Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1] 2 3 4 5 6 Next   Go Down
  Print  
Author Topic: Chameleon EMCOMM2  (Read 11274 times)
KK4CPH
Member

Posts: 154




Ignore
« on: January 15, 2013, 06:17:45 PM »

Anyone have any experience with the Chameleon EMCOMM2 antenna?  I'm just skeptical to the claims of a 60' wire being able to work 160-2m.
Logged
N4CR
Member

Posts: 1664




Ignore
« Reply #1 on: January 15, 2013, 06:27:54 PM »

Where's the specifications?
Logged

73 de N4CR, Phil

We are Coulomb of Borg. Resistance is futile. Voltage, on the other hand, has potential.
KK4CPH
Member

Posts: 154




Ignore
« Reply #2 on: January 15, 2013, 06:43:03 PM »

http://chameleonantenna.com/CHA%20EMCOMM%20II/CHA%20EMCOMM%20II.html

Hope the link works.
Logged
N4CR
Member

Posts: 1664




Ignore
« Reply #3 on: January 15, 2013, 08:10:03 PM »

It's likely a long chunk of wire with a connector on it. Maybe a big resistor too.

If it costs more than about $20 I'd just build an antenna that has actual gain specifications and a long track record.

The key to those specifications isn't what they put in, it's what they left out...

SWR specifications and gain. If you can't find that in the specifications, it's a no go.
Logged

73 de N4CR, Phil

We are Coulomb of Borg. Resistance is futile. Voltage, on the other hand, has potential.
K2DC
Member

Posts: 1354


WWW

Ignore
« Reply #4 on: January 16, 2013, 03:19:22 AM »

$125 Huh  I wish I get some of whatever they're on.

73,

Don, K2DC
Logged
KK4CPH
Member

Posts: 154




Ignore
« Reply #5 on: January 16, 2013, 04:47:30 AM »

I thought it might be a scam. I have a 90' piece of copper wire. Maybe I should just run it out to a tree and see what my results are. 
Logged
N4CR
Member

Posts: 1664




Ignore
« Reply #6 on: January 16, 2013, 06:34:31 AM »

It says it requires a tuner.

So, since we're talking about an antenna that is multi band and requires a tuner, I'll suggest one that you can build for 1/4 of that and is a proven performer.

Get yourself two pieces of copper wire 67.5 feet each. (add a foot to each end for foldback and twist.) If you want it to last a decade in the air, use stranded copperweld wire.

Make or buy some ladder line, enough to reach your shack. Anywhere from 600 to 390 ohm is fine.

Make or buy a way to join the ladder line to the two 67.5 foot pieces of wire. I use a Ladder-Loc.

Haul it up in the air as high as you can get it. Tie off the ends to something convenient. Try to keep the ends high enough that animals and people can't touch them.

This antenna will handle as much power as your balanced tuner can give it and will be easy to tune on many bands.

Have fun talking around the planet.
Logged

73 de N4CR, Phil

We are Coulomb of Borg. Resistance is futile. Voltage, on the other hand, has potential.
K5LXP
Member

Posts: 4475


WWW

Ignore
« Reply #7 on: January 16, 2013, 07:16:18 AM »

I'm just skeptical to the claims of a 60' wire being able to work 160-2m.

It all depends on how you define "work".  If you changed nothing of the description of that antenna and substituted a picture of a lawn chair for the photo, the "specs" are no different.  Without performance data it's up to the buyer to infer suitability to their application.  Most new/inexperienced hams only see the "Covers Band X to Band Y" and assume it performs *well* there, even if the opposite is true.  If the performance metric is that from 160M to 2M it doesn't catch on fire then it would meet the spec.  But it's not even spec'd for that.  We don't know what it can do other than what we assume from what little technical data is supplied.

A 60' piece of wire can be an efficient antenna.  Two features which will determine whether it will be *effective* is how well it's matched to the feedline, and where/how the wire is deployed.  The "matching box" for this thing is an unknown so without having one to test (since the manufacturer doesn't see fit to inform the consumer) it's all a guess.  From experience an untuned end fed wire without a radial field fed with an arbitrary "matching box" will have issues with power handling and common mode but may be usable (depending on user expectation) in some situations.  You can take your own 60' piece of wire and figure out if that will get you where you want to go for a lot less than $125.  If an end fed is what you're after you could look at the PAR end fed models which are built with quality parts to valid concepts, are priced somewhat less, and there are no hidden "features".


Mark K5LXP
Albuquerque, NM
Logged
WB6BYU
Member

Posts: 13171




Ignore
« Reply #8 on: January 16, 2013, 09:11:41 AM »

Actually they only rate it up to 6m, not 2m.

But of course a 60' wire can work over that range.  Just hook a big 100 ohm
resistor across the input and you will have an SWR of 2 : 1 or less, and not
even need a tuner.

Can you make contacts with it?  Sure.  I've made lots of HF contacts running
QRP at 2 to 5 watts output.  Some folks even go below 1 watt.  An antenna
with 10dB loss on a 100W transmitter is radiating more than that.


