circular and linear polarisation C band

There is no way to get both in the same time; for circular you need to insert a dielectric plate inside the lnbf (can not be done on corotor feedhorn), for linear you remove the plate.

ValentinTM said:

any ideea how to receive same type of polarisation Circular and Linear on a motorised C band dish ?

Click to expand...

Hi, valentinTM of course there are some solutions to your question.

If this is referred to the 3.70m dish you told me times ago, the best solution it's using a dualfeed (one lnb H/V and one R/L with dielectric plate for circular) changing the feed ring with one as follow



Otherwise there are more professional solutions.

if you have the possiblity to control a polarotor, a combination of feedring+waveguide avcomm+lnb+polarotor would allow to you to do all the polarity (H/V/R/L) with the same lnb



Avcomm waveguide is a special pipe between feedring and feedhorn/lnb(f) that allow to have circular polarization without a dielectric plate and of course without the loss of gain induced by a plate inserted in the lnb.

With a big dish like your, I'd choose a dualfeed with R/L lnb on main focus and th H/V one on a lateral one :thum:

Interesting

Hve I any benefit if I choose this pipe?

harimau said:

Interesting

Hve I any benefit if I choose this pipe?

Click to expand...

Absolutly not.
Your Asian reference satellites (100°E,78°E,76°E,113°E...) have H/V C-band polarity.

Avcomm waveguide is useful on C-band satellites broadcasting in circular polarity (so most of Europe area) and smallest dish (2.40m/1.80m/1.50m) where continental signals are weaker.

ValentinTM said:

any ideea how to receive same type of polarisation Circular and Linear on a motorised C band dish ?

Click to expand...

Difficult set R/L polarisation satellites on a motorised C band dish .
only fix dish work R/L polarisation on a satellite
c-band lnb came with fiber plate & for old lnb you need a fiber plate c-band lnb
Try it your own R/L polarisation satellites on a motorised if you have time (first start this on a fix satellite then try others).

use a normal ku-band LNB + pipe & fit fiber plate in pipe
for ku-band make your own a fiber plate using a sim card's extra fiber extender .

harimau said:

Interesting

Hve I any benefit if I choose this pipe?

Click to expand...

These satellites are R/L polarisation receiveable in asia
depend on Beam coverage & large size dish .

L/R polarity
C-band
20.0E
30.5E Only (feeds)
40.0E
57.0E
90.0E
96.5E

Ku-Band
56.0E