cmor wrote:

The signal itself is coming from an avalanche transceiver ( a pulse at
457khz every second or so) which has a relatively small antenna and
the signal attenuates quickly , most receivers only have about a 25m
straight line range and I'm trying to improve on that. I thought the
small range was due to the weakness of the signal, I'm a bit clueless
as to how much of the problem would be from radiant noise, although
these posts are starting to give me some insight. Thanks for the help
thus far.

-Chris

As Tom says, once your antenna is good enough to make atmospheric noise
louder than receiver noise, you can't do anything to further improve the
S/N ratio unless you can null out some noise from a single direction (or
opposite directions). And it doesn't take much of an antenna or receiver
to do that at this frequency.

The only way to improve range, then, is to make the transmitted signal
stronger with respect to the atmospheric noise. To do that, you'll need
to increase the strength of the transmitted signal by increasing
transmit power or improving the efficiency of the transmitter antenna.

Roy Lewallen, W7EL