Geoff Edmonson wrote:
I spewed my drink all over the monitor when on Friday 19 December 2003 01:41,
[EMAIL PROTECTED] said (and I am -not- making this up!)::
In a message dated 12/18/03 10:41:35 PM, [EMAIL PROTECTED] writes:
It has been my experience that of everything is workig right, and the
output circuit is efficiently designed, the maximum reliable power
output from a linear amp running standard AM is about equal to half
the total rated plate dissipation of the tube(s). i.e. for a pair of
6146's, 20-25W carrir, 80-100W PEP.
Good rule of thumb. I've operated my home brew 3-1000Z linear on legal
max AM. The tube is dissapating about 800 watts under carrier only condx
in this mode and the plate runs a nice bright yellow-orange!
Dennis. what are you calling "legal max AM"?
The only legalities we have anymore, is 1500w PEP output.
Depending on the natural asymetricalness of your voice, will depend on how
much PEP output you have (which is quite difficult, at best, to measure).
The Rule of thumb is, if you modulate a carrier to 100% with a sinewave, the
Peak Envelope Power Output is 1,500 watts. That would the carrier power(x4).
or 375w of carrier output, or (roughly) 500w DC input to the final.
The problem with that is, we don't speak in sine-waves ;-)
For more information on figuring PEP power, see
http://www.qsl.net/wa5bxo/amplitude-modulation-and pep.htm
For a great write up on asymetrical audio, see
http://www.qsl.net/wa5bxo/asyam/aam3.html
Dig around the website. Be careful, though - you might learn something ;-)
Happy Holidays
73 = Best Regards,
-Geoff/W5OMR
Geoff,
What's wrong with what he said? He is talking about LINEAR operation not
a plate modulated final. His figures are correct for "rule of thumb".
Remember 33% efficiency for the carrier in linear AM operation.
73
Gary K4FMX
