C band on an offset dish, what do I need ?

[kamaleon]

Great stuff Pedro. :-worship

So basically you're saying that without the scalar ring it works a lot better hey???

I still didn't understand: what do you call the face plate? I'm still confused. I'm not used to C-band terms :-crying

Pauxis not Nauxis, that sorts the mystery out ;)

No problem rolfw ;)

 

[guest poster]

Great stuff Pedro. :-worship

So basically you're saying that without the scalar ring it works a lot better hey???

I still didn't understand: what do you call the face plate? I'm still confused. I'm not used to C-band terms :-crying

Pauxis not Nauxis, that sorts the mystery out ;)

No problem rolfw ;)

We only threw it together to be honest when I had a spare few hours gap - the ring - face plate thing looks like a really cheap after thought of a scala ring (just 1) (see the other c lnb pictures above)... bit of tweeking and I'm sure we'd get a lot more out of it.. the same 1m dish was hitting very good numbers on ku on that sat before trying the c band lnbf.

OH... we took the 40mm holder off and made a very simple bracket to the 3" U bolt otherwise you'd never get the focus point etc...

 

[kamaleon]

I don't know what's wrong with me but I'm finding it extremely difficult to understand what you're saying???

"face plate thing"... scalar ring... are these the same thing for you?

I know what a scalar ring is, but I don't understand what you're talking about. The fact that I'm a C-band n00b probably doesn't help either, I know, but if you could make an effort and write complete sentences with a beggining, an end and full stops and commas...

cheers ;)

 

[guest poster]

I don't know what's wrong with me ......
.......edit....
cheers ;)

Know the feeling....

Sorry... see picture.. with it on.... the plate thing is not really a full feed horn with big scala rings as you'd expect on a C Band lnb- don't know what's inside though if there is more scala rings .. it is an LNB'f' though ..and it works...





Actually, the picute of the c band lnb above in this thread looks too high of the focus of the dish and its the scala rings that are in the way and causing the increased height so if a ku band lnbf were to be replaced the dish would be off sat if it was focused on that c band lnb. Ours still looks too high too.

 

[kamaleon]

Thanks a lot matey. As they say an image is worth more than a thousand words

I see now. Did the lnb come with a scalar ring too (not on the picture obviously)? Would anyone be able to explain what is this "plate thing" then?

 

[guest poster]

Thanks a lot matey. As they say an image is worth more than a thousand words

I see now. Did the lnb come with a scalar ring too (not on the picture obviously)? Would anyone be able to explain what is this "plate thing" then?

I think it's a basic scala ring .........&/or used for R/L reception...


ebay 180251047294 ActionAce007 ebay shop £11

 

[kamaleon]

I wonder if I can glad it on the side of a Ku LNBf on a motor'd dish as an offset?

Check this out mate:

http://www.satellites.co.uk/satelli...7-pictures-members-systems-17.html#post523840

 

[guest poster]

Check this out mate:

http://www.satellites.co.uk/satelli...7-pictures-members-systems-17.html#post523840

Thanks for that - really useful..

 

[kamaleon]

thanks to you for the good info you provided me ;)

 

[winterjo]

I have got an 1.8m offset motorisised dish with an corotor so I can watch KU and C band. In Austria a good adress is OLBORT.AT . I have my aquippment from him and it works fine, but I had to bild the holder for the corotor by myself. I have an Echostar receiver, because this is one of the less wich can handle a polariser and is an analog and digital receiver with CI Slots in one.

 

[CROSSBONES]

Here`s a Gibertini 1.5m on a Jaeger 1224 motor.

Channel master feed horn with Inverto and C-band lnb.

 

[guest poster]

How well do side by side lnbs actually work on a moving dish?

Last time we did it was about 10 years ago I think it was disappointing and only worked on a bit of the arc it was setup. The offset lnb will only be in the right place at one point on the arc (where it was set up and tested) and too high or low elsewhere on the arc even with being able to move the offset lnb to any satellite. It might work a bit haphazardly, but to do the C/KU thing on one dish without using a combi.. you have to use a system to swap the lnbs to the focal point or another system is to put the second lnb on top or below the main one and use an actuator for incline to also tilt the whole dish between lnbs at any given point on the arc as well as adjust for incline on some sats.

Anyone got more on this?

 

[BombedOne]

Plate thing is for receiving circular polarised signals (mostly russian satellites). Hovever, if you focus on these satellites, there's modification of that plate, which allows signal increase for 1.5-2dBi (equaling to dish change from 1.2m to say 1.8m). This applies ONLY to circular polarised signal, ONLY when using C band LNB on offset dish. If anyone wants, I have drawing for manufacturing such modified plate.

 

[kamaleon]

Welcome aboard (to the board)

 

[Turok]

i have tried with a tevlon plate,put it exactly in the same angle.then the normal dialectrikum plate,but normaly the signal should better with tevlon,but ,the singal was lower,arte they difrent types of tevlon on the market?

 

[BombedOne]

You tried to receive satellites with circular polarisation?

which one exactly?

 

[pipino]

here is an updated pictures of the same installation Crossbones mentioned Above
@pedro2000uk
if its well set it should work just fine ,i tested many cheap Dual polarity LNBs and the best result i got it with DMS "BSC421" just outperform Panorama ,jospel ...etc ,i fancy trying INVERTO TWIN C band LNBs ,any members try those??

 

[guest poster]

here is an updated pictures of the same installation Crossbones mentioned Above
@pedro2000uk
if its well set it should work just fine ,i tested many cheap Dual polarity LNBs and the best result i got it with DMS "BSC421" just outperform Panorama ,jospel ...etc ,i fancy trying INVERTO TWIN C band LNBs ,any members try those??

Those C band lnbs look like they have offset .6 f/d ratio feed horns, is that right?

 

[pipino]

Those C band lnbs look like they have offset .6 f/d ratio feed horns, is that right?

the offset feedhorn didnt come with the LNB ,originaly comes with flat ones for Prime focus dishes,and to be honest with you i dont realy know the F/D on those Feedhorn,the correct and optimum settings are done using the straight meter

 

[guest poster]

They look designed for offset c. .6. Prime focus feed horn would be flatter or actaully behind the entrance to the waveguide.

anyway looks great ...



might make a c band .6 feedhorn... we found the scala rings were best left off as they were too shallow to do any good and they worked better without.