What is inside FEED Horn

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
Hello,
Yesterday, the weather was not good and monkey has fallen my Dish from Roof to down due to which the Feed horn plastic body was broken totally.
I though The Dish Antenna will not work now, after hours of finding Signal i find Signal from Satellite.
it was working the signal level was not good enough may be due to error on surface rough.
I find there was needle structure pin inside the Feedhorn.
how it is working after brokenor was that plastic body just was upper surface now when there will be rain will it will not work from water.

http://s.hswstatic.com/gif/satellite-tv-7.jpg
 

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
Who knows what damage was done from your description?
Ok.
this was Ku band.
how does the antenna receive the signal from satellite which is very very far in atmosphere.
there is vertical an horizontal polarity in it.
the aluminum frame is very strong of feedhorn.
how it work ?
 

Papabravo

Joined Feb 24, 2006
12,765
All antennas receive weak signals from far away. Small voltages and currents in antennas are detected, amplified, and decoded all the time. A typical transmitter might have 10 watts of power output for example. By the time this signal gets to the receiver it might only have a power level measured in the tens of femtowatts (that is 1e-14 watts). So 15 orders of magnitude attenuation in signal power is not beyond the ability of modern receivers to utilize.
 

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
Hi Ritesh,

The unit you are referring to is a LNB (Low noise block downconverter). It's function is to convert a block of satellite signals in the range of 10 to 12 GHz to a block of intermediate frequencies in the range of 1 to 1.2 GHz to be fed through coaxial cable to a set-top box.

It consists of the following:-

1. Feed horn - a cavity antenna with horizontal and vertical elements
2. Low noise amplifier - for amplifying the satellite signals
3. Local Oscillator & Mixer - to convert the 10 GHz block to 1 GHz
4. Intermediate frequency amplifier - to amplify the 1 GHz output

I am unable to make it simpler than this and do hope you are able to comprehend.

Regards,

Nanda Kumar.
please tell more if you can
 

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
Hi Ritesh,

What's specified is characteristic impedance and not the resistance of a coaxial cable.
I guess it's time you strived to read and learn.
Good luck!
Regards,
Nandu.
Do, you work in Communication Project.
 
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