NO Ground 27 MHz antenna

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Hmmm.. Are you asking about cancelling reactance and achieving a balanced impedance? Because a balanced system is one where the antenna circuit is tuned to resonance, right?

A shortened antenna is going to have capacitive reactance, and an antenna that is longer is going to have inductive reactance.

The reactance can be tuned out using the proper matching network, which would give you a balanced impedance ratio...

Or, are you talking about a balanced feed system using a ladder line?

Cause a coaxial feed is always going to be unbalanced.

I'm not sure what you're driving at because all antennas are going to be unbalanced somewhat... it's why we use matching networks.

 

Baluns explained
The word balun is shorthand for a balanced to unbalanced transformer. Antennas can be balanced or unbalanced. A balanced antenna is symmetrical about the feed point (e.g. a dipole) whereas an unbalanced antenna is not systematical about the feed point (e.g. a Windom). In the real world all antennas are unbalanced to some degree. Likewise feeders can be balanced (e.g. open wire line) or unbalanced (e.g. co-axial cable). When a balanced antenna is to be fed with co-axial cable, a balun is often used at the feed-point to provide a balanced to unbalanced transformation.

Common mode current is current traveling on the ground of the coaxial feed and returning to the transmitter, a really undesirable situation.

Yes?

 

No

No

Not really.


There is a capacitance to the radiating system, adding capacitance shortens both sides of the radiating system, adding induction adds to the length.

No, a tuning network aids the matching of the feed point impedance, it doesn’t replace the antenna system or add to the efficiency.

That’s where I’m coming from, ladder line is one form, any two wire feedline is part of a balanced system.

Not always true, you can setup a coax system as a balanced system.

My point is this (I’m not awake because I’ve been dealing with bs family issues).


A sinusoid wave is energy.

Moving it requires efficiency in all systems.


Like any other system, there are two factors involved with energy transfer from the amplifier to the ether.


One is current movement and the other is voltage movement


Every movement has two parts, one is outgoing and return (remember if you did lab work for school you would have seen this), a complete circle.


Depending on the circuit, the energy can be absorbed or dissipated.


Moving forward …


Taking a simple balanced system, using an inductive coupling at the transmitter, you can follow the current and voltage paths, there is an outgoing and a return.


Setting up a simple feedline and antenna system, the antenna total is ½ wave, the feedline is a ¼ wave for peak efficiency of transfer energy.


This allows equal flow of energy forward and return.


I am not talking voltage or current fed antennas.


There are hundreds of images for this example on the Internet thingy of what I’m saying,


A few factors involved for efficiency, an important one is the impedance at the feed point inception point, at the antenna inception point and especially the antenna radiating elements, it changes depending on the point of measurement.


The forgotten importance of the radiating element impedance seems to cause issues when we are talking about antennas that are not a full ¼ or ½ wave antenna (for example a coil loaded antenna).


So the issues you brought up first about counterpoise.


This does not nor ever existed in a mobile application.


What it really is, is a reflective system unattached to the antenna system to improve RF energy transmission in dipole systems. The term is used in vertical antenna systems (for example Hy-gain AV-680) when radials are installed but really isn’t correct.


Second - What people don’t understand is the mobile antenna system can be balanced per se (improved signal transfer efficiency) by having a proper rf ground taking in consideration the change of impedance of the antenna system. While people focus on the radiating element, the need for the other half of the system to be as close to the radiating element impedance and other measurements because of the flow of energy. this is not a reflecting element.


The relationship between the two allows the efficiency of the entire system to be improved.


Third - The reflection of the signal is related to the capacitance of the vehicle and the earth. This is an entirely different subject.


Common current mode is a form of imbalanced energy flow. It can be used when there is no means of balancing the entire system. Taking advantage of using all or part of the feedline as part of the antenna, just like … G5RV and other antennas schemes seem to make use of this.


I know this is incomplete thoughts but it should show you where I’m coming from.

 

No response?

wow!