Topics

WSJT-X Audio Output Reduces


Mark
 

My WSJT-X audio level starts out at the desired level, but it declines substantially during the 15 second cycle.  That, of course, reduces the RF power out of the transceiver.

 

Does anyone also have that experience?  If so, what is the fix?

 

Tnx & 73,

 

Mark, K6FG


Michael Black
 

What rig?
What power level?

Could be thermal control?

Mike W9MDB




On Thursday, February 18, 2021, 11:34:44 PM CST, Mark via groups.io <m.weiss@...> wrote:


My WSJT-X audio level starts out at the desired level, but it declines substantially during the 15 second cycle.  That, of course, reduces the RF power out of the transceiver.

 

Does anyone also have that experience?  If so, what is the fix?

 

Tnx & 73,

 

Mark, K6FG


Michael Black
 

Also...wrong email group...that's a wsjt-x question.

Mike W9MDB





On Thursday, February 18, 2021, 11:34:44 PM CST, Mark via groups.io <m.weiss@...> wrote:


My WSJT-X audio level starts out at the desired level, but it declines substantially during the 15 second cycle.  That, of course, reduces the RF power out of the transceiver.

 

Does anyone also have that experience?  If so, what is the fix?

 

Tnx & 73,

 

Mark, K6FG


Roger M
 

Maybe your rig's ALC is set right on the hairy edge, where it starts to drop power. Try increasing the audio level just a little, to increase ALC a bit.
--
73,
Roger
AC6BW


Michael Black
 

If it's ALC it would more likely be that audio level is too high and the ALC starts reducing it slowly.

Mike W9MDB




On Friday, February 19, 2021, 10:56:52 AM CST, Roger M via groups.io <ac6bw@...> wrote:


Maybe your rig's ALC is set right on the hairy edge, where it starts to drop power. Try increasing the audio level just a little, to increase ALC a bit.
--
73,
Roger
AC6BW


Fred Roberts
 

Mark,
     What is the ALC level of the audio? Are you using an amp, and if so, is the ALC line connected?
Fred
WB4QOC



Sent from my phone.....Fred


On Fri, Feb 19, 2021, 12:34 AM Mark via groups.io <m.weiss=yahoo.com@groups.io> wrote:

My WSJT-X audio level starts out at the desired level, but it declines substantially during the 15 second cycle.  That, of course, reduces the RF power out of the transceiver.

 

Does anyone also have that experience?  If so, what is the fix?

 

Tnx & 73,

 

Mark, K6FG


Bill Mader
 

It is well-documented that using ALC to control power levels frequently creates IMD and its resultant  QRM.  ALC from a transmitter to an amplifier should be set and used to prevent accidentally over-driving the amplifier.

Using a dummy load, adjust TX audio levels so that ALC just begins to show.  You'll note that this level occurs when reducing TX audio begins to reduce power output.  That point prevents unnecessary splatter (IMD) regardless of the SSB mode.

I'm looking at an FT8 signal on 30m as I write this that is twice as broad as it should be and I'll bet the op's ALC is way too high.  Listen to 20m and you'll find all kinds of signals with over-driven ALC, many of them created by the ALC Voltage creating distortion in the amplifier to add to the distortion created in the rig.
--
73, Bill, K8TE


Michael Black
 

ALC is the canary-in-the-coal-mine -- symptomatic and not the cause.

Here's our paper on setting audio levels that works on every rig in existence.  Some rigs have to have ALC like Elecraft.


Mike W9MDB


On Saturday, February 20, 2021, 08:30:32 AM CST, Bill Mader <billamader@...> wrote:


It is well-documented that using ALC to control power levels frequently creates IMD and its resultant  QRM.  ALC from a transmitter to an amplifier should be set and used to prevent accidentally over-driving the amplifier.

Using a dummy load, adjust TX audio levels so that ALC just begins to show.  You'll note that this level occurs when reducing TX audio begins to reduce power output.  That point prevents unnecessary splatter (IMD) regardless of the SSB mode.

I'm looking at an FT8 signal on 30m as I write this that is twice as broad as it should be and I'll bet the op's ALC is way too high.  Listen to 20m and you'll find all kinds of signals with over-driven ALC, many of them created by the ALC Voltage creating distortion in the amplifier to add to the distortion created in the rig.
--
73, Bill, K8TE


Roger M
 

FT-450D is another rig that needs some ALC, otherwise power output will drop. It needs to be at least 1/3 of full scale.


On Sat, Feb 20, 2021 at 06:33 AM, Michael Black wrote:
ALC is the canary-in-the-coal-mine -- symptomatic and not the cause.
 
Here's our paper on setting audio levels that works on every rig in existence.  Some rigs have to have ALC like Elecraft.
 
 
Mike W9MDB
 
 
On Saturday, February 20, 2021, 08:30:32 AM CST, Bill Mader <billamader@...> wrote:
 
 
It is well-documented that using ALC to control power levels frequently creates IMD and its resultant  QRM.  ALC from a transmitter to an amplifier should be set and used to prevent accidentally over-driving the amplifier.

Using a dummy load, adjust TX audio levels so that ALC just begins to show.  You'll note that this level occurs when reducing TX audio begins to reduce power output.  That point prevents unnecessary splatter (IMD) regardless of the SSB mode.

I'm looking at an FT8 signal on 30m as I write this that is twice as broad as it should be and I'll bet the op's ALC is way too high.  Listen to 20m and you'll find all kinds of signals with over-driven ALC, many of them created by the ALC Voltage creating distortion in the amplifier to add to the distortion created in the rig.
--
73, Bill, K8TE

 
--
73,
Roger
AC6BW