[AMRadio] Dentron Clipperton on am?..

[Jim Wilhite]

I have an LP 100 and can attest to their ability.  In fact when I 
received it, I was surprised that it showed some transmitters to have 
greater PEP output than people said and low output on peaks on other 
equipment that people hail as good transmitters.

In relation to being  correct about modulation Gary presented a very 
easy to understand explanation.  If you have access to a spectrum 
analyzer you can see the sideband power.  You look at the AM signal and 
modulate it.  You will see the sidebands pop up on either side of the 
carrier.  The carrier will have a sawtooth look to it which is the 
modulation riding on the carrier wave.  When you quit speaking the 
sidebands will disappear like a SSB signal does on a monitor scope.

Some where around here I have a very old book, I can't even remember its 
name, that gives all the analysis and how to calculate what you want 
Kim.  Gary can also do those calculations, but for a weak math person, 
they are difficult to understand so if you want to connect with him I 
suggest you go direct.  Most of us would be lost quickly.

The FCC won't go into this much, in fact they routinely overlook people 
who are running much more than 1500 PEP.  The offenders, if you wish to 
call them that, who do not cause trouble for anyone will be ignored 
besides the FCC is very busy auctioning off the 420-450 Mc part of our 
spectrum, so they don't spend a lot of time with us.  They will make off 
air measurements, if you have a very bad or long series of complaints, 
with equipment that will tell them what you are doing and they don't 
have to be in your yard.

If you are concerned about the power you put into the antenna, then run 
350 watts of carrier with either the requisite 100% either positive or 
negative modulation, or both.  This is an easy solution and doesn't 
require expensive peak reading meters.  Incidentally the LP 100 is a 
very good, well constructed piece of equipment.  It shows my Globe King 
500A puts out about 325 watts of carrier and will modulate that to 1250 
watts PEP occasionally on the right syllable.

Jim/W5JO


----- Original Message ----- 

> Why not just use a good peak reading wattmeter and adjust the output 
> to 1500
> watts PEP, no matter what the carrier power is?  Something like a 
> LP-100A
> would be great for this (wish I owned one!)
>
> However, I think that if you use the 4:1 rule, 160 watts carrier is 
> the most
> you would want to run with 4 X 572B's given their 160 watt plate
> dissipation.  Any more than that with any reasonable transmission time 
> will
> severely stress and shorten the life of the 572B's.  If you really 
> blast
> them with air, you might get away with a little more......
>
> Mike WB0SND
>