[Elecraft] Pwr<>Antenna

[Ron D'Eau Claire]

Paul wrote:

I may be missing something but I had 2 homebrew amps running 813s, another 
one running 4-572B's by Dentron and recently since 1997 had a Ameritron 
AL80B till 2004. I sold all amps because I am satisfied with 100 watts from 
the Icom 706 and my QRP rigs. BUT, my point is I never noticed any increase 
in my utility bills!

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The "big current" drain only happens when the key is down or on
instantaneous voice peaks. 

Hopefully, no one puts a brick on their key at a kilowatt output! 

Electric rates vary widely around the country too. Here our little local
Utility charges a bit under 3 cents/kilowatt hour (our power comes from the
Columbia River hydroelectric dams) and other places have quoted over 20
cents/kilowatt hour. 

It's tempting to run a kilowatt to a poor antenna in an attempted to "get
out" better, but keep in mind that short antennas, such as one tends to have
in cramped quarters, produce HUGE RF voltages, even at low power levels. 

Back in the 1950's some famous (or infamous) mobilers experimented with
kilowatt mobile rigs.  Keep in mind this was in the days of vacuum tubes.
Such setups often used several generators attached to the automobile engine
and a whole back seat area of the car filled with equipment (and the stories
of stalling the engine by hitting the transmit button were true!). One of
their frequent problems was that a huge corona discharge would often leap
off of the tip of the antenna, producing huge distortion on the signal. You
would never want to see that inside of an apartment or your attic! 

Another issue is the electromagnetic field itself. There are valid concerns
with the effects on human health of strong electromagnetic fields, including
the possibility of causing cancer. The ARRL has a lot of good data on this
subject and it's covered in all recent ARRL Handbooks. 

In any case, the fields produced by QRO operation with indoor/temporary
antennas are likely to cause very serious problems with all other appliances
including lights, radios, televisions (even battery powered portables),
microwaves, computers - you name it. At QRO levels, if a device runs off of
electricity it's likely to be severely affected by a nearby antenna! 


Ron AC7AC