What does RF, IF, and LO mean on an LNB?

[TGBlackheart]

Just bought an LNB and it has the following written on it:

RF: 11.7 - 12.5 GHz
IF: 950 - 1750 MHz
LO: 10.75 GHz

Looks like input and output frequency for the 1st two frequency ranges.

But I was wondering what RF, IF, and LO exactly are abbreviations of?

Thanks in advance

 

[Mr Tony]

LO is local oscillating frequency (what you set the receiver to)
RF must mean radi frequency
no clue on IF

All I know is if you take the RF frequncy and subract the LNB LO thats the IF frequency

example=12000 RF freq - 10750 LO = 1250 IF frequency
Some receivers only will allow you input IF frequency (these are usually commercial recievers)

 

[TiminMb]

IF is intermediate frequency. When you mix two signals of different frequency together, you get two new signals, the sum and the difference. This is exploited in RF (radio frequency) circuits to create a lower frequency signal which is easier to work with. So in come the satellite signal at 12000 mhz, the local oscillator beats out a constant 10750 mhz. This generates an intermediate frequency of 1250, which is more easily conducted down the coax to the receiver for demodulation. The receiver probably also contains one or more similar stages which convert the signal into a lower frequency once again, for eventual processing for signal.

 

[TiminMb]

Iceberg, it might be helpfull to have a glossary of commonly used FTA terms, such as LNB, TP, PIDS, etc. I know I used to struggle to keep up with you guys and all the abbreviations, and I still end up wondering what you are talking about at times.

 

[bill190]

In practical terms...

"RF" is the frequency range that LNB can receive from a satellite. This would differ between a C-Band LNB, a Ku band standard LNB, and a Ku band universal LNB.

"IF" is the frequency range your receiver would use. If you have "blind search" on your receiver, this is the frequency range you would tell your receiver to search (for the particular LNB). This also would differ between a C-Band LNB, a Ku band standard LNB, and a Ku band universal LNB.

L.O. is the local oscillating frequency of the LNB. You specify this in your receiver set-up when you are using this particular LNB. This also differs between different types of LNB's.