David,
Reducing the audio drive level "well below ALC indication" is not a good
idea because the KX3 will 'power hunt'.
You should have at least 4 bars indicated on the ALC meter with the 5th
bar flickering.
ALC action is indicated by the 5th bar and above. Below that the "ALC"
meter is more or less like a VU meter to allow you to adjust the audio
drive.
73,
Don W3FPR
On 1/12/2016 4:26 PM, David Anderson wrote:
I just finished playing the two test files that the author supplied, through
the sound card to the KX3 and used the Data A input so that there was no
compression or TX equalisation taking effect. I had the scope connected to a
sampler on a dummy load and the KX3 set to 14.3 MHz at 3 watts PEP.
The RF power levelling in the KX3 does a very good job. Reducing the drive
level of the audio well below ALC indication made almost no difference as the
KX3 just went ahead and levelled the power again to 3 watts PEP ...
I captured the peak output on the digital sampling scope for both the
conventional and CESSB signal from the KX3 RF output and here are links to the
scope screen shots.
First the CESSB
https://www.dropbox.com/s/0kjrvzispyb45jy/CESSB%20ESSB%204KHz.BMP?dl=0
The conventional SSB
https://www.dropbox.com/s/m4mmlwkcb77540c/conventional%20ESSB%204Khz.BMP?dl=0
Not a lot of difference, certainly not as much as there is if you compare the
audio files going into the rig.
73 from David GM4JJJ
On 10 Jan 2016, at 18:36, Michael Walker <[email protected]> wrote:
Hi David
I doubt you ever will. If I remember correctly, what the CESSB does is
correctly clamp the gain while ensuring you continue to get full power.
The micro second you go over 100%, the radio starts to clamp RF out and in
fact reduces it considerably. You would only be able to tell by watching
your RF envelope in a scope.
This is all off the top of my head, but that is what I remember. I'll have
to read the paper on it again.
There are likely others that know more about it than I do.
Mike
On Sun, Jan 10, 2016 at 11:44 AM, David Anderson <[email protected]> wrote:
Mike,
I don't know why but I kept using ECSSB when I meant CESSB obviously,
sorry for any confusion!
Although the Elecraft power levelling is excellent, and I have not ever
had bad reports of audio quality or splatter with my KX3 with the processor
on or off, it certainly would be nice to be able to increase the talk power
further as CESSB promises.
73 from David GM4JJJ
On 10 Jan 2016, at 16:04, Michael Walker <[email protected]> wrote:
This was presented at Dayton this year. If memory serves me correctly,
it
was installed in SmartSDR 1.2 back in March of 2015.
http://www.flex-radio.nl/flex-6000-serie/the-flex-insider/
It is very interesting just how big the impact of overshooting has on
killing your RF output.
This is one of those ... less is more .. situations.
Mike va3mw
On Sun, Jan 10, 2016 at 7:53 AM, NC3Z Gary <[email protected]> wrote:
Thanks for the link, my ARRL magazines take more time to get to me now
that I am out in the boon-docks. The new QEX article is a good read, and
with flex incorporating CESSB we can hope that maybe Elecraft can
incorporated it into at least the KX3.
Gary Mitchelson
NC3Z/4 Pamlico County, NC FM15
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