[Boatanchors] 813 grid to filament short

[Glen Zook]

Present FCC regulations for power output are now stated in peak output terms.  For SSB that means the highest power peak when modulating.  For data, CW, and RTTY, that means the carrier power.  Unfortunately, for AM, the peak power output  is considerably higher than the carrier output power.  With 100% modulation, the peak power is 4-times the carrier power.  This means that, when 100% AM modulation is present, the maximum carrier power output can only be 375-watts which produces a peak power output of 1500-watts.
If less than 100% modulation is present, then the carrier power can be higher before the maximum of 1500-watts peak output power is reached.  However, unless the operator actually has a wattmeter capable of reading the true peak power output (most amateur radio wattmeters CANNOT read the true peak power because of the latency of the meter movement), or is using another method of reading power output (i.e. an oscilloscope), as to not exceed the power limitations, no more than 375-watts carrier should be run when operating using AM. Glen, K9STH 
 Website: http://k9sth.net
      From: W2HX <w2hx at w2hx.com>
 To: Rob Atkinson <ranchorobbo at gmail.com>; Paul Baldock <paul at paulbaldock.com> 
Cc: Boat Anchors List <boatanchors at mailman.qth.net> 
 Sent: Thursday, October 1, 2015 4:50 AM
 Subject: Re: [Boatanchors] 813 grid to filament short
   
> I wish AM operators would quit expressing power in therms of PEP, a slopbucket term that came about in the 1960s when manufacturers of cheap crappy lightweight sweep tube gear etc. designed for slopbucket, were seeking to bamboozle appliance operators into thinking they had QRO gear ("Up to 2 KW PEP Input!!")  Now, the modern day plastic radio operator pisses and moans about how _heavy_ his dinky table top leenyar is.

>The halfway measurable signal component is the carrier--carrier power tells AM operators all they need to know.

I am far from knowledgable on this subject, but I seem to recall that the FCC's power limits may be specified in PEP (maybe that is only for SSB?) In which case, I would want to know my PEP. Not to know how big my signal was or wasn't, but to compare my emission limits to the regulations. Just my 2c (now worth 1c due to inflation)