[amsat-bb] Re: 1.2ghz helix

[Luc Leblanc]

On 29 Oct 2008 at 2:58, w7lrd at comcast.net wrote:

> I am almost finished with a 16 turn helix for 1.2ghz.  I am not sure of what type of matching I should use.
> Some of designs I have  seen use a flat tab on the first 90 degrees of the helix.  What size should it be?  Is there a better way?  I > have a bird 43 with a 1.2 slug for tuning.
> 73 Bob W7LRD
> 
Here is a clever way to match an helix  http://helix.remco.tk/  For 1.268Ghz a 3" tube od with caps seems to fit near the formulas 
dimension. The problem is the stub foil dimension on 1.268Ghz could be a pro rata of the S band will be good enough?

Experts idea are welcome with figures for a L band model




"-"


Luc Leblanc VE2DWE
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