New Program - OP_ANGLE.exe

This program assists with understanding, choosing and setting the
operating angles of Class-B and Class-C RF power amplifiers.

The operating angle underlies all performance characteristics.

Although RF operating conditions for tubes can be set up using
manufacturers' data sheets, the program refers to use of a tube's
Operating Characteristic Curves.

Download program OP_ANGLE in a few seconds from website below. Not
zipped up. Run immediately. File size = 39 kilobytes.
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Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
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To anyone who may be interested.

In the notes to this new program I omitted to say that the computed
components of plate current constitute the first few significant terms
of a Fourier Series.

There's the DC component, the fundamental frequency component, and the
2nd, 3rd, 4th and 5th harmonic components.

The amplitude of the harmonics decrease as the harmonic order
increases. Amplitudes are the peak sinewave values (not rms).

If the components, including the DC component, are added together
taking into account their signs, then their sum is very nearly equal
to the computed peak instantaneous plate current. Which has been
adjusted to equal the actual value which flows in the tube.

If the Fourier Series had been extended to even higher harmonics then
the sum of the series would have converged to the peak instantaneous
value of plate current exactly.

This is a check on the accuracy of the Fourier Analysis performed by
the program. There's ample oportunity for bugs.

If an amplifier is used as a frequency multiplier then power can be
extracted from the plate by an LC circuit tuned to the required
harmonic.

The correct plate load impedance is the required peak RF volts across
it divided by the peak amplitude of the plate current component.
There is NOT a conjugate match. The internal resistance of PA's is
NOT 50 ohms as is commonly believed. With pentodes, beam tetrodes and
transistors (transistors have operating angles) it is often much
higher.

There, I've said it again!
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Reg, G4FGQ.

Program OP_ANGLE

The Fourier Analysis of plate current has now been extended from the
5th up to the 7th harmonic. Otherwise the program has not been changed
except for the issue date. If you are still interested, download the
new version and use it to overwrite the first.

It seems that for almost exact agreement between peak plate current
and the sum of the harmonic components it is necessary to extend the
analysis up to around the 20th harmonic. There's not enough room on
the screen to display results.
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.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........