Auto tune antenna length, bigger better?

Yep a 2 metre s/s whip works for me.

Cheers

Yes a horizontal antenna will always work better than a vertical one.
When camped up a 2 meter length of wire tied to a handy tree with nylon rope works really well off the top of an autotune.

Top of the the whip or auto tune body?

Screw the whip off and hook the wire onto the autotune's screw. I carry an 8.8m length of thin insulated wire (probably 8A or such) - it suits 8022MHz, but will still work down and up a bit on the channel scale - for 14M+ frequencies I just go back to the long SS whip (the autotune baulks at high frequencies on long wires). I have a crimp on ring soldered to each end of the wire - one end simply hooks over the autotune's screw - the other takes an ocky and goes into a nearby tree........ re orientation..... the ideal seems to be having the wire elevated (30-45 degs etc.) and pointing away (180 degs) from the station you are trying to reach ! I'm told most of the signal comes off the side of the wire, hence a strong outgoing to the ionosphere, in the direction you want to go. I'm also told that if there is nothing to hang the wire on, trailing it along the ground, still pointing away, can be effective. If time permits, tossing a rope over a tree branch and pulling the wire up can be worth the effort (you have to have something to do, while the fire gets going :-o). Re safety and 'wireplay' - make sure nobody is touching the wire when you hit the talk button ! Lot of energy going out !

"Yes a horizontal antenna will always work better than a vertical one. "

No, it depends on what distance you're working. If you're communicating under 500km you want a horizontal antenna.

If you're talking East Coast to West Coast you want a vertical antenna.

A Codan Autune has a long coil of wire inside and its effective length is adjusted by moving a ferrite or aluminium slug inside it.

A Barrett Autotune switches in additional wire wound onto donut-shaped ferrite toroids.

So... the wire inside is a radiator?

Didn't think a choke was classed as a radiator.

So I take it the Codan autotune will increase the length of the antenna mechanically.

So using you theory I could transmit comfortable with out a antenna connected to a autotune and it would make very little difference.

And i take it this was wrong as well....
"All a auto tune antenna does is fools the transceiver into thinking it has a matched antenna to transmit through, an auto tune does not act as a substitute for a right length antenna or increase performance."

"So... the wire inside is a radiator? Didn't think a choke was classed as a radiator. "

How do you think a tapped-whip antenna works at its lowest frequency ? It's a long coil - just like a choke.


"So using you theory I could transmit comfortable with out a antenna connected to a autotune and it would make very little difference. "

Yes, a Codan Autotune will tune up at the higher frequencies. Of course it'll make a difference if you remove the tip, you've shortened the total antenna length.



"And i take it this was wrong as well...."All a auto tune antenna does is fools the transceiver into thinking it has a matched antenna to transmit through, an auto tune does not act as a substitute for a right length antenna or increase performance."

That statement is correct, but there are many ways of making the antenna present close to 50 ohms to the transceiver - some radiate well, some don't. The reason the Codan has a reputation for good performance is because a lot of the tuning system becomes a radiating part of the antenna. There was an expensive broadband antenna sold years ago that was just a dipole with a 50 ohm resistor across the terminals !