[AMRadio] AM Amps

Brett gazdzinski Brett.gazdzinski at mci.com
Tue Jan 11 15:23:50 EST 2005

When I run the pair of 813 rig, its doing 600 watts carrier out,
and I limit my negative modulation to about 90%

I used to run it to over 2000 watts pep, 2500 judging by how
hard the watt meter pinned.
That was when I used negative cycle loading, which did not work
fast enough to prevent splatter as I found out.

Now days I think the pep gets up to about 1700.
My voice does not show a lot of asymmetrical waveform on any transmitter,
although it used to go higher before I got the berringer and new microphone.

Figuring in the old uncalibrated swan wattmeter, some swr, maybe I am even
Since the FCC changed it to a pep reading, all you got to do is get a stingy
pep meter as far as I figure.

Maybe run the carrier to 1500 watts and have a broken pep section
on the watt meter?

Could anyone tell the difference between 1500 watts pep, and 2000 watts pep
at some distant location?
My 80 meter antenna is somewhat crappy anyway, and someone running
1000 watts pep with a better antenna could sound a lot louder than me...

Maybe it should be effective radiated power, in that case I am
way legal.



-----Original Message-----
From: amradio-bounces at mailman.qth.net
[mailto:amradio-bounces at mailman.qth.net] On Behalf Of Robert M. Bratcher Jr.
Sent: Tuesday, January 11, 2005 11:43 AM
To: Discussion of AM Radio
Subject: Re: [AMRadio] AM Amps

At 04:31 AM 1/11/2005, you wrote:
>73s to all,
>regarding Dick's problem i'd try to match 1st the Ranger's output pwr with
>the needed input pwr of one of the amps.The choice of the amp depends on
>output pwr someone wants to "push on the air".Saw a Ranger there in Ebay
>think it's using something like 6L6s or anyway not high power output tubes.
>"Playing"with the outputs B+,or grid HV or grid pollution resistance,in
>order to reduce or increase the output pwr and match it with amp's input
>it's easy.Resistances for the B+ and grid HV and a meter to measure.The
>greatest the 2nd grid resistance is in value the worst.It's "pushing hard
>limits" the tube depending on the B+ and grid voltages also.
>Hope it helps,
>Chris SV1DAF.

If I wanted more than 100w of AM (out of my Collins 23V-3) then I'd use it 
for carrier only then plate modulate an amplifier with a modulation 
transformer (if I could find one) plus a speech amp. Then I'd run the 
maximum legal AM power of 375 watts.

But then I run AM on the KW-1 (pure DSB AM) & sometimes the KWS-1 (which 
does carrier plus one sideband) at the 375w limit. I'd prefer to do AM at a 
kilowatt but thats not legal anymore.

I wonder how many AM'ers run more than the legal 375 watts? I've thought 
about it... 

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