Orthomode feedhorn

[Swamp_Rat]

A buddy of mine down here had a deal fall through for a bunch of Patriot dual c/dual Ku feedhorns fall through after he ordered them for a commercial customer and gave me a hell of a deal on one. I figured this may be a bit more user friendly (for the wife) than the setup I have now.
Anyway to make a lone story short I installed it Sunday morning and much to my surprise my quality dropped ten points or better across the board. My understanding was that these are considerably better than the corotor II I have now. I installed the c band lnb off my existing setup.
Is there any special setup for these or am I missing something?

 

[gabshere]

which lnb's did you use the ones off your corotor ?

i don't know if you would gain "frendliness" out of it but it should gain you the ability of multiple receivers viewing different polarities at the same time.

 

[Swamp_Rat]

I used the c and ku off my corotor plus added another set of the same.
I figured it would be a bit easier for my wife to use the free to air as she won't have to change polarity with the 4dtv, just switch input on the tv, change satellite and off she goes. There are several channels we both like to watch on c and ku on the fta.
I thought the orthomode feedhorns got so much better gain than the standard feedhorns.

 

[Cadsulfide]

can you get any more?

 

[pendragon]

I have an ADL dual orthomode feed, which is probably the same as yours (Patriot bought out ADL). From your signature, it sounds like you've mounted it on your 1.8 m Fortec. I'm a little different there because my dual ortho is on a 3 m Winegard, which is a much deeper dish than the Fortec. But I happen to have a C-band only ADL ortho feed on my 1.8 m Fortec.

There are a couple of things I've noticed that might be of help. The LNB mounting arms on the Fortec seem kind of long for the ADL single ortho feed. I had to modify them to get the feed close enough to hit the peak. I've seen the same thing on the 3 m with the dual ortho.

By chance yesterday I pulled the feed off the 3m to start an unrelated modification project (I will report on this in a separate thread). My changes affected the mounting dimensions, so when I put it back on, I started with it positioned approximately where Winegard recommends. By the time I was done with a quick peak, I had moved it slightly more than 0.5" closer to the dish. I'm going to look at this some more, but my working hypothesis is the ADL ortho feeds really like the focal point well inside the feed throat. The Corotor also likes the focal point inside, but nowhere near what I've seen on the ADL ortho feeds.

While there may be other issues you're seeing, I would pay close attention to centering the feed, trying a range of distance adjustments with the Fortec arms (don't slide the feed back and forth inside the scalar ring - that will throw off the f/D optimization) and making sure the feed is pointed dead center on the dish.

 

[Swamp_Rat]

he has something like 8 more. PM me for Jim's Number

 

[Swamp_Rat]

It is stamped ADL on the main body then the ku mount has Patriot on it so it probably the same animal.
The focal distance was pretty close as was the f/d ratio I thought. It was well centered but I considered the distance 1/8" in so maybe it needs a good bit more than that.
It was a quick try with the holiday and I threw my corotor back up. I will give it another shot this weekend.

Thanks