If you want to try building your own to see how well it works, wind a 4 : 1
un-un and stick a length of wire on it.  Or just hook the wire to the "single
wire" output of your antenna tuner.  (If your tuner only has a coax output,
put a banana plug on the end of the wire and plug it into the center conductor
of the SO-238 jack.)
Logged
WB6BYU
Member

Posts: 13171




Ignore
« Reply #9 on: January 16, 2013, 10:48:28 AM »

This is the link I was looking for to build your own version:

http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf
Logged
W5WSS
Member

Posts: 1694




Ignore
« Reply #10 on: January 17, 2013, 11:08:35 AM »

I used a auto tuner capable of high power applications at the shack window and just outside the shack window installed a fan of tuned sloped radials at 5ft height two per band 10m-75m traveling downwards in opposite directions to insulated anchors.

I used a banana plug into the SO-239 hole of the tuner
 a short wide strap out to the radial junction.

Differential mode was normal and common mode displacement currents around the station near field did not rise to problematic voltage levels noted before and after the radials were installed.

Noise ingress was noted before and after the radials and was dramatically reduced with the addition of the radials.

The radials were held in place tightly about 5ft away from the back wall of the house and elevated 5ft sloped downwards and simply were positioned parallel to the back of the house they were NOT grounded to earth but were isolated using anchors that are non conductive.

The antenna wire length I used depended on my pursuits, for example if I wanted to use 10m I could quick change the wire to a length better suited for manifested power in the lower toa such as the quarter wave rather than the half wave since there is not much noticeable difference in Field strengths as a function of antenna gain differences why not use a length known to be easier on the tuner and a better toa for the band of interest rather than limiting to one length?

Use a wander lead to a earthing rod and redirect the antenna wire when away or during thunderstorm potential to be safe.

I used the halfwave but  opted out for the 1/4 wave wire in every case.
 I always avoided the 1/2 wave from then on.

I pulled the antenna wire up and down quickly almost perfectly vertical orientation some slope angle but not enough to call it a slop er,with a rope long enough to be varied and made up some 1/4 wave wires and matched them minus needing a tuner. the tuner became an interesting way of experimenting with the differences between the 1/4 vs the 1/2 and longer and tuner and skywave signal evaluation.


I really enjoyed the performance from a summer cottage and the cost was about $20
I already owned the tuner.
Logged
ROB1955
Member

Posts: 10




Ignore
« Reply #11 on: January 17, 2013, 06:14:32 PM »

Before bashing that new product on this forum (or any other products) is there anyone here that at least bought the antenna and took the time to try it to see what he could get from it?

As usual I'm certain at 99.9999999% that NONE of you did. It's the same old sad story that we hear all the time here on eham.net or qrz.com of a guy that can build the same thing for less than $20 or know someone that used a 5W lightbulb as an antenna and made contacts or that a resistor is hidden somewhere in the base of the unit or someone can do better with a wet noodle or whatever other stupid story that you guys can come-up with. I'm so tired and fed-up of those insane and useless comments that are put on those forums every time someone or a company put a new product, idea or a simple article online!! It's so pretentious and disgusting.

Is that what the amateur radio hobby turn out to be in the recent years which is bashing and crapping on new ideas and new products that are btw made in United-States? It is disgusting to constantly have to read that vomit. What a shame!! If those guys (chameleon antenna) were designing crap and scam like some of you always like to insinuate then I don't think that they would have dealers in Russia, UK, Australia, New Zealand (I think), Germany, Canada, United-States, Sweden and probably some other places that I don't know (It's on there website).

For the guy that is suggesting to buy "PAR end fed models which are built with quality parts to valid concepts, are priced somewhat less," go for it and buy yourself enough PAR end fed to cover the entire spectrum for $20. I even found the website for you: http://www.lnrprecision.com/purchase/

Same thing happened with the guy that wrote an article on magnetic loop antenna about 2 years ago : http://www.eham.net/articles/26572
People in the forum were literally salivating at bashing his article without even trying the antenna themselves... Trolls as usual.

 
Logged
W5WSS
Member

Posts: 1694




Ignore
« Reply #12 on: January 17, 2013, 08:42:20 PM »

Carma Carma Carma Carma Carma chameleon..... Grin
Logged
W5WSS
Member

Posts: 1694




Ignore
« Reply #13 on: January 17, 2013, 08:48:42 PM »

Build the same thing for $20....Oh robroy the Chameleon is no Quarter wave Cheesy
Logged
N4DOV
Member

Posts: 52




Ignore
« Reply #14 on: January 17, 2013, 09:02:23 PM »

I like ROB1955 too am dismayed that when someone takes the trouble to try to find out information, they get a dozen replies and NOT ONE has any experience with the product, (including me !).
KK4CPH to get your question answered try Chameleon Antenna Forum or the Chameleon Yahoo user group

http://chameleonantenna.com/CHAFORUM/index.php

http://groups.yahoo.com/group/ChameleonAntenna/members
Logged
Pages: [1] 2 3 4 5 6 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!