[R-390] Preselector

[Bob Camp]

Hi

One place that a pre-amp might help an R-390 is up on 10 meters. The 
radio is plenty sensitive enough on the lower bands but as frequency 
goes up the noise level off a typical antenna goes down. The antenna 
it's self gets smaller and both the man made and natural noise drop off 
some as frequency goes up. You can come up with a sub one db noise 
figure pre amp for just about any band from 1 GHz on down. That has to 
be significantly better than the front end of most HF radios.

A simple way to check if it will help:

Listen to the noise out of the radio as you attach the antenna. If it 
goes up you don't need a pre-amp. Since you have an antenna trimmer 
involved it's a little more complicated than with a rice box, but the 
net result is the same.

	Take Care!

		Bob Camp
		KB8TQ


On Aug 19, 2004, at 5:04 AM, Charles B wrote:

> Hi all,
>
> What happens if you install a small preselector or preamplifier in 
> front of an R-390A?  Does it help or hinder?
>
> Chuck
> ka4prf at us-it.net
>
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