Antenna opinions and suggestions (started with Tak-tenna)

[VK2FABS]

Just make sure it is out of the jeans pocket before firing the 1KW into it!

That has brought back childhood memories of holding the end of rabbit ear antenna to improve the reception on our TV and SW radio. Worked really well.

[VK2FABS]

Came across another compact portable vertical whip antenna system - Chameleon CHA Hybrid-micro + CHA Mil Whip + CHA Mil Whip Ext. Good for 1.8-54MHz and weighs less than 3lb. Not cheap when all three components are combined.
http://chameleonantenna.com/PORTABLE%20 ... MICRO.html
http://chameleonantenna.com/PORTABLE%20 ... 20EXT.html

What I am curious is, what's the design of this antenna system? Isn't it just a loaded vertical whip? What's the secret ingredient to garner the good reviews on eHam? Anyone familiar with this product?

[VK2ZRH]

The "secret ingredient" is generally known as BE (aka BS).

Most "reviews" posted on eHam are not worth the paper they're not printed on.

Riddled with unarticulated assumptions. Litle or no explanation of technical or physical characteristics, circumstances or verifiable measurements.

The manufacturer's website explains little.

Look at the pretty pictures on the "Micro" website. The product looks rather like some wire wound on a plastic thingymabob, possibly for "storage". The lumpy object might be a balun of some sort. Perhaps. There's a clue about the antenna's characteristics:

The antenna will operate at all frequencies in the 1.8-54 MHz band without any adjustment with most modern external antenna tuners.

That leads me to believe that the product is only plug-n-play with an auto-tuner connected to your radio.

The CHA MIL EXT is, as the maker says, aluminium alloy tubing.

Seems to me you could save an awful lot of money kluging one up all by yourself. It's called "amateur ingenuity". Don't forget to use the auto-tuner with your radio.

[VK2FABS]

Yes Roger, I was a bit suspicious. the base "blob" could well be an 1:9 unun, similar to some of the other homebrew vertical antenna designs. Or is it a loading coil? But the product does look pretty solid. I also note that they "borrowed" military antenna design. It made me wonder if that indeed is the case? What magic does the military vertical whips have apart from being solid and heavy?

[VK3YE]

Yes Roger, I was a bit suspicious. the base "blob" could well be an 1:9 unun, similar to some of the other homebrew vertical antenna designs. Or is it a loading coil? But the product does look pretty solid. I also note that they "borrowed" military antenna design. It made me wonder if that indeed is the case? What magic does the military vertical whips have apart from being solid and heavy?

I'm reminded of a discussion of a T2FD broadband dipole antenna in one of Pat Hawker's columns (developed by the US Navy). Or others mentioning magnetic loops or loading up trees in the jungle - also often tried by the forces.

Apart from costing many times more than what your average short-armed ham would pay, I don't think there's much magic in military antennas.

However their requirements are different to ours. They insist on things (eg ruggedness, broadbandedness and ability to be set up quickly) that aren't so important to us. But they don't need worldwide communications from their portable stations. Instead good readable signals at a single hop is often enough. 20 to 100 watts gives enough margin even if antenna efficiency isn't great. If you're willing to sacrifice 3 or especially 6dB in gain then a broadband antenna is very easy to build.

Whereas we hams often want something that's cheap, high gain, efficient and with a low angle radiation for DX working. If QRP we want to be able to work the world with 5 watts. If QRO we want to be stronger than others to beat them to the DX. To get that gain (or to minimise loss) bandwidth is something we may have to sacrifice.

Horses for courses. There is no right or wrong. But military does not automatically mean good since requirements vary.

[VK2FABS]

Makes sense. So much to learn.

[VK5ZD]

Came across another compact portable vertical whip antenna system - Chameleon CHA Hybrid-micro + CHA Mil Whip + CHA Mil Whip Ext. Good for 1.8-54MHz and weighs less than 3lb.
....
What I am curious is, what's the design of this antenna system? Isn't it just a loaded vertical whip? What's the secret ingredient to garner the good reviews on eHam? Anyone familiar with this product?

I had a look at their website and, for a change, I don't think this company is making any extravagant claims (unlike some others). What users write in various reviews is another matter. If you look at the info on the CHA EMCOMM II antenna it tells you pretty much what you want to know:

The 'blob' is a 5:1 transformer.
An external tuner is required (this is in bold text).
It does not required any ground-plane but will perform better with one.
Results will vary with coax length and antenna elevation.
This antenna requires a robust ground system. If your ground is poor, the antenna efficiency will be poor, and you will be troubled with RF in the shack.

