When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero. Soooooooo
common sence says that the best antenna gain comes about when the anti
resonant point can be easily fed, welllll thats how my antennas work.
Unfortunatelly, the antenna was resonant on top band
but with a very low resistance so I have to start all over again. The
noise level did increase by 7 S units where modelling showed 9 dbi
gain ! Maybe I should use two radiators instead of the single one. O
well, I have to make changes so the anti resonance point is available
at top band. David, IT IS a topsy turvy world
so I am not available to listenning to the wobbly heads on the radio.
Oh shame for shame
Art

On Sep 25, 8:27*pm, Art Unwin wrote:
When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero.

Delusions of grandeur induced by a modeling program... :/
Just wait till you try to feed power to these marvels of technology
you have conjured.

"Art Unwin" wrote in message
...
When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero. Soooooooo
common sence says that the best antenna gain comes about when the anti
resonant point can be easily fed, welllll thats how my antennas work.
Unfortunatelly, the antenna was resonant on top band
but with a very low resistance so I have to start all over again. The
noise level did increase by 7 S units where modelling showed 9 dbi
gain ! Maybe I should use two radiators instead of the single one. O
well, I have to make changes so the anti resonance point is available
at top band. David, IT IS a topsy turvy world
so I am not available to listenning to the wobbly heads on the radio.
Oh shame for shame
Art

Uh, resistance? Are you talking about DC resistance? What about impedence?

You also stated, "Unfortunatelly, the antenna was resonant on top band but
with a very low resistance so I have to start all over again" after saying,
"maximum gain comes about when resistance aproaches zero." Which is it? Is
your low resistance good nor not?

On Sep 26, 7:49*am, "Rectifier" wrote:
"Art Unwin" wrote in message

...

When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero. Soooooooo
common sence says that the best antenna gain comes about when the anti
resonant point can be easily fed, welllll thats how my antennas work.
Unfortunatelly, the antenna was resonant on top band
but with a very low resistance so I have to start all over again. The
noise level did increase by 7 S units where modelling showed 9 dbi
gain ! Maybe I should use two radiators instead of the single one. O
well, I have to make changes so the anti resonance point is available
at top band. David, IT IS a topsy turvy world
so I am not available to listenning to the wobbly heads on the radio.
Oh shame for shame
Art

Uh, resistance? *Are you talking about DC resistance? *What about impedence?

You also stated, "Unfortunatelly, the antenna was resonant on top band but
with a very low resistance so I have to start all over again" after saying,
"maximum gain comes about when resistance aproaches zero." *Which is it? Is
your low resistance good nor not?

I feed antennas with a resistive feads without reactance, when it
becomes an impedance I retune or should I say the radio retunes
the antenna to make it resistive
to make it resistive

On Sep 26, 7:49*am, "Rectifier" wrote:
"Art Unwin" wrote in message

...

When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero. Soooooooo
common sence says that the best antenna gain comes about when the anti
resonant point can be easily fed, welllll thats how my antennas work.
Unfortunatelly, the antenna was resonant on top band
but with a very low resistance so I have to start all over again. The
noise level did increase by 7 S units where modelling showed 9 dbi
gain ! Maybe I should use two radiators instead of the single one. O
well, I have to make changes so the anti resonance point is available
at top band. David, IT IS a topsy turvy world
so I am not available to listenning to the wobbly heads on the radio.
Oh shame for shame
Art

Uh, resistance? *Are you talking about DC resistance? *What about impedence?

You also stated, "Unfortunatelly, the antenna was resonant on top band but
with a very low resistance so I have to start all over again" after saying,
"maximum gain comes about when resistance aproaches zero." *Which is it? Is
your low resistance good nor not?

