On 12/19/2014 2:33 AM, Jeff wrote:
By changing
the length of the coax you can make the antenna appear as being resonant
or non resonant, even though the antenna may or may not be a perfect 50
ohm load.

Incorrect, changing the length of the feeder will not change the SWR
beyond any extra loss in the cable. It will change the phase of the
mismatch that is all; (rotate around a constant VSWR circle on a Smith
Chart).

Jeff


Incorrect. The basic VSWR meter measures the voltage, not the power.
And if the SWR is other than 1:1, this voltage will change depending on
the distance to the mismatch.

Additionally, a shorted coax 1/2 wavelength long shows a short (0 ohms).
But a shorted 1/4 wavelength coax shows an open (infinite impedance).
Somewhere in between (I'm not going to bother to figure out exactly
where because it's not that important) it will show an effective 50 ohm
impedance.

Coax length is unimportant when you have a 1:1 SWR, but if you don't,
the coax will act as a matching network. And length will affect the
overall system.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 12/19/2014 10:14 AM, Jerry Stuckle wrote:
On 12/19/2014 2:33 AM, Jeff wrote:
By changing
the length of the coax you can make the antenna appear as being resonant
or non resonant, even though the antenna may or may not be a perfect 50
ohm load.

Incorrect, changing the length of the feeder will not change the SWR
beyond any extra loss in the cable. It will change the phase of the
mismatch that is all; (rotate around a constant VSWR circle on a Smith
Chart).

Jeff


Incorrect. The basic VSWR meter measures the voltage, not the power.
And if the SWR is other than 1:1, this voltage will change depending on
the distance to the mismatch.

Additionally, a shorted coax 1/2 wavelength long shows a short (0 ohms).
But a shorted 1/4 wavelength coax shows an open (infinite impedance).
Somewhere in between (I'm not going to bother to figure out exactly
where because it's not that important) it will show an effective 50 ohm
impedance.

Please bother. It is important to me to understand these things. And are
you saying that there is a length of transmission line that will satisfy
both the shorted and open conditions. What do you mean by "effective"?
Are the lengths different in the two cases? Please help and thanks.


Coax length is unimportant when you have a 1:1 SWR, but if you don't,
the coax will act as a matching network. And length will affect the
overall system.

Sorry Jeff, but you just shot yourself in the foot!
If you transmit a dead carrier and you don't say anything you are in fact violating the Part 97! All you people did was reaffirm what I had already said. The sad fact is that we give out licenses like lolly pops at a barber shop with no real instruction involved and once a person gets a license they automatically think that they don't need to know the rules or anything that they learned to pass the exam to get the license.
Had we had real Elmer's when we gave out those licenses, we wouldn't have 90% of the garbage we hear today on the HF radio!

As far as amplifiers goes, yes I can see someone using a amplifier on 160 meters in the summertime, but the rest of the time, all they are doing is broadcasting - not really serving any purpose.
If the OP bought a commercial OCFD in the first place - he wouldn't have these problems.

The people that made comments about their OCFD out performing a center cut dipole for X frequency doesn't understand how a OCFD works.
If you have a 80m OCFD and you use it on 10 meters, it acts like a 8 wavelength long 10m dipole. You actually get a realization of GAIN from the OCFD when you use it on 40 or 20 or 10m...

Unfortunately in my book to realize gain you must give up something in one direction to improve your signal in another. So the term GAIN really isn't relevant here. Instead of using the term GAIN I should say improvement, because improvement would be a more relative term.

Thank You - you just said what I was trying to imply!
The reason I use the term CB radio is because most people gets their start on the Chicken Band and you don't have to have a lot of intelligence to use something that only takes place on less then 1 MC of bandwidth.
You can practically cut a piece of wire to a resonant length and throw it up in a tree and not even use a piece of coax and talk on all 40 channels on a CB radio without a tuner.

When you become a ham and you want to talk everywhere, you must learn a little about feed lines and antenna's and what works and what does not and what a antenna tuner really does and what it cannot do.

The most hilarious people to me are the ones that uses non resonant antenna's, an amplifier and a antenna tuner and just because their signal is loud and strong they think that they can overcome being resonant.
They end up talking to other LIDS with the same situation and the only people they can hear are those that are the loudest!

I have owned a G5RV that I bought at a hamfest 4 years ago that was only out of the bag once, and even then only for one week.
The first time I tried to operate on 40m with it 20' off the ground, which was as high as I could get it on poles placed on my lot - everyone on 40m told me to get the heck off the G5RV, which was incentive enough to find something better and quit fooling around with junk!

As far as me not being a ham - you have your opinions and I have mine!
10-4 Rodger Dodger, I'm gone!