In the FAQ they say:

2 - DO I NEED TO USE COUNTERPOISE(S) WITH THE EMCOMM II?
YES & NO - The counterpoise(s) will always increase the antenna performances. They'll help to reduce the noise level and they'll increase the db in RX and TX. The EMCOMM II will be usable without them but the coax cable will be used as counterpoise by the antenna system which might create some RFI back into the radio and the shack.

Bottom line; wind a 5:1 transformer, get some wire and a tuner and DIY.

[VK2FABS]

Bottom line; wind a 5:1 transformer, get some wire and a tuner and DIY.

Well summarized!

[VK2OMD]

Came across another compact portable vertical whip antenna system - Chameleon CHA Hybrid-micro + CHA Mil Whip + CHA Mil Whip Ext. Good for 1.8-54MHz and weighs less than 3lb. Not cheap when all three components are combined.
http://chameleonantenna.com/PORTABLE%20 ... MICRO.html
http://chameleonantenna.com/PORTABLE%20 ... 20EXT.html

What I am curious is, what's the design of this antenna system? Isn't it just a loaded vertical whip? What's the secret ingredient to garner the good reviews on eHam? Anyone familiar with this product?

To take the first of your links... the user guide gives an expectation of SWR.

Note that the none of the characteristics are extreme, and the 'wire' one is benign.

That is not the characteristic of the wire itself, and since the 'magic' box is a fixed passive network, it is almost certain to contain a lossy transformer.

They did this with the CHA-250 for which I published an exposure / explanation of the 'magic' (which was the box and the requirement for a very tall mounting pole which turns out the be the main radiator).

Martin, G8JNJ did some field strength studies with the CHA-250 and confirmed model precictions.

This thing isn't a CHA-250, but it is from the same company and perusal of the user guide suggests a similar approach, and similar outcome.

If I had just 10W to play with, I would not be messing around with any of these magic low efficiency antennas.

Antenna advertisements are seductive to almost all beginners, and too many old hands.

If you want small antennas and performance, think VHF and above.

Owen

[VK2FABS]

Antenna advertisements are seductive to almost all beginners, and too many old hands.
If you want small antennas and performance, think VHF and above.

Lucky we now have the Internet and forums to cross compare reports and comments.

[KI6TRA]

I had a look at their website and, for a change, I don't think this company is making any extravagant claims (unlike some others). What users write in various reviews is another matter. If you look at the info on the CHA EMCOMM II antenna it tells you pretty much what you want to know:

Iain it's nice to see that someone is actually taking the time to read the User/Operator Guides and the documentation that is on Chameleon Antenna website. Thank you for pointing that out. No where the word "magic" or "secret ingredient" is mentioned on their website. Everything that need to be known is right there. If it's not then you can always go on the following links:

Forum: groups.yahoo.com/group/ChameleonAntenna/messages
YouTube Channel: https://www.youtube.com/user/ChameleonWalker
Facebook: https://www.facebook.com/CHAMELEON.WALKER?fref=ts
Email: support@chameleonantenna.com

You can read what a man with 60 years of Amateur Radio experience think about the EMCOMM II here:
http://www.eham.net/ehamforum/smf/index ... =showPosts

If their transformers were so lossy like some insinuate then Chameleon Antenna would probably not have produced more than 95% of their YouTube videos with low portable power (20W and less) like the following ones:

https://www.youtube.com/watch?v=0qzAmI0XWgY
https://www.youtube.com/watch?v=p1x9f6G2yt0

Anyway...Cheers,

-C

[VK3YE]

Iain it's nice to see that someone is actually taking the time to read the User/Operator Guides and the documentation that is on Chameleon Antenna website. Thank you for pointing that out.

Ummm - you just wouldn't happen to be the owner/manufacturer of Chameleon antennas?

http://www.qrz.com/db/KI6TRA and http://www.whois.com/whois/chameleonantenna.com look similar and mouseover at QRZ confirms it.

No where the word "magic" or "secret ingredient" is mentioned on their website.

'their website' or 'your website'?

Nothing against you posting about your products but we Aussies aren't as dumb as we sometimes sound and don't like people pulling swifties

[VK4WDM]

Simple does work. I had a vertical made with a 10m fibre-glass pole and wire, a 9:1 UNUN, ground-mounted with 12 radials. It tuned all bands with my internal tuner. 1500 QSO's in 12 months all over the globe, mostly with 30w of JT65, but also 100w SSB and some CW. Best fun I have had for years. Still use that system portable but have replaced it with a commercial metal vertical (Butternut HF-9V) at home QTH after the fiber-glass one was damaged by wind.

