Satellite Communications/LNB LO

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Question
Dear sir,
my question is we have installed a satellite dish let say Asia sat 5,100 degree east. and in its channels list some channels are horizontal and some are vertical. I tuned a channel with polarity H and frequency 3960 but I didn't receive any channel. Then I add 600 value in LNB LO then LNB LO becomes 5750 instead of 5150 then I receive the same channel. or with same LO but minus 600 in frequency value (3360 instead of 3960). Plz make me understand how its possible? Is this the difference between horizontal and vertical polarization?

Answer
Mr Abdul,
You first look at the definition of Polarisation. This gets specified as either Horizontal or Vetical. Any D/L frequency can be V or H. So there is no relationship between Lo tuning frequency and Polarisation. If you have kept the feed to receive H, it can receive all specified H channel frequencies and similarly for V also. You always orient the feed for H or V and NOT tune to H or V. Also look at Uplink and Downlink frequency charts in C- Band Satellites. You will understand the method of Receiving the correct channels. Consult your Manual for exact way of receiving the channels.
Cheers/GTRao

Satellite Communications

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TIRUMALA RAO G

Expertise

Satellite Communications Applications, Link Calculations, Teleports, Earth Stations,VSAT, Tracking, Mobile Communications, Next Generation Networks.

Experience

40 Years. Indian Space Research Organisation, PANAMSAT, Satellite Based VSAT Networks, IP Networks.

Organizations
ISRO, PANAMSAT, Engineering Institution for Higher Education (GVP College of Engineering), Consultancy.

Education/Credentials
Graduate in Electronics and Communication Engineering with Distinction. Guiding scholars for their Doctoral thesis in related areas in Academics.

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