"998cc" wrote in
:

....
floor of the rig. I did try chercking the receiver noise with a
Microlab dummy load installed at the radio then with the antenna
conneted. Yes, there is more noise with the antenna connected. What

The higher the ratio of noise from the antenna to noise from the dummy
load, the less likely you are to get much benefit from a better receiver.

You need this ratio which tells you the ambient noise (albeit with IMD
noise rolled in) to predict how much a LNA or better receiver will
improved things.

Of course, by 'improve' I mean better S/N ratio, not simply higher S
meter deflection.

Alternatively, you suck it and see.

is interesting is that with the dummy load connected, the noise was
just higher than wit the ope SO-239 at the radio.

I assume that was to say "with the open SO-239".

I don't really know what you can conclude, because you don't know enough
about the radio when the input jack is o/c.

Owen