Portable whip antenna by Chameleon

[Ham4CW]

One of the portable antennas in use here is a collapsible whip antenna made by Chameleon. Because the system is modular you just buy what you need. There is a whip, a whip extension, a transformer which they call the Hybrid, there's a wire antenna, ground spikes, and so on...

Much of what I have here I obtained as a job lot of Chameleon items, though I did purchase the ground spike and capacity hat seperately.

The whole antenna can be deployed in minutes in most cases. This is not a resonant antenna, or should I say Chameleon did not appear to be aiming for any one band. Because of that you need to use an ATU with the whip system, and ideally the tuner should be connected as close as possible the the Hybrid transformer.

Some of my portable rigs have in-built ATUs, and for those that do not I have a Elecraft T1 QRP tuner. This I mount directly at the base of the antenna just using an PL259 to BNC adapter.

With the items in the photos below it is possible to set the antenna up as a vertical whip, or as a long wire. At a push you can use the whip itself as a support for one end of the long wire, and use a nearby tree or post as the support for the hybrid.

In whip 'mode' you can mount the antenna on the ground spike, clamp it to a table or balcony using the adjustable 'jaw' clamp, or maybe use the mirror mount to attach the antenna to another support rod or suitable vehicle part.

The whip has copied an idea used by the military for many years, that of having an internal bungee, so you only have to flick the antenna out and it assembles itself pretty much!

Chameleon items are all VERY well made but not the cheapest. Also, although this is sold as a portable antenna I don't think I would like to have to carry it for miles and miles since due to the rugged contruction the overall weight is fairly heavy when compared to say a simple wire antenna and unun.

Other than the weight of the antenna, especially if you decided to carry  all of the possible options, the antenna is excellent, and will save much lost time normally wasted buggering around tying to hook antennas through and over trees and such like.

Score: 9 out of 10 (1 lost only because of the weight of the antenna + options)

 

[MI0PYN]

Both Julian OH8STN and Gil F4WBY both use it and like it. See the RadioPrepper and SurvivalTech Nord Youtube channels for details but they both like them.

I wonder how it compares to something like the Buddipole Buddistick? Have you use one of those Mark?

 

[Ham4CW]

Yeah I've seen their channels, especially Gil, he has some excellent videos on there.  bd

He tends to push Patreon a bit too much these days though. :-X

I think that on the lower bands a Buddipole (dipole version) would out perform it due to the antenna being resonant and having a much higher current across the center of the antenna (until you get to the loading coils). Whereas the Chameleon is non-resonant, you are relying on the 9:1 Un-Un and your tuner to use brute force feeding!

However, when you get to the Buddistick things might be more of an even match since both antennas require a counterpoise wire, and unless matched/tuned correctly you will get earth losses galore.

Also, the Buddistick is center loaded and on the lower bands especially it will have quite a low feed-point impedance, that coupled with a non-resonant counterpoise could equal poor efficiency.

The Chameleon though, because it is short compared to the wavelength will have a higher (capacitive) reactance, but with the Un-Un in place it is as though you are feeding one long antenna (whip + counterpoise). It could be thought of as an OCF dipole.

The whip + earth rod combo is pretty poor, but once the counterpoise is attached and the length adjusted to suit, you can get quite a good SWR dip, which in turn points to an improved efficiency. It also helps fitting a choke in the feeder, because as you are feeding it off center you will get current flowing on the braid if you don't, which messes up any radiation pattern you might hope to have, and in turn means more losses.

As i mentioned in the first post, I mount the tuner at the feed-point to minimize losses. I think one of Gil's video shows him trying to use the whip with the tuner by the radio, and the results were rubbish. Later in the video, or possibly the next video he uploaded, he mentions that the poor results were due to mounting the tuner  by the radio and using a long coaxial feed from there to the antenna. Most of his signal is being absorbed by the feeder due to the massive mismatch.

Theoretically there are losses even when mounted directly on the connector, but it is way less than the losses you will get if you had say 15-20 of feeder in between the two. I only normally tinker with QRP levels so there is no issue with sitting right next to the whip antenna, or even the magloop mentioned elsewhere on here.

If you look in the photo you can see what looks like a large skeletal clover leaf, that is a capacity hat. However, for some reason instead of having the 'hat' fit on the top end of the whip where it would improve efficiency the most, they decided to have it mounted just under half way up the antenna. :-*

When measured with an antenna analyser you find it gives an improved resonance around the 6m band, but helps VERY little anywhere else. pq

Because it is all modular you could for example clip a wire on to the top of the vertical section and use the whole structure as an inverted L.

I think it's one of those antennas that would be fine for say a week away, thus allowing time to perfect the counterpoise length and/or add a top wire, but for quickness and ease of use the magloop beats it hands down every time.

If I were to consider another rigid portable antenna it would be a Buddipole, because of the better efficiency mentioned above. Having said that though you do have to tune the Buddipole to resonance to get the best out of it, and because it is an inductively loaded antenna the bandwidth is likely to suffer.

All of these antenna have good and bad points, every one of them is a compromise of portability against practicality.

My ideal is always to try to find some way to deploy a resonant antenna, rather than fudge the matching with a coupler. bd

73... :w:

*EDIT* Forgot to mention, I do have a Diamond HFV5 loaded/portable dipole that covers five bands, but that's another story!