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Re: [CQ-Contest] Cheating - Big Amps

To: <e73m@e73m.com>
Subject: Re: [CQ-Contest] Cheating - Big Amps
From: "Tom W8JI" <w8ji@w8ji.com>
Reply-to: Tom W8JI <w8ji@w8ji.com>
Date: Tue, 6 Sep 2011 17:08:47 -0400
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
Hi Danny,

The biggest problem we have is people hammering their already marginally 
clean radios and amplifiers trying to get a little extra power. That is just 
stupid CB operating, let's not encourage it. I hope all those people, 
instead of making a 100 watt radio run 130 watts to make a small amplifier 
big, buy 5 kW amplifiers and just turn their radios back to normal.

As for the manual, a manual will say anything the writer wants it to say. It 
does not mean it is correct. It also does not mean it is normal behavior for 
other amplifiers.

For the manual to be true, efficiency would have to decrease much faster 
than plate input power decreases. That also would mean on SSB, with lower 
average voice power, the amplifier would become hotter with quiet steady 
voices than full peak power and speech processing. This does not mean all 
normal amplifiers work that way. Normal AB amplifiers near full power reduce 
efficiency nearly in proportion to power input reduction. They do not reduce 
efficiency much faster than input power is reduced.

All those who have amplifiers that really get hotter as drive power is 
reduced, I have bad news. Your amplifier needs work. It has a grid bias, 
conduction angle, or voltage regulation problem.

I can explain why that is true, but this is not the correct forum. This is a 
forum for people to insult each other between contests, not to help each 
other.   :-)

If someone is really running large amplifiers for conservative operation, 
then we should all be thanking him. The people we should not be happy with 
is the person who wants 1 kW but only has equipment for 750 watts.

I would rather have a 5 kW amplifier running 2500 watts next to me on any 
band than a 100 watt radio trying to run 150 watts because some cheap Ham 
wants every possible watt of power. Maybe he runs the radio at 150 watts so 
the 100 watt radio runs cooler and cleaner than a 200 watt radio at 150 
watts?   :-)

73 Tom 

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