No. I have difficulty in feeding near zero resistances. I opt to feed
high resistive loads without regard
to SWR I just do not want a reactive load for transmitting. For
receiving the low resistance or even impedance
really is of no concernl. When I design a antenna say for top band I
want the near zero resitive load point to be about
the low end of the broadcast band which allows for coverage of all the
top band but makes the 80 metre band centered around the zero mark!.
The beam that I am building is not aimed at small volume but of a 4
foot antenna of ultra lightness so I can use a a pan and tilt
mechanism as used with CCD cameras. By the way this particular antenna
is an attempt to make one continous lobe for 180 degrees of a narrow
width without nulls. If this is successfull I will then place a dish
reflector( probably about 3 to 6 ft diameter depending on weight)
behind it and call it a day for the winter.
I promised to make a antenna for somebody so this continual testing
game just has to come to a halt
Regards
Art
I understand your reluctance to move away from the term impedance but
I prefer to refer to resistance in the absence of reactance.

"Art Unwin" wrote in message
...
On Sep 26, 7:49 am, "Rectifier" wrote:
"Art Unwin" wrote in message

...

When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero. Soooooooo
common sence says that the best antenna gain comes about when the anti
resonant point can be easily fed, welllll thats how my antennas work.
Unfortunatelly, the antenna was resonant on top band
but with a very low resistance so I have to start all over again. The
noise level did increase by 7 S units where modelling showed 9 dbi
gain ! Maybe I should use two radiators instead of the single one. O
well, I have to make changes so the anti resonance point is available
at top band. David, IT IS a topsy turvy world
so I am not available to listenning to the wobbly heads on the radio.
Oh shame for shame
Art

Uh, resistance? Are you talking about DC resistance? What about impedence?

You also stated, "Unfortunatelly, the antenna was resonant on top band but
with a very low resistance so I have to start all over again" after
saying,
"maximum gain comes about when resistance aproaches zero." Which is it? Is
your low resistance good nor not?

I feed antennas with a resistive feads without reactance, when it
becomes an impedance I retune or should I say the radio retunes
the antenna to make it resistive
to make it resistive

OK Art. I hate to put it this way, but you really need to take a course or
two to get on the same page and be understood in these subjects. Even a few
nights with the ARRL Handbook may help bridge the gap.

For instance. With Lumped Constants, when inductive reactance and
capacitive reactance are equal, the circuit is in resonance. Any series
resistance in the circuit will become a significant load and result in loss.
In an antenna, there will be a characteristic impedance of the feed point.
Although it may include the loss resistance, other factors determine that
impedance. Since there are nodes of high and low impedance on the antenna,
the feed point may be modified or relocated for different impedance. Also
because of the nodes, there will be high and low currents along the antenna.
Where the current is high, the losses in the resistance will be greater and
most greatly affect the Q.

On Sep 26, 10:52*am, "JB" wrote:
"Art Unwin" wrote in message

...
On Sep 26, 7:49 am, "Rectifier" wrote:



"Art Unwin" wrote in message

....

When modelling antennas and also building them it is obvious that
maximum gain comes about when resistance aproaches zero. Soooooooo
common sence says that the best antenna gain comes about when the anti
resonant point can be easily fed, welllll thats how my antennas work.
Unfortunatelly, the antenna was resonant on top band
but with a very low resistance so I have to start all over again. The
noise level did increase by 7 S units where modelling showed 9 dbi
gain ! Maybe I should use two radiators instead of the single one. O
well, I have to make changes so the anti resonance point is available
at top band. David, IT IS a topsy turvy world
so I am not available to listenning to the wobbly heads on the radio.
Oh shame for shame
Art

Uh, resistance? Are you talking about DC resistance? What about impedence?

You also stated, "Unfortunatelly, the antenna was resonant on top band but
with a very low resistance so I have to start all over again" after
saying,
"maximum gain comes about when resistance aproaches zero." Which is it? Is
your low resistance good nor not?

I feed antennas with a resistive feads without reactance, when it
becomes an impedance I retune or should I say the radio retunes
the antenna to make it resistive
to make it resistive

OK Art. *I hate to put it this way, but you really need to take a course or
two to get on the same page and be understood in these subjects. *Even a few
nights with the ARRL Handbook may help bridge the gap.

