[Moon-net] Q. Measure for OM6AA round septum

[Edward Cole]

At 12:50 AM 3/9/2007, SM5LE wrote:
>Hi
>Does anyone have the measure (in mm) for the round septum (OM6AA) 
>described in latest (1/2007) DUBUS?
>Can I use the same the 4-step septum from OK1DFC? Why are 5 steps 
>better than 4 steps?
>I will use the measure only to fabricate one psc just helping a 
>friend to be 1296-EME-QRV.
>
>73 Super tnx de Sven SM5LE
>_______________________________________________

Sven,

Reading the article quickly, it appears that the 5-step septum plate 
resulted from computer analysis using Mican Microwave Analysis.  It 
appears that this improved Tx/Rx port isolation over the 16-dB 
achieved by Tommy, WD5AGO and analyzed by Paul, W1GHZ.  As Marko 
reported the article provides plentiful charts supporting the 
design's performance parameters but omits the dimensions of the 
septum plate.  It occurred to me that they may be anticipating 
marketing their design.  The article focused on obtaining a wide-band 
13cm feed, so I wonder if the 4-step design is adequate on 23cm.

I am building for 23cm (hopefully for summer of 2007) with aluminum 
skin 4.9m dish, and want to make a cylindrical septum feed.  I 
already have built a square OK1DFC feed.


73,
Ed - KL7UW
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