Frequency between the LNB and Receiver

[intrac]

I'm curious to know what the band of frequencies are between the LNB and the receiver input.

Lyngsat gives some frequencies, but I believe this is the the input to the LNB.

The LNB has its' own oscillator, so I think the frequency output may be different to the receiver - somewhere in the range of 900 to 1500 MHz.

Why then would RG6 swept to 3MHz be so critical?

 

[Jared Twomey]

900-2150 i believe... i could be a little off on those numbers

 

[harshness]

The 950-1450MHz numbers come from legacy equipment that can only put the even or odd transponders on the cable at any one time. Band stacking (both even and odd transponders) demands that you have at least double the bandwidth available.

The range of frequencies is about 975MHz to 2.15GHz (250MHz to 2.5GHz for DIRECTV).

The nature of ranges dictates that the performance falls off (usually by 3dB) on the ends, so to ensure flat performance, it is often necessary to spec a cable that goes wider than the desired band.

 

[boba]

The old standard downconverted freq was 950-1450 mhz but both DISH and D* have come up with band stacked systems. DISH Pro uses 950-2050. D* I think was 250-1450 but I would have to research that.

 

[intrac]

So if somebody were using legacy equipment, the upper end would be around 1500 MHz, but using the new DP LNBs, the upper end is around 2500 MHz.

In looking at cable, it appears that cable swept to a least 3MHz has a lower loss at 2Mhz than cable swept only to 1.5 or 2 MHz.

 

[Smith P.]

The band have own designation: L-Band.

Dish using: 950-1450 and 1650-2150 MHz;
DTV: 250-750, 950-1450 and 1650-2150 MHz.

 

[intrac]

Is this right then that if using legacy LNBs, the frequency range would only be 950-1450 MHz and legacy LNBs don't do band stacking.

 

[Pepper]

that is correct.

 

[harshness]

Legacy LNBs required something like an SW21 to stack the evens and odds together.

 

[intrac]

You are right -- and the bands are still in the 950-1450 MHz range.

 

[Smith P.]

Wrong !

Legacy LNBs required something like an SW21 to stack the evens and odds together.

Incorrect!

Those legacy SWITCHes are switching L or R polarity signals in same L-band range 950...1450 MHz.

 

[Jared Twomey]

Incorrect!

Those legacy SWITCHes are switching L or R polarity signals in same L-band range 950...1450 MHz.

:up