Steve Thompson wrote:
>
> On a 144MHz contest
> station, set up on a site with sea takeoff from E to SW, swapping 2x9 yagi
> for a 50R resistor does not change the noise we hear,
This implies that what Tom called the average gain of the antenna is not great
enough to override the rx generated noise. A low-noise preamp would boost both
signal and noise from the antenna and solve this problem.
> swapping 50R for 4x19
> yagi results in a clear increase in noise, I estimate about 3dB.
This antenna has more gain, so you are now hearing atmospheric noise, as you
should.
> The earlier reasoning implies that we should get the same noise from both
> antennas, but we don't. What are we hearing?
In my earlier comment, I assumed (and didn't say!) that there was enough output
from the antenna to override internal rx noise.
73,
Vic, K2VCO
Fresno CA
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