[UK-CONTEST] pile ups

[Bob Henderson]

Colin, J38CW wrote:

"Signals when in the pileup seemed to be weak and sucked into each other and
although there maybe hundreds calling at anyone time (and there was), once
you could pull out a callsign the signal would be 5/9 or stronger, any
explanations?"

Signal to noise ratio or more accurately signal to QRM ratio.  With a dozen
S9 signals calling together you might have a signal to QRM ratio of only a
couple of dB and an equivalent received signal dynamic range.  When one of
those signals stands alone at S9 with a background noise level of say S3 you
night suddenly have S/N of close to 40dB and similar received signal dynamic
range.  The dynamic range of the received signal is a significant
contributor to the perception of loudness.

73 Bob, 5B4AGN