Other portable antenna is an end-fed wire - it works, and can be configured as a sloper or a vertical. Yes, it is a compromise, but like I keep saying to the OP, Get something in the air and improve later, you can't make contacts if the antenna is still inside your head (or jeans pocket).

Re military antennas. Totally agree with Peter Most of their HF field antennas are for NVIS but they are being largely replaced by satellite comms. For long-range HF they have base stations with very large yagis or log periodics.

73

Wayne VK4WDM

[VK2FABS]

Thanks Wayne. My first HF transceiver is now somewhere in the postal system and so are the various bits and pieces for antenna builds. There's still some time to brew ideas in the head...

[VK4WDM]

OK Weiyun, 15m is in great shape ATM and a 15m loop would fit your patio!

Report on the logger when you are ready to push the PTT button and we will all swamp your ears with music.

73

Wayne VK4WDM

[VK2FABS]

Can't wait!

[VK4TI]

Simple does work. I had a vertical made with a 10m fibre-glass pole and wire, a 9:1 UNUN, ground-mounted with 12 radials. It tuned all bands with my internal tuner. 1500 QSO's in 12 months all over the globe, mostly with 30w of JT65, but also 100w SSB and some CW. Best fun I have had for years. Still use that system portable but have replaced it with a commercial metal vertical (Butternut HF-9V) at home QTH after the fiber-glass one was damaged by wind.

Other portable antenna is an end-fed wire - it works, and can be configured as a sloper or a vertical. Yes, it is a compromise, but like I keep saying to the OP, Get something in the air and improve later, you can't make contacts if the antenna is still inside your head (or jeans pocket).

Re military antennas. Totally agree with Peter Most of their HF field antennas are for NVIS but they are being largely replaced by satellite comms. For long-range HF they have base stations with very large yagis or log periodics.

73

Wayne VK4WDM

Used to be a huge 125ft log periodic out the back of Oxley here in Qld , military comms but all down and sold off years ago

[VK4GJW]

Thanks Wayne. My first HF transceiver is now somewhere in the postal system and so are the various bits and pieces for antenna builds. There's still some time to brew ideas in the head...

So what did you end up purchasing? And what are the bits and pieces for? What type of antenna do you plan on trying?

[VK2FABS]

So what did you end up purchasing? And what are the bits and pieces for? What type of antenna do you plan on trying?

Ended up ordering an Elecraft KX-3. On the antenna and miscellaneous side, ordered a SARK100 Mini60 antenna tuner, various connectors/adaptors, cables (RG58/RG174), toroid, enclosure, BNC crimping tool and a 4200mAh LiFePO4 battery/charger. That should be enough to build a basic store for future projects. As suggested by many here, I'll start with an end fed long wire antenna, then gradually learn and try others. Suspect I'll need to work on a mag loop at some point. Saw annealed 3m copper tubing in Bunnings for $20 the other day and they are heavy. Whilst I understand that one needs to focus on a low resistance loop for mag loop antenna builds, I think I'll try some other material to minimise weight.

[VK4TI]

So what did you end up purchasing? And what are the bits and pieces for? What type of antenna do you plan on trying?

Ended up ordering an Elecraft KX-3. On the antenna and miscellaneous side, ordered a SARK100 Mini60 antenna tuner, various connectors/adaptors, cables (RG58/RG174), toroid, enclosure, BNC crimping tool and a 4200mAh LiFePO4 battery/charger. That should be enough to build a basic store for future projects. As suggested by many here, I'll start with an end fed long wire antenna, then gradually learn and try others. Suspect I'll need to work on a mag loop at some point. Saw annealed 3m copper tubing in Bunnings for $20 the other day and they are heavy. Whilst I understand that one needs to focus on a low resistance loop for mag loop antenna builds, I think I'll try some other material to minimise weight.[/quote]A fixed install can be copper , aluminum is light strong and works extremely well imho . its a few % lower in efficiency but making the loop a little bigger helps , at your low power a simple air cap from a broadcast radio will do although a butterfly is better , but if you want automatic tuning then plan for a vacuum cap when you upgrade , I have just taken delivery of a 500pg 10kv vacuum for a very reasonable cost and it will handle anything I am likely to throw at it .