Locked Re: VS: [WSJTX] Q65 and non-linear RF power amplifiers #Q65

Bill Somerville

Hi Reino, and Steve,

the option to disable waveform ramp up and down is only for the FST4(W) modes, this was due to a particular design of non-linear PA suffering failure when presented by a slowly rising input signal. The feature is FST4(W) specific because the way that waveform is generated is specific to that those modes.

The release note information from WSJT-X v2.3.0 (2021-2-2) for that particular enhancement was:
 - FST4/W: Disable envelope  shaping at start and  end of transmission
   when environment variable FST4_NOSHAPING=1. Works for fst4sim too.

On 07/06/2021 22:24, Reino Talarmo wrote:

Hi Steve,

Non-linear amplifier is fine in principle. Only requirement is that it can deal with the smooth amplitude change during power-up and power-down phases or those are prevented by an extra configuration setting. Unfortunately I don’t remember what it is, an additional configuration file. There was discussion on that issue during 2.4.0 release candidates.

73, Reino OH3mA


Lähettäjä: main@WSJTX.groups.io [mailto:main@WSJTX.groups.io] Puolesta Steve Kavanagh via groups.io
Lähetetty: 07 June 2021 18:34
Vastaanottaja: main@WSJTX.groups.io
Aihe: [WSJTX] Q65 and non-linear RF power amplifiers #Q65


I don't see anything in the Quick Start guide that makes me think there would be a problem with non-linear  (Class C, E, etc.) power amps in Q65.  Am I correct?

Steve VE3SMA

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