"Jerry Stuckle" wrote in message ...

On 12/19/2014 2:33 AM, Jeff wrote:
By changing
the length of the coax you can make the antenna appear as being resonant
or non resonant, even though the antenna may or may not be a perfect 50
ohm load.

Incorrect, changing the length of the feeder will not change the SWR
beyond any extra loss in the cable. It will change the phase of the
mismatch that is all; (rotate around a constant VSWR circle on a Smith
Chart).

Jeff


# Incorrect. The basic VSWR meter measures the voltage, not the power.
# And if the SWR is other than 1:1, this voltage will change depending on
# the distance to the mismatch.

But isn't it still Vmax over Vmin, regardless of where that happens on the
feedline?


# Additionally, a shorted coax 1/2 wavelength long shows a short (0 ohms).
# But a shorted 1/4 wavelength coax shows an open (infinite impedance).
# Somewhere in between (I'm not going to bother to figure out exactly
# where because it's not that important) it will show an effective 50 ohm
# impedance.

# Coax length is unimportant when you have a 1:1 SWR, but if you don't,
# the coax will act as a matching network. And length will affect the
# overall system.

I always understood the VSWR to be constant with the feedline length moving
the parameters around the Smith chart constant VSWR circle.

Thus it is possible by changing length to provide an antenna tuner with R
and X values that the tuner can handle better.

On 12/19/2014 10:38 AM, Channel Jumper wrote:
'Jeff Liebermann[_2_ Wrote:
;832323']On Thu, 18 Dec 2014 20:12:53 +0000, Channel Jumper
wrote:
-
I'm not quite sure, but I don't think that it is legal, according to
the
Part 97 to transmit a carrier without saying anything.-

Wrong.

Part 97.305(a)(b)
(a) Except as specified elsewhere in this part, an amateur
station may transmit a CW emission on any frequency authorized
to the control operator.

UH - he wasn't transmitting a CW emission, he was throwing a dead
carrier - can you read?

(b) A station may transmit a test emission on any frequency
authorized to the control operator for brief periods for
experimental purposes,...
YES - Brief Periods! 10 minutes is not a brief period!

http://www.hallikainen.org/FCC/FccRu.../305/index.php

Actually, you're half right. Much of what I hear on the air is
seriously lacking in content and only a little better than not saying
anything.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Sorry Jeff, but you just shot yourself in the foot!
If you transmit a dead carrier and you don't say anything you are in
fact violating the Part 97!

Please link to the FCC Rules and Regulations that specify such. Thanks.

On Fri, 19 Dec 2014 16:38:58 +0000, Channel Jumper
wrote:

If you transmit a dead carrier and you don't say anything you are in
fact violating the Part 97!

As long as you identify yourself at the end of the transmission (and
every 10 minutes), and not interfering with anyone, methinks it's
legal.

There's no lower limit on the speed of a CW transmission.
Let's do the math for the MINIMUM Morse code speed:
http://www.w8ji.com/cw_bandwidth_described.htm
1 / (0.002 WPM * 0.83 baud/wpm) = 602 seconds (10 mins)
So, if I were experimenting with ultra narrow band long range Morse
code or data transmission, that requires that I send very slowly, my
MINIMUM speed would be 0.002 words per minute before one needs to
identify.

Disclaimer: I am not an attorney.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Channel Jumper" wrote in message
...

Sorry Jeff, but you just shot yourself in the foot!
If you transmit a dead carrier and you don't say anything you are in
fact violating the Part 97! All you people did was reaffirm what I had
already said. The sad fact is that we give out licenses like lolly pops
at a barber shop with no real instruction involved and once a person
gets a license they automatically think that they don't need to know the
rules or anything that they learned to pass the exam to get the
license.
Had we had real Elmer's when we gave out those licenses, we wouldn't
have 90% of the garbage we hear today on the HF radio!

As far as amplifiers goes, yes I can see someone using a amplifier on
160 meters in the summertime, but the rest of the time, all they are
doing is broadcasting - not really serving any purpose.
If the OP bought a commercial OCFD in the first place - he wouldn't have
these problems.

The people that made comments about their OCFD out performing a center
cut dipole for X frequency doesn't understand how a OCFD works.
If you have a 80m OCFD and you use it on 10 meters, it acts like a 8
wavelength long 10m dipole. You actually get a realization of GAIN from
the OCFD when you use it on 40 or 20 or 10m...

Unfortunately in my book to realize gain you must give up something in
one direction to improve your signal in another. So the term GAIN
really isn't relevant here. Instead of using the term GAIN I should say
improvement, because improvement would be a more relative term.



