coax attached directly to my 100+ feet of longwire. As I still
want
to suck that little extra out of my antenna, I want to add a balun
but I am confused with this transformer ratio stuff. I realise
that a long wire has quite a high impedance. However, should I go
for a 1:4 or a 1:10 ratio balun. If I went for the 1:10 would it
be overkill and will it make any difference over the RF if I only
had a 1:4. I ask because I can get a 1:10 a lot cheaper than a
1:4.

Confused? I am :)

MC




1:9 is ideal for a longwire (ideal impedence is 450 ohms, matched to
50 ohm coax, so 50:450 = 1:9), so go for the 1:10. The 1:4 is for
something with lower impedence than a longwire.

Not all baluns are created equal, however. What frequencies are
they
rated for? This will depend on the turns count of the windings and
also on the ferrite material.

The impedance of the wire depends on the height above ground. The 1:9
is most likely best.


Is there a site that explains this, with a formula that can be used? I
found one once that was for a straight horizontal wire at a fixed
distance above a ground plane, but it wasn't for antennas... I just
assumed 450 ohm was a good value.

Assuming medium ground conductivity:

Wire impedance = 138 log (4 * height / wire diameter)

Height and wire diameter are in the same units.

An 18 gauge wire 10 foot off the ground would be around 560 ohms.

A transmission line is not a generator.

On Fri, 25 Feb 2005 17:55:07 -0800, "CW"
wrote:

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
.. .
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon

David wrote:

A transmission line is not a generator.

No kidding, 'tard boy.

Go take those meds, and try to be a little more coherent before you post first
thing in the morning.

dxAce
Michigan
USA



On Fri, 25 Feb 2005 17:55:07 -0800, "CW"
wrote:

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
.. .
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon

No ****.

"David" wrote in message
...
A transmission line is not a generator.

On Fri, 25 Feb 2005 17:55:07 -0800, "CW"
wrote:

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
.. .
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon

Transmission lines have characteristic impedance, non-frequency
dependent. Antenna impedance (original question) does have a
frequency component.

On Sat, 26 Feb 2005 18:25:12 -0800, "CW"
wrote:

No ****.

"David" wrote in message
.. .
A transmission line is not a generator.

On Fri, 25 Feb 2005 17:55:07 -0800, "CW"
wrote:

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
.. .
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon

May have been the orriginal question (actually wasn't, OP really didn't
understand the concept) but it wasn't where the conversation led. Try to
fallow along.

"David" wrote in message
...
Transmission lines have characteristic impedance, non-frequency
dependent. Antenna impedance (original question) does have a
frequency component.

On Sat, 26 Feb 2005 18:25:12 -0800, "CW"
wrote:

No ****.

"David" wrote in message
.. .
A transmission line is not a generator.

On Fri, 25 Feb 2005 17:55:07 -0800, "CW"
wrote:

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
.. .
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon

I followed it accurately. If the antenna is resonant (frequency) the
impedance drops to a value which is dependant on distance from ground.
Away from resonance the impedance goes high. The impedance of a
random wire is largely a function of frequency.


On Sun, 27 Feb 2005 10:58:57 -0800, "CW"
wrote:

May have been the orriginal question (actually wasn't, OP really didn't
understand the concept) but it wasn't where the conversation led. Try to
fallow along.

"David" wrote in message
.. .
Transmission lines have characteristic impedance, non-frequency
dependent. Antenna impedance (original question) does have a
frequency component.

On Sat, 26 Feb 2005 18:25:12 -0800, "CW"
wrote:

No ****.

"David" wrote in message
.. .
A transmission line is not a generator.

On Fri, 25 Feb 2005 17:55:07 -0800, "CW"
wrote:

Not for it's characteristic impedance. Does your coax have a different
impedance at different frequencies?

"David" wrote in message
.. .
Isn't there a frequency component?

On Thu, 24 Feb 2005 07:03:25 GMT, Telamon

DaviD,

In article .com,
"RHF" wrote:

DaviD,
.
The "Impedance" of a Random Wire Antenna is largely a function of :
- The Length of the Wire with respect to the Frequency Specified.

No. The length affects the reactance over frequency.

- The Height of the Wire above ground level with respect to the
Frequency Specified.

Yes. The height above ground and the wires diameter.

--
Telamon
Ventura, California