[AMRadio] AM and power

[Brett Gazdzinski]

I tried the amplifier thing and do not like it at all.
I have a flex 3000, 100 watt rig, so about 22 watts of carrier and 100 watts 
pep output.
I built a homebrew grounded grid amp using four 813 tubes and ran it off the 
big rig modulator power supply, say 3000 volts.
Four 813 tubes have 500 watts plate dissipation so that gets me about 100 
watts of carrier and plenty of PEP if I want as you can adjust that on the 
flex stuff.

Hard to tune up, got to play with the drive levels, tune and load the amp, 
back things down, pain in the butt.
Then the thing was giving off huge amounts of heat for 100 watts of carrier. 
Just stupid.

Then I have a pair of 813's in the big rig, runs cool at 600+ watts of 
carrier output, dip and load to 400 ma and away you go. I have no problem 
getting 2500 watts pep out of it, up to 3000 watts pep or more if I pushed 
it.

Maybe life would be good with one of those big solid state amps, but its 
going to be about 75 or 100 watts out, same as a G76 or dx-100. Its also the 
duty cycle, the 813 amplifier would put out 2kw of ssb easy and would run 
cool doing so.

A single 813 will do close to the legal limit on AM, at least 300 watts 
carrier and run cool doing it.
I get 300 watts out of my 3x4d32 rig, that is three 4d32 tubes, they used to 
be $20.00 each so I have a bunch.

A pair of 812a's or 811a's will do 300 watts of carrier, and a pair as 
modulators is easy, and more then enough audio power.

The guys who seem to be real wide on 80 meters seem to be running big class 
E rigs with lots of audio on the carrier, and they limit the audio to 10 
KHz. They KNOW they are 25 KHz wide and do not care, they tell me AM is 
supposed to be wide. Well, I hear great sounding people on the air that are 
only 7 or 10 KHz wide, and even some that have most of the power in 5 KHz.
Its an ego thing, or an insecure personality making up for limited body 
parts maybe, I don't know.
I got no problem sounding as good as you want (wide) on an open band, but at 
prime time, taking out the entire AM window (with 2 other qso's on it) seems 
kind of rude to me.
That is the downside of the sdr gear, you can see just how rude someone is!

Brett
N2DTS






>
> Some of the folks I listen to on 80/40 meters, have the "attitude"
> (My version of AM is the only one that counts!) When they are
> called to task for being too wide or generating spurs up and down
> the band, they say the "finder of the offense" has a cheap receiver
> poor antenna, or No "YA M" skills. Rubbish, if it isn't working
> properly, correct it, don't start ragging on the guy who caught your
> error! The error remains until you fix it, simple as that.
>
> The Clique mentality is what causes most of the problems,
> as in "Interlopers Need NOT Apply", makes no sense and wastes
> others time, yet another good reason to shut down and go watch
> TV!
> FWIW
> Jim WB2FCN
> "Real radios have tubes, and weight 600+ pounds"