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Old Aug 18, 2014, 07:25 PM
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Joined Apr 2014
47 Posts
First off, awesome instructions, thanks.

I've attempted a REALLY cheap helical ($4 in parts) and gotten rather poor results. Was wondering how large the error margin allowances might be.

1280mhz
Vee antenna on 400mw Tx
4awg cu
All measured as close to your measurements as I could although it doesn't look pretty...

Unfortunately I don't have any wave testing equipment but I'm getting a similar ~1000ft range from the stock whips, Vee + whip, Vee + helical. Tests are done the same way and all on the ground.

I haven't gotten my T-connector yet and using 2.4ghz control; no notch filter; so no air tests yet. How much farther would air tests be?



Any and ALL help/advice/guidance is HUGELY appreciated. Thank you!
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Old Yesterday, 05:47 AM
Another one bites the Dust
United States, GA, Savannah
Joined Mar 2013
415 Posts
Quote:
Originally Posted by eatkabab View Post
First off, awesome instructions, thanks.

I've attempted a REALLY cheap helical ($4 in parts) and gotten rather poor results. Was wondering how large the error margin allowances might be.

1280mhz
Vee antenna on 400mw Tx
4awg cu
All measured as close to your measurements as I could although it doesn't look pretty...

Unfortunately I don't have any wave testing equipment but I'm getting a similar ~1000ft range from the stock whips, Vee + whip, Vee + helical. Tests are done the same way and all on the ground.

I haven't gotten my T-connector yet and using 2.4ghz control; no notch filter; so no air tests yet. How much farther would air tests be?



Any and ALL help/advice/guidance is HUGELY appreciated. Thank you!
What's the spaceing between the reflector and the element? Looks kinda large.
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Old Yesterday, 10:39 AM
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Joined Apr 2014
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Originally Posted by shadowolfs View Post
What's the spaceing between the reflector and the element? Looks kinda large.
The very end of it is almost exactly 1cm or a bit under a 1/2 in. Don't remember reading what it's supposed to be or measuring it....
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Old Yesterday, 11:22 AM
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Switzerland, LU, Buchrain
Joined Aug 2006
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Quote:
Originally Posted by eatkabab View Post
The very end of it is almost exactly 1cm or a bit under a 1/2 in. Don't remember reading what it's supposed to be or measuring it....
This is surely a big problem. For the frequency you are aiming to, it should be 2.2mm above the reflector. See this online calculator. Try to stick to these measures and your result should be quite ok.

http://jcoppens.com/ant/helix/calc.en.php

HTH

Markus
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