RadioBanter - View Single Post - s-meter readings - drake r8 vs.palstar r30cc vs. kenwood r-5000.

BDK · January 5th 07, 06:10 PM posted to rec.radio.shortwave

In article ,
says...
Pete KE9OA wrote:

When you turn up the RF gain control, you don't desense the radio, but you
do give the AGC loop more gain. Maybe this is what you meant.

Wouldn't that make it an IF GAIN control?

A while back I read a review by the ARRL of a transciver and they brought up
an interesting point. Modern receivers have enough gain to "hear" the
normal background noise, so beyond that it really does not matter.

In my environment the noise is so high that almost anything can hear it,
my R-5000 often hears S9 level background noise on 40m and nearby SW
bands. (5-10mHz).

Geoff.

Sometimes, the receiver is picking up it's own CPU hash, or display
hash. The early NRD-525's are somewhat bad on this. Later ones seem to
have partially solved it. Any hobby class radio with a fluorescent
display usually has audible hash someplace in it's tuning range.

My R5000 was hammered by the nearby country station on 1560. If you
couldn't hear images and spurs, there was a lot of hash below 7MHZ when
it was on (days only). It was hugely strong, traveling down the nearby
power lines. On most of my receivers, there would be an S-Meter reading
with no antenna connected at all. If I walked over to the receiver, it
would peg long before I touched the antenna connector. I built a couple
of AMBC killer filters from plans I found in a ham book, and it made a
huge difference. When the station redid it's grounds, after the owners
of neighboring houses started complaining that toasters, TV's, and
anything else that plugged in the wall was playing music at times.

That dropped the signal greatly here, I was able to remove the AM
killers on all my receivers except the R5000, it still had hash that
kept beat with the songs below 7MHZ, and on a few freqs I could hear the
audio in the background on AM stations.

BDK