Pre-Amps

[LoTech]

I've been reading some conflicting information about pre-amps and Signal/Noise ratios.

Let's say that I have an antenna with a 16 dB gain, and my S/N ratio is -12. Does that mean that the antenna improves the S/N to +4? What about antenna pre-amps? Do they improve S/N ratios or do they multiply the noise as well as the signal?

Thanks,

LoTech

[Terryl]

OMG I'm so sorry we missed this post.

Signal to Noise Ratio, is the ratio of signal over the noise floor in an RF carrier (or other signals) if the RF signal strength was -60 dBm and the noise floor was -80 dBm then the SNR would be 20 dB (no negative SNR’s) if the antenna has a gain of 16 dBi then it would add that to all signals received even the noise floor.

An in-line TV signal amplifier also has a noise floor, (called a Noise Floor Rating) if you’re un-amplified signal has a noise floor of -80 dBm and the amp has a noise floor rating of 8 dB then the over all noise floor will be -72 dBm, it will then raise the RF signal by what ever gain rating in dB.