rflinx amps

[bobbyc]

Hi,
I am starting to wonder about these rflinx amps. My first amp I ordered was a stock indoor linear amp; meaning it had a rx of +20dB. The noise floor on this amp in clean environments is -81 on a directional antenna and 10' of lmr400.
My last order of indoor linear amps I ordered with a rx of +16. I figured the noise floor would be better, but it is still -81 on a directional grid and this is a totally different tower.
Do you think I am just used to the -90 noise floors of my YDI mast mounted amps, and these rflinx indoor amps with their 4.5dB noise figure are just more noisy... but it doesn't matter because it's all about SNR?
Bob C

[lonnie]

Two things come into play. SNR is critical but so is the absolute signal level.

If you have a -100 dB noise and -85 dB signal you have 15 dB SNR but you cannot do a reliable 11 mbps since it is below the floor of -83 dB for 11 mbps use (for most cards - newer ones are -85 dB and better).

If you have -80 dB noise and -70 dB signal you only have 10 dB SNR but you are able to do 11 mbps since you are nicely above the -83 dB cutoff.