[AMRadio] Power Levels

[Donald Chester]

There is absolutely no mention of 375 watts anywhere in Part 97 of the 
rules.  Furthermore, I have never seen two "amateur radio quality" power 
meters that give the same power readings for a given transmitter power 
level.  Even the "professional" quality power meters assume a 50-ohm or 
other precisely-known, purely resistive, nonreactive load, with no reflected 
power. This is not a problem with broadcast and other commercial 
installations where the transmitter operates on a fixed frequency to one 
specific antenna, but, except for well calibrated dummy loads, extremely 
difficult to achieve with typical amateur radio antennas, where the transmit 
frequency varies widely, and numerous often hastily constructed and 
installed antennas are used. This is not to mention antenna tuner and 
feedline losses, and modulation waveform.  Realistic measurement of 
instantaneous peak output power (rf power input to the radiating antenna) 
for amateur installations is so elusive that at best it is a ballpark 
estimate.

The difference in power output wouldn't amount to a hill of beans whether 
your T-368 were precisely tuned or not, in terms of what is heard at the 
other end.  I wouldn't lose any sleep over a few occasional voice peaks.  
There is a loophole in Part 97 that makes the rule even more vague and 
confusing:  p.e.p. is defined as "under normal conditions".

Just use common sense.  You know perfectly well it would be illegal to put a 
5 or 10 kw broadcast transmitter on the air at full power, but a T-368 or 
BC-610, or even a KW-1 would operate somewhere within the ballpark of the 
"legal limit". Do you split hairs this much over speed limits while driving, 
worrying whether you are actually going 54 mph or 56 when the speed limit is 
55?  How many times have you heard of hams being cited for overpower since 
the new rules took effect over 12 years ago (despite all SSB operators who 
brag over the air about their "3-holers" and pairs of 3X1500's)?  The people 
at the FCC are the ones who created the confusion with the power rule.  
Amateurs did not petition for this change.  Don't let it spoil your fun.

Don K4KYV

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