Baluns?
 

Dave Platt wrote:
On the other hand, if the feedline-path reactance is capacitive, and
happens to be close in absolute value to the inductive reactance of
the choke... then you've got a series-resonant circuit.

This is one reason why an ugly choke only works well over
approximately a 2:1 frequency range. Below that range,
the inductive reactance is too small and above that
range, series resonance defeats the purpose.
--
73, Cecil http://www.w5dxp.com

Baluns?
 

JB wrote:

...
The Devil deceives many and jeers at the truth. But those who call on the
Lord in prayer keep him at bay. The sun shines on the wicked and the
righteous.



Is there some vending machine which dispenses such as you? Are you a
"Pod Person" that is grown from some plant from Mars and attempts to
mimic humans? Do you think you a member of the church of satan, are
insane, and this motivates you?

You are an idiot with no shame, I will grant you that ...

Regards,
JS
Half-a-Brain-McCain'n Insane; So Lawdy Mama, It Looks Like Obama!

Baluns?
 

Dave Platt wrote:

...
I saw an interesting talk at a local ham-club, at which the presenter
gave an explanation for one reason that the "effectiveness may vary"
with these sorts of choke baluns.
...

In 1982, when I worked for Boeing, they flew us to New York to attend
some lectures ...

Anyway, I remember one guy who gave an hour-and-a-half talk, complete
with slides, charts, models and other presentation aids on why the
bumblebee can't possibly fly ... it was totally fascinating, the data
looked absolutely real!--even though everyone (well, most) in the room
realized they were being "put on."

To anyone who has wound and used a few dozen chokes/baluns/ununs of
varying designs, I highly recommend the "Bumblebee Lecture."

Now, I am off to watch a few bumblebees crawl about ...

Regards,
JS

Baluns?
 

On Aug 28, 8:45*am, Cecil Moore wrote:
Highland Ham wrote:
Also: *http://www.hamuniverse.com/balun.html*(many pictures)
================
Nice URL with excellent info

The problem with ugly baluns is their limited frequency
ranges. In the following measurements, the choking
impedance was over 1k ohms for only small ranges of
frequencies, 19-29 MHz, 10-22 MHz, 16-25 MHz, 8-16 MHz,
5-8 MHz - frequency ranges of 2/1 or less. HF covers
a 10/1 frequency range.

http://www.k1ttt.net/technote/airbalun.html
--
73, Cecil *http://www.w5dxp.com

I noticed the use of a lot of tie wraps. Its never a good idea to use
these exposed to sun light.



Jimmie

Baluns?
 

"JIMMIE" wrote in I noticed the use of a lot of
tie wraps. Its never a good idea to use
these exposed to sun light.

Most of the white tie wraps will not withstand sunlight. The black ones are
more UV ray resistant and do beter.

I sometimes use the white ones, but cover them with tape.
Scotch 33 tape.

Baluns?
 

dbc254 wrote:
Everyone makes fun of newbies buying ready-built dipoles on eBay, but
nobody can direct you to where to buy baluns? Searched hi and lo
online, and what I found, was more expensive than buying a ready-made
dipole! I'd like to buy a balun, and attach my own cut-to-length
wire, but can't find cheap baluns ANYWHERE.

Where are you Elmers buying your baluns?

Here are diagrams of one type of balun which will server you well:

http://assemblywizard.fr33webhost.com/balun1.jpg

http://assemblywizard.fr33webhost.com/balun2.jpg

You will need to pick the proper material you need for the core, and
compute the turns necessary for the freqs in question (lowest freq will
determine these), there are abundant design pages on the web ... google
is your friend.

Regards,
JS

Half-a-Brain-McCain'n Insane; So Lawdy Mama, It Looks Like Obama!

Baluns?
 

JIMMIE wrote:

I noticed the use of a lot of tie wraps. Its never a good idea to use
these exposed to sun light.
=============================
Black tie wraps contain carbon black and are hence UV resistant and
almost last forever.

Coloured or non pigmented plastic will indeed deteriorate due to UV
radiation.

Polypropylene rope , for example ,is usually coloured but never black.
Reason : If black it would not deteriorate due to exposure to UV ,hence
it would last far too long and the manufacturers would only need to
produce a fraction of their current production.
That's commercial life.

If you use rope other then polyester (sailing boats etc) try to find a
black plastic variety (not easy).
My 40 ft mast has (blue)polypropylene guys which need to be replaced
every 8 -9 years (even here in northern Scotland) ,but it is cheap
compared with polyester rope.

Frank GM0CSZ / KN6WH

Baluns?
 

"John Smith" wrote in message
...
JB wrote:

...
The Devil deceives many and jeers at the truth. But those who call on
the
Lord in prayer keep him at bay. The sun shines on the wicked and the
righteous.



Is there some vending machine which dispenses such as you? Are you a
"Pod Person" that is grown from some plant from Mars and attempts to
mimic humans? Do you think you a member of the church of satan, are
insane, and this motivates you?

You are an idiot with no shame, I will grant you that ...

Regards,
JS
Half-a-Brain-McCain'n Insane; So Lawdy Mama, It Looks Like Obama!

I will pray for you that your heart might be opened to Jesus some day. Then
with the blinders off you might truly discern the enemy and his devices.

"But I say unto you, That whosoever is angry with his brother without a
cause shall be in danger of the judgment: and whosoever shall say to his
brother, Raca, shall be in danger of the council: but whosoever shall say,
Thou fool, shall be in danger of hell fire." Mathew 5:22

Baluns?
 

JB wrote:
I will pray for you that your heart might be opened to Jesus some day.

Why would people who don't believe in magic antennas
believe in magic human beings?
--
73, Cecil http://www.w5dxp.com

Baluns?
 

JB wrote:
"John Smith" wrote in message
...
JB wrote:

...
The Devil deceives many and jeers at the truth. But those who call on
the
Lord in prayer keep him at bay. The sun shines on the wicked and the
righteous.


Is there some vending machine which dispenses such as you? Are you a
"Pod Person" that is grown from some plant from Mars and attempts to
mimic humans? Do you think you a member of the church of satan, are
insane, and this motivates you?

You are an idiot with no shame, I will grant you that ...

Regards,
JS
Half-a-Brain-McCain'n Insane; So Lawdy Mama, It Looks Like Obama!

I will pray for you that your heart might be opened to Jesus some day. Then
with the blinders off you might truly discern the enemy and his devices.

"But I say unto you, That whosoever is angry with his brother without a
cause shall be in danger of the judgment: and whosoever shall say to his
brother, Raca, shall be in danger of the council: but whosoever shall say,
Thou fool, shall be in danger of hell fire." Mathew 5:22



"John Smith" is certainly going to end up in hell, no doubt about that.
73,
Tom Donaly, KA6RUH