In article , "Dan Finn"
writes:

"Len Over 21" wrote in message
...

On most modern HF transceivers, the 3rd harmonic has the strongest
content of RF. The 3rd harmonic of 3.5 to 4.0 MHz is 10.5 to 12 MHz
and there aren't many "ham listening frequencies" there, are there?

For most modulated sine waves, the 3rd harmonic is usually the strongest
*harmonic* although it depends upon several factors. Generally, the odd
harmonic components add and the negative components subtract with modulated
sine waves.

Oh my, such interesting math (which wasn't shown)...:-)

That isn't quite the case in any real world OR the theoretical world.

First of all, in the real world, you must be presuming some absolute
zero phase shift for each harmonic to make your statement. That just
doesn't exist.

I can do the numbers on the series formulas for AM, FM, or PM no
problem but so few in here can follow even the beginnings of such that
I won't care to put it in public view...:-)

Having said that, most modern rigs that produce FCC quality
signals will filter such harmonics several 10's of dB rendering reception
almost impossible except in the near field.

Really?!? They work PERFECTLY ACCORDING TO SPECIFICATIONS
ALL THE TIME?!?!?!

That's not a realistic view, but feel free to indulge if you've laid out a
big
plastic for a couple kilodollars worth of transceiver. :-)

That old standby tube output matching circuit, the "Pi-network" is only
good for about 18 db per octave attenuation above cutoff frequency. Not
all modern transceivers have such "lowpass filters" since they rely on
Class B or AB linear amplifiers with rather broadband transformers
matching PA to load.

A typical 100 W RF transceiver has a fundamental power output of +50
dbm. If there is as much as "60 db harmonic attenuation" in it, the
harmonics can be -10 dbm into the load. That's 100 microWatts and
DOES radiate and rather beyond the Near Field...the level is a lot higher
than most "40 db over S9" signals (depending on who assigned what
levels to a local transceiver S meter).

I thought I needed to correct
this BS, that emanates from someone who claims to understand modern amateur
technology theory.

Feel free to do your numbers in public, senior.

Call it all the "BS" you want to. When you can actually MAKE a linear
(of any class) go as low as 40 db down on total harmonic output, I'll be
giving you a round of applause.

Hams transmitting signals of any significance on 12MHz
will not be hams for long.

Oh? Were there any recent NALs published at the FCC or ARRL sites
on such things? Let us know, please, I've not seen any of those
concerning out-of-ham-band interference due to harmonic generation.

LHA