HF Longwire aerial

A good item I recently saw used for that purpose was a "dog tethering steak" they look like a huge corkscrew and you can but them from a $2 shop for $5!? :) They will provide excellent surface area into the earth. Also don't use "a bit of wire" to connect the radio to the earth steak, get hold of some copper strap or heavy braid from a co-axial cable.

iirc a "long wire" technically needs to be at least a few multiples of the wavelength so as 8.022MHz has a wavelength of 37m your wire should, really, be 100m or so. Make it as long as you can and the tuner should do the rest. As someone else said; ensure it’s kept off the ground.

Mike Harding

One other thing worth mentioning (an old Sparkeys trick for getting an installation through the mains earth test in dry soils) pour water and/or salt into the area your earth steak is going and you may find that makes the difference between getting a signal out or not if you're marginal.

Mike Harding

You may find driving a stake into the dry ground to be not a very efficient earth (esp if it's solid rock). Another method is to use a "couterpoise"; a long length of wire draped along the ground, usually running on the ground away from the direction of the antenna. The wire doesn't have to be bare; the capacitance between the wire and the ground is sufficient to work as an earth. This is an old trick.
Gerry

We all try to improve aerial efficiency by making sure that the wire and the coils are as low resistance as possible, yet people use dirt for the counterpoise !

Comparative tests by the HFPack community have shown that a wire runnig a metre above the ground is always more efficient than "connecting" to "earth"

"Show me the money", Mike R :)

Forget that , where do these "earth steaks" come from ?

Robin Miller

You have to hammer a cow into the ground - it's not easy, I can tell you! :)

The 6924 has an inbuilt tuner.

Tony,
The 6924 has a built in antenna tuner, so no problems there.

I am about to re-crystal it to the main VKS freqs, and just want it as a backup unit.

Regards
Stu

Hi,

The built-in tuner may not be able to match a random piece of wire, especially if it is made to go with a certain length whip antenna. If that is the case, then there would be little benefit in using a wire at all.

As for a good ground, the cork screw dog thingy really would not provide a better earth than your truck used as a counter poise, except perhaps on the beach below the high water mark.

Cheers

Hl, the 6924 was designed to tune a random length of wire. Of course it will work much better if the wire is 1/4 wavelength at the operating frequency.

Cool, if that's the case. The only length of wire to steer clear of then is around 1/2 wave length. You will get very high voltages at the feed point and the tuner is unlikely to match it properly.

Cheers

Yep, I thought I recognised your style of posting.

Stu

Stu, style ? As in pedantic, bombastic and a PITA ? LOL Different world in here I'm afraid.

and they are only his good points lololol lmao

steve

Hi Phil. It would help if everyone got the terminology right here. A 8.88 metre length of wire is not a long wire on 8022kHz - See Mike Harding's post. What you are doing is tuning the wire as a 1/4 wave antenna. This uses the vehicle & capacitive coupling to ground as a ground plane. The purpose of the ground plane is to create an image of the tuned length of wire. This in effect makes a 1/4 wave antenna a 1/2 wave length, all be it with the bottom half replaced by the ground plane.
This is exactly how the mobile auto tune & tapped whip antennas operate.
Cheers, Tony

You're right Tony - thanks for the correction.