Yes, I got my ham license out of the same Cracker Jack box that I got my
First Class Phone license out of around 1972.

The OCF I have is home built, but the blaun was bought. It does not take
too much to add about 40 feet of wire to one side and 80 feet to the other
side.

The testing I did was on 80 meters around 2 or 3 in the afteroon. The band
was almost dead, Not a signal within 50 khz of either side of where I was
testing. I did ID and ask if the frequency was in useseveral times during
the test.

Ham radio is partly for testing and experminenting. That is what I was
doing for about the 10 minuits total.

You can look in the books and theory and everything else, but unless you put
up several antennas and compair them in the same area like I have , it is
all just a guess. The ground, trees,and atmosphere are almost impossiable
to modle on a computer for every location. The OCF I was compairing was to
an 80 meter dipole on 80 meters only, not other bands. Without being able
to rotate an anenna, you have to take what you get as far as where the main
lobe of the signal goes.

Most of the ones that complain about amplifiers not being needed are the
ones that don't have one,but wish they did. I seldom run one,but at times
it does make a big differance in making good contacts and not. Same as with
a beam. People with poor antennas say they can work all they can hear,but
they do not realise they are not hearing much either. I don't knock people
with poor antennas. At one time I did not have a very good antenna system
either. Lived on a small lot without any trees and the best I could do was
a dipole up about 20 feet. Still had fun with what I had.

The name is real and the call is KU4PT, unlike some that post on here witout
a real name or showing a call.



---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

On 12/19/2014 12:10 PM, Wayne wrote:


"Jerry Stuckle" wrote in message ...

On 12/19/2014 2:33 AM, Jeff wrote:
By changing
the length of the coax you can make the antenna appear as being resonant
or non resonant, even though the antenna may or may not be a perfect 50
ohm load.

Incorrect, changing the length of the feeder will not change the SWR
beyond any extra loss in the cable. It will change the phase of the
mismatch that is all; (rotate around a constant VSWR circle on a Smith
Chart).

Jeff


# Incorrect. The basic VSWR meter measures the voltage, not the power.
# And if the SWR is other than 1:1, this voltage will change depending on
# the distance to the mismatch.

But isn't it still Vmax over Vmin, regardless of where that happens on
the feedline?


Yes, but that changes along the coax, depending on the length from the
mismatch.


# Additionally, a shorted coax 1/2 wavelength long shows a short (0 ohms).
# But a shorted 1/4 wavelength coax shows an open (infinite impedance).
# Somewhere in between (I'm not going to bother to figure out exactly
# where because it's not that important) it will show an effective 50 ohm
# impedance.

# Coax length is unimportant when you have a 1:1 SWR, but if you don't,
# the coax will act as a matching network. And length will affect the
# overall system.

I always understood the VSWR to be constant with the feedline length
moving the parameters around the Smith chart constant VSWR circle.

Thus it is possible by changing length to provide an antenna tuner with
R and X values that the tuner can handle better.



No, VSWR is not constant along the length of the feedline.

A transmission line connected to a load of a different impedance will
act as an impedance transformer. The actual impedance at the source
will be different than that at the load, depending on the load
impedance, the transmission line impedance and the length of the
transmission line. This is why changing the length of the coax allows
the tuner to work better.

Also since impedance is a function for the R and X values, when these
change, the impedance changes.

Yes, changing the length of the coax does move the parameters around the
Smith chart in a circle, but it is not a constant VSWR circle. Plot it
out and you will see the impedance changes, depending on the length of
the coax.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 12/19/2014 10:14 AM, Jerry Stuckle wrote:
On 12/19/2014 2:33 AM, Jeff wrote:
By changing
the length of the coax you can make the antenna appear as being resonant
or non resonant, even though the antenna may or may not be a perfect 50
ohm load.

Incorrect, changing the length of the feeder will not change the SWR
beyond any extra loss in the cable. It will change the phase of the
mismatch that is all; (rotate around a constant VSWR circle on a Smith
Chart).

Jeff


Incorrect. The basic VSWR meter measures the voltage, not the power.
And if the SWR is other than 1:1, this voltage will change depending on
the distance to the mismatch.

Additionally, a shorted coax 1/2 wavelength long shows a short (0 ohms).
But a shorted 1/4 wavelength coax shows an open (infinite impedance).
Somewhere in between (I'm not going to bother to figure out exactly
where because it's not that important) it will show an effective 50 ohm
impedance.


With a short, an open, or with what kind of load?


Coax length is unimportant when you have a 1:1 SWR, but if you don't,
the coax will act as a matching network. And length will affect the
overall system.