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Old Mar 05, 2012, 01:35 PM
IBCrazy is offline
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Amherst, VA
Joined Jun 2006
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Quote:
Originally Posted by costi_n View Post
Hello guys. I wanna show you a simple method to tune your helix if you already have a SWR-meter or a professional VNA. For me that method works. I tuned the helix for a 1:1.2 SWR which is very good for a DIY antenna .
After building the antenna from mictronics thread on FPVlab

http://fpvlab.com/forums/showthread....Y-5.8GHz-Helix

I found that is very difficult to move the wave trap to the first turn to find the best match. I tried for several times, I found the best place for wave trap, but after secured the solder, the match was gone so...I cut a little piece of FR4 board, about 3X4mm, put down on the reflector under first turn and move slowly forward and backward to find the best match. Pay attention not to touch the turn with FR4 board piece. If you are still not able to find the best match try to move the feed point higher or lower. For me that method worked.
That's a really good idea! I never thought of moving the base plate. I always moved the first 1/4 turn. I need your name because this matching technique deserves your name on it.

-Alex
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