[Amps] SWR and amplifiers

Paul Christensen w9ac at arrl.net
Thu May 25 15:57:27 EDT 2017


>"If the output stage is broad-band tuned and biased in Class A, it will absorb some or all of the reflected wave which may increase heat losses. In this case, the reflected wave is not re-reflected and will not show up as an increase of the forward reading."

Karl and all...

Does anyone know of a computation that predicts the level of power absorption in an amplifier (or classic generator) based on operating class and reflection coefficient?  This is an area of transmission line mechanics that is universally treated as a footnote rather than a detailed explanation with mathematics -- possibly because it's in a gray area at the intersection of amplifier and transmission line theory.

Some of you may recall an ongoing debate on a related matter between Walt Maxwell and Warren Bruene where each intensely defended their position as to whether a conjugate match existed in a power amplifier when tuned for maximum available output level.  Class of amplification entered into that debate and was acknowledged by both parties, as I recall.  I am more interested in getting to a number that shows power loss due only to reflected wave absorption in the exact situation that Karl describes above.

Paul, W9AC    




---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus



More information about the Amps mailing list