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[TenTec] What is "quiet"?

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Subject: [TenTec] What is "quiet"?
From: RMcGraw@Blomand.Net (Robert & Linda McGraw K4TAX)
Date: Tue, 02 Apr 2002 21:22:39 -0600
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.

73
Bob K4TAX




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