The Hughes OMT...Practicalities of use

[Vipersan]

..So I offered up my Norsat Ka Band A to the OMT..
Yes it would fit ..the hole spaceings on the the flange are correct ...but Not possible to fit 2 lnbs ..
Ie one for H and one for V ..
There simply isn't space ..and the fitting of a right angled waveguide with WR42 flanges is also not possible unless one of the waveguide flanges was trimmed down.
A better solution would be 2 right angled waveguide to effectively widen the available space ..
Anyone fancy making 'em ..
Was that a no I heard ..lol
Still... a couple may one day turn up un ebay at a price that won't break my bank.
rgds
VS

 

[Vipersan]

..A quick question for anyone more knowledgeable about signal propagation through waveguides..
What would the effect be of allowing the OMT ports to seperate H and V ..but making the right angled waveguides out of circular section pipe ...then attaching these to the 2 lnbs ..
Would the 2 signals travel ok to the lnbs as Horizontal and Vertical ...or would there be significant losses ..due to perhaps standing waves or rotation within the circular section copper pipe ?
These I possibly _could_ construct ..out of 12mm copper pipe.
rgds
VS

 

[Topper]

I do not know much in the way of practicalities on that VS, nor do I remember much on wave propogation theory but digging back into my brain from over 20 years ago, I suspect you would have to experiment considerably with lengths as from what I vaguely remember, standing waves would only be created under certain conditions when the length of the pipe was incorrect based upon the frequency being received and whether it was exactly a first 3rd or 5th harmonic TBH I just cannot remember and a quick google search reveals this for an open pipe and this for a closed pipe but I doubt this will help you

 

[Vipersan]

Just found these on ebay so ordered 2 ...
They appear to be in 2 sections and hopefully this will make them modifiable to fit the lnbs ..
The fitting to the the OMT _should_ be straightforward .
rgds
VS
http://www.ebay.com/itm/RF-Microwav...6-5GHz-AN-0012-2-/131052147202#ht_2398wt_1093

As an observation ..
They DO appear to sell a lot of microwave stuff from Israel on ebay..

Oh and I'm not paying for them thanks to the winner of the Scottish National..
AL CO ..
I only backed it cos it was almost the same name as Christinas manufacturer ..
ALCOA

A throw away bet 50p E/W
There's justice for ya..
;)