True, Bob, but at HF the receiver noise figure is largely irrelevant as
band noise usually totally overwhelms front-end noise. I think that others
have made the point that what the receiver *does* with and to the noise
coming in the front end is key to how well we perceive it to work.
Sounds like you have done some interesting and effective EME work . . .
73/72/oo, George W5YR - the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
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Robert & Linda McGraw K4TAX wrote:
>
> Single conversion receivers have their benefits to offer, so do multiple
> conversion receivers. Then there's the drawbacks that each has to offer.
>
> Simply turning up the gain to max and listening to the roar says nothing
> about quietness. Quietness is measured correctly as nf or noise figure
> stated in dB.
>
> As a clear factual example, I have 2 VHF different preamps and both have
> identical gain. One has a nf of 0.3dB while the other has a nf of 1.0dB.
> Using the same antenna, the same signal source and the same RX path, except
> for the preamp, the preamp with the 0.3 dB nf will allow me to hear signals
> off of the moon while the preamp with a nf of 1.0 dB will not hear the same
> signal. Now we can understand when quiet is quiet.
>
> As another factual example, again using the same antenna configuration,
> preamp, and down converter, I can hear more VHF signals off of the moon with
> the Omni VI+ than with the Paragon. RX bandwidth is the same for both
> receiver paths. Again, and example of when quiet is quiet.
>
> As to the quality to timbre of the noise, well that's subjective in my
> thinking. It's just noise.
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