[AMPS] power v. QRM

[Peter Chadwick]

Another point is the acceptable signal to interference (S/I) ratio needed.
Some of the 80m gang over here complain even if the S/I is 30dB or more -
which is generally less than the distortion in their receiver. On FM capture
ratio allows much lower S/I ratios. When you're hitting a pile up on 20, you
can be running with a S/I of 4 or 5 dB - or worse.  So you cannot
necessarily cause QRM with greater power.

You must also remember something which I find very hard to get over to
people at ITU and CEPT viz. you can only cause interference to a service
that is there. So if nobody is using the channel, you can't interfere  -
with anybody. Thus using 1500 watts may well extend the effective
sterilisation zone produced by a station, but this may not matter if there
is little spectrum pressure at that time.

Of course, if you happen to be on somebodie's 'frequency' which they've used
every day for x years, any emissions will be regarded as deliberate QRM!

73

Peter G3RZP

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