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Re: W0LMD test results



Hi William and all others,

you get a RHCP in the same way as you would get it with the K3TZ
design.. flipping it over and solder it in place so it lookes
'mirrored'.

Circularity is achieved in the same way as for the K3TZ patch (better
explained for transmit case, but as patch is reciprocal works as well
for receive): the signal from the connector gets split up in two
components 90 degrees apart in orientation. One gets delayed by 90
degrees in time (either by a too short diagonal as in the K3TZ compared
to the second diagonal, or a tuning screw as for the W0LMD patch) and
therefore produces together with the non-delayed component a circular
wave.

And it does not have to be 90 degrees off.. look at the G3RUH patch..
actually W0LMD and G3RUH look almost exactly the same (except for the
scalar ring).. but physics should be the same, so am not very
surprised.. :-)


73s Achim, DH2VA





> Date: Thu, 26 Jun 2003 22:43:31 +0200
> From: "William Leijenaar" <pe1rah@hotmail.com>
> Subject: [amsat-bb] W0LMD test results
> 
> Hi AMSATs,
> 
> I see that I made some kind of "sandstorm" after I posted the message about
> my test results of the previous patch haha. I am very supprised that nobody
> else has descouvered that before, or made any notice of it.
> 
> Last week I was a little busy with qrl things. I have looked for the W0LMD
> patch information but like posted by some other amateurs I could not find
> any detailed information.
> Today I see some message posted with some links and I downloaded the
> drawings and after conversion to milimeters, and finding the materials I
> made the patch like drawn :-)
> 
> The patch is much better than the square patch. It is mechanical stable > and 
> also more circulair :-)
> Today I did some quick circularity tests and the best results I got is a > 2dB 
> difference. The test was done with the patch in my hand and rotate it, so 
> not very optimal, but still much much better !!!!
> 
> There is only one thing I can not find out. What is the polarisation of > this 
> patch ????
> I guess its LCHP, because its designed as feed in front of a dish, but > what 
> will be a RHCP design ???
> (The same confussion has been with the "square, none circulair" patch... )
> 
> Does anybody know the principle of creating circularity behind this design 
> ???
> Why this tuning bold is 0,5" from the feed point ??? (I would more think > of 
> 90 degrees to feed point)
> 
> Tommorow I will wake up early and will compaire my old patch with this new 
> patch...
> Then I will find out if this design is worth its glory .-)
> 
> 73 de PE1RAH, William
> - ---
----
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