Any Combined C/Ku feedhorn for Offset?

cl7teckie

Hi,

I am currently looking for a Combined C and Ku band Feedhorn meant for offset dish (f/D=0.6). However, this seems very rare. I would need one that is motorised/servo.

Please advise.

Thanks.

renibacterium

In USA there are conical feedhorns for 1.2m offset dishes that take a DMS Intl. BSC621 or BSC621-2 combined C/Ku band LNB.

Turok

the combinatation c/kuband in one lnb,over 14/18 voltage swichting,has very bad performance in kuband!
you cant change anything,the postion angle of the lnb is complitly fixed!
cband singal is okay!

renibacterium

Have you used a BSC621-2 ? They work very well on a corrently set-up large prime focus dish !

cl7teckie

Well, that's why I am looking for a feedhorn with separate LNB. I am looking at a feedhorn with servo, such that I can adjust the skew over the whole horizon. Thanks.

cl7teckie

Ya, there are quite a few good one for Prime-Dish. Seavey and Chaparral makes very good feedhorn for both combined C and Ku. But nothing for Offset dish.

Looks like I need to give up the idea of a Offset dish, and go for a 2.4m mesh prime dish instead...sighzz

Also, I do not trust those make-shift rings/cornical that modify the f/D of a feedhorn that is not from the feedhorn manufacturer themselve, or does not come with proper documentation, engineering drawing etc. I do not want to trial and error, as there is no current (other) solution for Offset dish.

luizimed

Hi,cl7teckie!
I don't speak english very well but I've underestood your "probem".
It's very easy to resolve it:

At first, u have to install your Ku-band(0.2dB, 60-70 dB gain) on your antenna and
try to track all Ku-band satellites (the most important are : the most eastern one,the central one -above your head- and the most western one.
Try to have the maximal signal strengh on all Ku-Satellites by adjusting the Df and the Ku-band polarity.
After that let your antenna go to most eastern satellite and look to your signal strengh and try to fix your other band( Single C-band 17°K like Diplosat) above or under the Ku-band (universal one) using rubber(scotch in French).
Your two bands must look at the same dot: the center of antenna.
Note: before fixing your second band, U have to imagine a line dividing your antenna in two equal parts. This line must be perpendicular to rotation axis of your antenna and the C-band must look to a dot on this line (above or under the antenna center (this dot must be very near of the focal point of antenna.
The two bands can approximatively the same Df (=focal distance).
Don't forget to adjust the C-band polarity by turning it left or right ad when U get
the best C-signal on C-satellites U have to attach(fix) the two bands very well using black electrical rubber BUT be careful : don't move Ku-band when fixing C-band