[TowerTalk] problems with 10m COMTEK 4 sq unit

K3BU@aol.com K3BU@aol.com
Sun, 18 Mar 2001 17:03:12 EST


In a message dated 3/18/2001 15:19:50 Eastern Standard Time, Dinsterdog 
writes:

> 
>  From my experience of using the comtek system, I suggest first to measure 
F/
> B.  If you don't noitce any,  check the dummy load connection.  If it is 
> hooked up right, and you see the power dump varying across the band, then 
you 
> have some sort of array action going-  Also, look for a resonant jump in 
the 
> array vs were the individual dipoles are tuned.
>  
>  Sounds like you already know about these types of test, but just very 
> curious as to the spacing, dimensions of the dipoles, etc......can you give 
> some information regarding this???? 
>  
>  I have had a few years of experience with Comtek Systems and have found 
> their equipment to be very, very relaible- Maybe you got a hybred coupler 
> accidently shipped to you for the wrong band? Will be interesting to see 
> whats up-

Well, 10m unit behaves much differently than 160 and 80 ones I have, testing 
with noninductive resitors plugged right into the connectors. Never mind what 
is connected to the box. Coupler doesn't work on any other band, the "best" 
band is 10m, but it is all confused.

The array is quarter wave spaced 4 square of vertical (Al abt 1") tubing 
dipoles. They check out as modeled, no problem with coaxes, double checked, 
MFJ dipped, etc.
If the box will be OK (fixed ?) the question is can it handle radiators with 
abt 110 ohms impedances? Books say nothing.

Yuri

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