receive test performed with a broadband amp
- I was just playing with my RXTX 80/40 softrock on a poor, indoor
antenna, with the built in soundcard on my dell inspiron 2200 laptop.
I had an HP461A broadband amplifier ( 1KHz to 150 MHz) and put it in
series with the antenna input.
When I switch the amp in at 40 db, the 'center peak' went away
entirely. It was swamped in the noise signals and there is actually a
small 'dip' there.
With the amp at 20 db, the center peak is about 10 db above the noise.
Without the amp, the center peak is 'wide' and about 30 db above the
So, a bit of RF amplification ahead of the softrock, even though it
has no real benefit as to making weak signals stronger, can cover up
the audio card noise with atmospheric noise...which is useful.
Of course, with a better sound card, with less noise, there is less
benefit from putting gain at the antenna.