For instance. *With Lumped Constants, when inductive reactance and
capacitive reactance are equal, the circuit is in resonance. *Any series
resistance in the circuit will become a significant load and result in loss.
In an antenna, there will be a characteristic impedance of the feed point..
Although it may include the loss resistance, other factors determine that
impedance. *Since there are nodes of high and low impedance on the antenna,
the feed point may be modified or relocated for different impedance. *Also
because of the nodes, there will be high and low currents along the antenna.
Where the current is high, the losses in the resistance will be greater and
most greatly affect the Q.

I do not have any lumped constants. Maxwell's laws do not include
lumped loads only
distributed loads and my antennas revolve solely around the laws of
Maxwell which
being based on equilibrium includes all four forces of the standard
model
I have no problem with your suggestion, it is that I am just to busy
at what I do.
True ,you can feed at any point but there are penalties with that
aproach which I don't want to mess with,
I prefer to have continual tuning or adjustment at the antenna. Just a
reminder but my design is not
focussed around a planar form that concentrates on inter coupling of
radiators .
Best regards no offence taken
Art

"Art Unwin" wrote:
I do not have any lumped constants. Maxwell's laws do not include
lumped loads only distributed loads and my antennas revolve solely
around the laws of Maxwell which being based on equilibrium
includes all four forces of the standard model

Art:
Of course you have lumped elements in your "antenna". You have
a shoebox full of wire, fashoned into contra-wound coils. Also, the
tuning device you described is a variometer, again replete with COILS.
These coils constitute "lumped constants", as you call them.
Mistakes like this show that your equilibrium is tilted.

Mike W5CHR
Memphis Tenn

On Sep 26, 11:44*am, "Mike Lucas" wrote:
"Art Unwin" wrote:
I do not have any lumped constants. *Maxwell's laws do not include
lumped loads only distributed loads and my antennas revolve solely
around the laws of Maxwell which *being based on equilibrium
includes all four forces of the standard model

Art:
* * Of course you have lumped elements in your "antenna". You have
a shoebox full of wire, fashoned into contra-wound coils. Also, the
tuning device you described is a variometer, again replete with COILS.
These coils constitute "lumped constants", as you call them.
Mistakes like this show that your equilibrium is tilted.

Mike W5CHR
Memphis Tenn

If you say so
Rectifier
I am having a rethink on where to feed it aproach. Have to sleep on it
I will keep hold of that antenna but I am working on the winter one at
the moment
Regards
Art

"Art Unwin" wrote in message
...
On Sep 26, 11:44 am, "Mike Lucas" wrote:
"Art Unwin" wrote:
I do not have any lumped constants. Maxwell's laws do not include
lumped loads only distributed loads and my antennas revolve solely
around the laws of Maxwell which being based on equilibrium
includes all four forces of the standard model

Art:
Of course you have lumped elements in your "antenna". You have
a shoebox full of wire, fashoned into contra-wound coils. Also, the
tuning device you described is a variometer, again replete with COILS.
These coils constitute "lumped constants", as you call them.
Mistakes like this show that your equilibrium is tilted.

Mike W5CHR
Memphis Tenn

-If you say so
-Rectifier
-I am having a rethink on where to feed it aproach. Have to sleep on it
-I will keep hold of that antenna but I am working on the winter one at
-the moment
-Regards
-Art

I merely used Lumped Constants as an example to describe the relationship
between Inductive and Capacitive reactance, resistance, then to go on and
show how it is differently applied to antennas and impedance. Where to feed
it is exactly the point in providing a transition between the feedline and
antenna. For example: Lumped Constants in an antenna tuner not only adjust
reactance by providing the conjugate reactance to whatever is presented at
its input terminals, but also adjusts impedance, akin to adjusting where the
current minima and maxima will be in relation to the tuner's output
terminals. There are a great many ways to physically do that, either by
linear loading, lumped constants, transmission lines, transitions,
transformers. Look into the feed methods used for Yagis.