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Old Apr 24, 2012, 07:16 PM
At peace with his albatross
wannabe's Avatar
United States, CA, Vacaville
Joined Oct 2003
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Has anyone ever tried to encase there 5.8 helix in a sort of "radome" enclosure?

I am going to put mine in a plasic egg and wonder if that would have an effect on the antenna...
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Old Apr 24, 2012, 07:31 PM
Look Sideways at Polarisation
Funky Diver's Avatar
United Kingdom, England, Darlington
Joined Jun 2011
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Chucked together an excel spreadsheet to take out the guess work.

Get it here
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Old Apr 24, 2012, 07:34 PM
Look Sideways at Polarisation
Funky Diver's Avatar
United Kingdom, England, Darlington
Joined Jun 2011
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Quote:
Originally Posted by wannabe View Post
Has anyone ever tried to encase there 5.8 helix in a sort of "radome" enclosure?

I am going to put mine in a plasic egg and wonder if that would have an effect on the antenna...
I was looking at using plastic shot test tubes... for the active part
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Old Apr 24, 2012, 07:37 PM
At peace with his albatross
wannabe's Avatar
United States, CA, Vacaville
Joined Oct 2003
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Quote:
Originally Posted by Funky Diver View Post
Chucked together an excel spreadsheet to take out the guess work.

Get it here
Awesome !! Thanks for that effort!!

However it needs to be de-bugged. I got a support legnth of 3500.0" or 88900mm. Seems a bit long for 5.8.......
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Old Apr 24, 2012, 07:59 PM
Look Sideways at Polarisation
Funky Diver's Avatar
United Kingdom, England, Darlington
Joined Jun 2011
101 Posts
Quote:
Originally Posted by wannabe View Post
Awesome !! Thanks for that effort!!

However it needs to be de-bugged. I got a support legnth of 3500.0" or 88900mm. Seems a bit long for 5.8.......
Did you put in 5.8 by any chance?

Try changing it to MHz and you should be good

I will change it, but to put a prompt in for the right frequency range lol

edit : amends made
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Old Apr 24, 2012, 08:00 PM
At peace with his albatross
wannabe's Avatar
United States, CA, Vacaville
Joined Oct 2003
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Quote:
Originally Posted by Funky Diver View Post
Did you put in 5.8 by any chance?

Try changing it to MHz and you should be good

I will change it, but to put a prompt in for the right frequency range lol
HA, yeah that was it. I did 5800MHZ and got better results. Thanks!
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Old Apr 25, 2012, 09:14 AM
Always soldering
Joined Dec 2011
234 Posts
Hi guys!

I use a plastic toothpick container wich you can screw the cover to transport and then ones on the field you can unscrew that and use your helix without problems.

Off course my helix is only 3 Turns and very little weight for the connector to support.

Please note this original idea is from Lindsay (Pisces) and credits go to him for this simple and easy to get solution for our antennas.: Thanks Lindsay!

The reflector is directly "hot glued" to the bottom of the container.

Pictures attached...

Regards

Martin
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Old Apr 25, 2012, 10:04 AM
At peace with his albatross
wannabe's Avatar
United States, CA, Vacaville
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Yes but why bother removing the container bottom for use? Why not just leave the plastic cover on?
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Old Apr 25, 2012, 10:54 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
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^The cover will attenuate the signal and detune the antenna. If it were 900MHz, it wouldn't be a problem. 5.8GHz is very sensitive to the environment.

-Alex
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Old Apr 25, 2012, 11:00 AM
At peace with his albatross
wannabe's Avatar
United States, CA, Vacaville
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Quote:
Originally Posted by IBCrazy View Post
^The cover will attenuate the signal and detune the antenna. If it were 900MHz, it wouldn't be a problem. 5.8GHz is very sensitive to the environment.

-Alex
Okay thanks. What about paint on the active element?
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Old Apr 25, 2012, 02:58 PM
Look Sideways at Polarisation
Funky Diver's Avatar
United Kingdom, England, Darlington
Joined Jun 2011
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Quote:
Originally Posted by IBCrazy View Post
If it were 900MHz, it wouldn't be a problem
Apart from the fact that it'd be a dinosaur toothpick container then you'd have to worry about Pterodactyls getting your plane on landing approach
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Old Apr 26, 2012, 05:42 AM
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Joined Apr 2012
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Funky Driver,
Thanks for the spreadsheet. You summed up this thing for us... Every thing is clearer now.
But... Can you please explain what you mean with wood and with plastic in the former section.
Do you mean a plastic tube that you also given a link for example?
And wood also...
I am asking these questions because dimensions are changing when I change the material type... I am a little bit confused...
Is this change is related to the former materials conductivity, etc?
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Old Apr 26, 2012, 06:17 AM
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Joined Apr 2012
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Answer of my silly question is in the first page...
"Why the different calculations? The PVC former is a dielectric and shifts the frequency down 5% or so"
Sorry all!
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Old Apr 26, 2012, 07:31 AM
Happy Days
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United Kingdom, High Wycombe
Joined Mar 2001
4,261 Posts
Quote:
Originally Posted by IBCrazy View Post
^The cover will attenuate the signal and detune the antenna. If it were 900MHz, it wouldn't be a problem. 5.8GHz is very sensitive to the environment.

-Alex
Alex
What would happen if you put a 5.8 CL or SP inside a table tennis ball??
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Old Apr 26, 2012, 09:05 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
It will do fine. I actually recommend this to protect the antenna.

-Alex
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