[UK-CONTEST] Power Limitations

[Paul Selwood]

Currently not having much time for amateur radio it is interesting to review
loads of emails on this reflector covering one subject in the space of a few
minutes, especially this one on changing the sections in VHF contests in
general or just UKAC to relate to ERP rather than purely Power. I leave the
point of measurement  vague on purpose as there had been discussion as to
where the power is measured at the antenna or at the transmitter output. I
stress that I believe that Bob (G8HGN) is only referring contests for VHF
and above.

Bob  (G8HGN) has stated his case well with 100W to dipole and 100W to a
large beam giving wildly different ERP being fired into the ether. His point
is that the sections in a contest should be set up around ERP, and not
merely the transmitter power. It is up to the legislating authority to
decide the sections and limits. They can also come up with guideline figures
for antenna gain thus leaving the vagaries of manufactures' specifications
out of it. Site cannot be taken into account either. Some contest groups do
rather well operating from non-elevated sites.

Ray (G3HRH) raises some valid points regarding measurement gain of antennas,
this also applies to the measurement accuracy of RF Power. Even with the
Bird 43 attached to the end of feeder from a "Typical"  yagi will only  a
+/-10%   measurement uncertainty at best if  you are lucky.  

In these days when the catch phrase is a "level playing field" let's ask the
CC to consider this one. They did in the case of the M5 rule that has
supposed to have levelled the field regarding geographical location. Now
let's go for it in the case of power fired into the ether e.g. ERP.

Paul
G3YDY