O
>Tom, I hope you meant 20 db gain. I'm not sure a preamp with a noise
>figure
>of 20 DB (at 1.8 mhz) is wise. What is the noise figure on 160 for the
>typical receiver? Probably less than that. Ambient noise is certainly
>predominating in most cases.
>
>73, Dave -
W5UN w5un@wt.net
Dave..the best preamp has 0 dB of gain on 160...just a LC tuneabler
preselector if you are using a good Beverage.
The ambient NF on 160 after dark can/is in the 25-35 DB range according
to everything I've ever read. That is why that cranking in 10-20dB of
front end attenuation often helps during high QRN condx. The RX
performance does not degrade but the reduction in IF and filter blasting
from static crashes improves the SNR quite a bit. The average ricebox has
a 10-15dB NF on 160M anyway.
73 Carl KM1H
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