How to improve reception(diy solution) on 120cms for astra 2 uk beam

[rodscha]

I read some time ago that a "ricotta pot" could be used as a protective cap(rain or shine) on a single Ku band LNB ,on an offset dish.
Looking at its shape,could it also work as a primitive "feedhorn",covering it in metal/or making it in aluminium etc?
My objective would be to gain a few dbs on fringe reception which in my region is pretty jumpy when high pressure goes away.
I see a lot of people in India use makeshift objects of the like.
Any comment?

 

[ozumo]

I think you mean terracotta. It could be used to shade the LNB from the sun. As for actually gaining more signal I highly doubt it. No harm in trying though

 

[rodscha]

no,I meant the plastic pot which has an evased shape ,sold with "ricotta" in it

https://www.carrefour.fr/p/ricotta-casa-azzurra-3760056260519

as a plastic device it ll provide shade and rain protection only
my question was,it you cover it in aluminium,make it work as a metal device,could it help?

 

[ozumo]

As long as the LNB is located correctly then I don't think there'd be anything to gain - unless you were trying to block interference from the side reaching the LNB.

 

[Terryl]

You don't want to put anything metal or anything sprayed with a metallic paint out in front of the dishes prime focal area (other then the LNB mounting arm and the LNB itself) this could cause a scattering effect of the signals coming down from the satellite and degrade the performance.

The internal structure of the LNB (after you remove the outer plastic) has a forcing cone built into it, most likely made out of cheap pot aluminium, the LNB is designed to have as small a metal footprint as possible to prevent this.

The only effective way to get more signal to the LNB would be to go with a bigger dish, about every 3 to 4 inches (7.5 to 10 centimetres) increase in the diameter of the dish will get you about 2 to 3 dB of signal improvement.

Here is a site to help with that..... Parabolic Reflector Antenna Gain - everything RF

 

[rodscha]

Thank you Terryl and Ozumo
my reason for asking was
1)I read posts by Algerians in France wanting to catch 7W in Ku-band
using metal based "cones" around the LNB
& claiming this improves reception by 20%
thereby enabling them to receive certain beams from 7W otherwise unreachable for most people living on French mainland.
2)and then ,posts by Indians living in South India claiming the same,
but it was difficult to know whether they wanted Ku-band only (I know they use C-band a lot...)
So,I have to take this as an "urban legend" it seems!

 

[ozumo]

Are there any photos of these 'cones'?

 

[rodscha]

this one (India)

 

[rodscha]

and this one (Algerian in France)

 

[rodscha]

so,a lot of people try to improve reception without going for bigger dishes...and claim it works!

 

[ozumo]

These look more like creating (or modifying) a feed horn for a 0.6 f/d 40mm LNB to make it perform better on a dish which is not 0.6 f/d, in order to make the LNB 'see' more of the dish.

 

[rodscha]

well, the LNB i have must be geared for 80cm the standard size here
& i m using a 120cm... so ,worth a try or just a boondoggle?

 

[ozumo]

Offset dishes of these sizes all tend to be around 0.6 f/d, so LNBs for a 80cm dish will work perfectly fine on a 120cm dish, no need for modification.

 

[rodscha]

i see ,so I already have the perfect equipment!

 

[Analoguesat]

At the end of the day you are not going to lose anything by experimenting. Go for it - hope for the best but dont be disappointed when something doesnt work. You might get lucky and find you get an improvement! Experimenting with weird & wonderful cobbled together equipment is what this hobby is all about

 

[rodscha]

so,I 'm going to start collecting bits and pieces...

 

[Analoguesat]

so,I 'm going to start collecting bits and pieces...

Good - what are you going to lose?? A couple of hours out in the garden on a nice afternoon? Sounds like a good idea to me