This is really nice to see.  Pre-distortion is a common technique outside of ham radio and can hide nonlinearities in modern final amplifiers.  Many of the PAs in small devices are amazingly efficient because they are nonlinear and corrected in this way.  It will be particularly interesting to see what testing reveals about the improvements.

On Nov 27, 2023, at 9:02 AM, Mike Ritz <w7vo@comcast.net> wrote:

Some positive news. (See below.) I’d like to think this is a result of ARRL’s CSI efforts! It does show that manufacturers are taking the effort seriously though,  and that ARRL can make an impact in the technical space as a benefit for members.

Lots of bad clicks and chirpy signals in the CW test last weekend, including one from EU that sounded like an old spark set! 

Hope everybody had a great Thanksgiving. 

73;
Mike
W7VO

Sent from my iPhone, utilizing  a very tiny keyboard fed from very fat fingers

Begin forwarded message:

From: Mike Ritz <w7vo@comcast.net>
Date: November 27, 2023 at 8:40:31 AM PST
To: Alan Rovner <k7ar@comcast.net>
Subject: Re: Icom "Dynamic Predistortion" Changes to IC-7610

Thanks, Al! Another ham sent me a note on this also. Icom is one of the JA  manufacturers involved with the CSI. Ray Novak, N9JA is a committee member. 

I don’t know if this was a direct result of CSI, but I’d like to think so! This is exactly what we were hoping would happen.

73;
Mike
W7VO

Sent from my iPhone, utilizing  a very tiny keyboard fed from very fat fingers

On Nov 27, 2023, at 8:14 AM, Alan Rovner <k7ar@comcast.net> wrote:



Hi Mike I thought you might be interested this news as part of your Clean Signal Initiative.  Icom has released new firmware for the IC-7610 that implements something called dynamic predistortion.  As far as I can tell it generates a cleaner SSB signal when enabled.  I'll include a photo below.  While this is a good thing, it looks like it only works with their upcoming PW2 amplifier.  There is ongoing discussion about whether non-Icom amps will be supported.

Also this only applies to normal SSB voice signals.  CW, RTTY, FT8 or other audio tone modes have no need for this feature.  In order to use predistortion, you have to connect the 7610 to a dummy load and go through a calibration process for each band.

In the photo below the blue graph represents energy without predistortiion and the pink graph shows a cleaner signal with predistortion.  Notice the pink graph has less energy away from the center test tone.

Thought you might be interested, 73,
Al, K7AR


<FLgMmPe5ca0PzGmI.png>

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