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I have to agree with Mike on this one. If you are showing any
alc your are over-driving and putting out a crappy signal. I see
it all the time. These poorly setup stations with an extra wide
signal that no one can operate next to because they are causing
distortion that is outside the bandwidth for ft8. I run an OLD
radio a Kenwood ts-520 with a home made interface. I can run my
rig all the way up to about 120 watts before showing ANY alc and
then I back it down to show NONE. This is not SSB Phone so ignore
everything about alc when it come to ssb phone operation that you
have learned. If you are showing alc your putting out a crappy
signal and you should stop. If you don't have a clue what you are
doing stop transmitting and find someone to help you that knows
something about digital operations. Those who are running crappy
signals are just ruining operations for everyone else.
Regards,
Steven Greer
K3SRG
OMISS #10630
OMISS 80M Band Coordinator
NOTE: This e-mail was made with 100% recycled electrons. No
electrons were harmed,
No trees were destroyed, No animals were killed,
and No political correctness was observed in making or sending
this message.
On 6/13/19 12:39 PM, Black Michael via
wsjt-devel wrote:
Nobody is saying that ALC is the cause of the problem.
There's lots of things feed into the ALC.
It's simply an indication that SOMETHING is over driving
the rig when the ALC indicates more then 0dB of
attenuation.
I think you'll find if you reduce the USB Mod Level
you'll find the ALC can be reduced to 0 on the scale and
still get 90W out if WSJT-X is at full power and you have
0dB on the Playback device.
I've done that on about 5 IC-7300's and they all end up
at either 6 or 7 on the USB Mod Level.
de Mike W9MDB
For what it's worth, I have a different
view of how ALC works.
First of all, I don't think that properly
implemented ALC causes more than a trivial amount of
distortion in the signal.
Audio processors in studio sound boards and in
commercial radio stations use it routinely. It has
the benefit of
stabilizing the audio level. The FT8 signal has
constant amplitude so ALC does not have to work hard
at all.
It just sits there maintaining constant
transmitter output power.
I checked to see what the ALC was doing in my
ICOM IC-7300 and saw that it was about 55%, which is
perhaps
a little too high. So I reduced the Speakers
(USB Audio CODEC) from 20% to 15% and the ALC
dropped to 45%.
I am using the built in soundcard in the IC-7300.
I am not having any problems in making contacts and
I think
that my signal is clean. To prove otherwise would
require using laboratory instruments to test the
signal...
73, Roy, W7IDM
I have used the following method
regardless of radio used...
Use an external power meter (after the
transmitter).
Adjust audio gain/drive until the point where
power meter stops rising. At this point, the
radios ALC meter will start to show some
deflection. Back the audio back slightly. The
power output will stay about the same and ALC
will be "0" on the radio's meter.
Make contacts :)
On Thu, Jun 13, 2019 at 7:42 AM Black
Michael via wsjt-devel < [email protected]>
wrote:
Only when the manual is correct.
Most are wholly inadequate in this
respect. Mainly due to not addressing
digital modes at all. Even Kenwood's
own TS-890S multi-lingual manual doesn't
mention this.
I just worked with a user yesterday
with in IC-7000 and RigBlaster Advantage
in the ACC socket and had to have the
MIC level set at 1 and we could crank up
the RigBlaster TX to get 90W without any
ALC action on the rig. If we cranked up
the MIC gain and turned down the
RigBlaster TX we could get ALC action at
10W (note that the rig was always set at
100W).
Any manual that talks about SSB Phone
mode needs to be ignored as it has
nothing to do with digital operations.
My main point is that if you can get
90W without ALC indication you are
pretty well guaranteed your signal is as
clean as it can get. And I've been able
to get 90W/No ALC on 99% of the rigs
I've dealt with.
de Mike W9MDB
On Thursday, June 13, 2019, 01:06:46
AM CDT, Roeland Jansen < [email protected]>
wrote:
so we agree that we
should follow the manuals of the
manufacturers?
On Wed, Jun 12, 2019
at 4:56 PM Black Michael via
wsjt-devel < [email protected]>
wrote:
I finally got a
reply from Kenwood
for the TS-990S --
this quite likely
applies to all the
Kenwood's with the
red ALC zone.
The
bottom of the meter
is 0dB ALC. I would
maintain once you
see the "beings to
swing" you back off
a bit for no swing.
You
won't find the PSK31
words in the
multi-lingual
manual...it's in the
English manual (and
perhaps the other
individual
languages).
It
tells you to set the
rig for almost no
ALC indication.
de
Mike W9MDB
Regarding
the ALC 0dB and
+6dB, refer to the
picture below.
![]()
In the TS-990S
instruction
manual, it is
mentioned as
follows.
---------------------------------------------
In the case of
operation in the
digital mode such
as PSK31 using
a PC, you must
adjust the audio
output level from
PC until the ALC
meter of the
transceiver begins
to swing.
---------------------------------------------
The level "begins
to swing" is not
zone max (+6dB)
but threshold 0dB.
There is a
common belief that
became an
internalized
misentrepretation:
"NO ALC", or even
"ALC is bad", this
can not be applied
to all rigs. On a
Kenwood rig the
manual says, you
should not go
(drive) the rig
beyond the
red bar.
For example, the
Kenwood TS990
audio input
setting to "no
ALC" will result
in an Power output
that goes down to
indeterminable
value, compared to
the
Po setting on the
front panel knob
& meter.
So please consult
your rigs manual,
the designers gave
you the right
info.
73 de Wolfgang
OE1MWW
----------
Amateur radio is
the most expensive
type of
free-of-charge
communication!
Amateurfunk ist
die teuerste Art
der kostenlosen
Kommunikation!
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