locked Re: Problems with JTAlert latest install

Jim Wysocki

Thanks for the quick response.  Here are the answers to your questions.

The CPU usage never topped 24%, with most of the load coming from WSJT-X's decoding engine at 12% -14%.  JTAlert's usage typically never rose about 1.5%.  In terms of memory, everything running on the computer only brought the memory percentage above a few percent.  Memory usage never got above the single digits.

I did two PC restarts to see what would happen.  There was no change in JTAlert's behavior, from before to after the restarts.

Thanks for the explanation of the user interface redesign and the replacement of the old call signs window with the stand alone, resizable one.  I presume that it's different from the Decodes window.  I've seen "Decodes" but not "Call Signs".  Hopefully that situation will change soon.

I was running version 2.16.14 before the 2.50.3 install.

I hope these clues help in the problem solving process.

73,  Jim  W9FI

On 7/13/2021 4:31 PM, HamApps Support (VK3AMA) wrote:
On 14/07/2021 8:27 am, Jim Wysocki wrote:

I've been using JTAlert with WSJT-X for several years without any problems at all, until last night when I updated to version 2.50.3, 64 bit.  Several problems now have appeared.

There is a general sluggishness to JTAlert's main window.  In contrast to all of the others on the desktop, when this one is grabbed and moved around, there is a 1 or 2 second delay in its response.  The same is true of when it has focus and the mouse is scanned across the tabs from Alerts to Help.

The call signs windows that was immediately below the main window in the old version has disappeared, and pressing F3 will not make it show up.  The Decodes window can be made to appear by clicking on its option off of the View tab, but it has problems.  The decoded transactions that come to it from WSJT-X appear late and at intermittent times.  Every once in a while it will partially synch with WSJT-X, generally showing up to four of the latest callsigns that WSJT just decoded.  Occasionally JTAlert will grab more of them.  Most of the time it runs between one and six time slices behind WSJT.  Then it will grab about four of the latest transactions before locking up again.  It cannot respond in real time with the data feed from WSJT-X.

Here is some background information for the problem analysis.

I am running a fully-updated Windows 10 Professional (64-bit) machine, an i5 with four processors at around a 3.3 gig speed and 16 gb of memory.  Task manager shows no memory or processor bottlenecks.  Windows desktop Dotnet runtime version 5.0.7 64 bit has been installed without any problems.  The JTAlert Framework Check displayed the "Good News" screen at the time that version 2.50.3 was installed.

Both WSJT-X and JTAlert have been whitelisted on PCMatic SuperShield.  The Windows Defender firewall has been directed to allow the HamApps software apps to pass through it.  Just to make sure I've also disabled Defender from running on the computer's private network.

WSHJT's UDP server address is Its UDP server port is 2237. Its secondary server is disabled.  The "Accept UDP addresses", "Notify on accepted UPD Request", and "Accept UDP Request Restores Window" options are all checked. 

On JTAlert, the Select menu's "WSJT-X  UDP Multicast on Loopback" option is checked.  In its Settings/Applications/WSJT-X / JTDX" section, all of the options are selected except for "Resend WSJT-X UDP Packets..." .  The value in the greyed-out IP address is, and the greyed-out UDP port's value is 2233.  None of these six checked options appears to control information in the Decodes screen.  As mentioned before, the Callsigns Window is no where to be seen.

Since this latest version was installed over the previous one, I used the Windows "Add or Remove Programs" utility to remove JTAlert, and then installed it again via

It appears to be that the transaction flow from WSJT and JTAlert is getting disrupted in some way, but I can't determine how this is happening.  I'm at a loss as to where to proceed from here so I need some advice.  What can be done next to diagnose and resolve this problem?

Thanks and 73,  Jim  W9FI


Thanks for the detailed message. You have answered some of the questions I would have asked. Thanks for making the effort to read the group messages and attempt diagnosis before posting.

What is the CPU usage of JTAlert when it is sluggish or non-responsive?

Have you done a PC restart?

I note you said the "The call signs windows that was immediately below the main window in the old version has disappeared". That is correct, that display was retired when JTAlert 2.50.0 was released as it includes a standalone resizable no callsign display limit window called the "Callsigns" window.

Since you asked about the old inbuilt callsign display suggests that you upgraded from a pre 2.50.x release of JTAlert. Is that the case? If so what version were you running before the 2.50.3 install?

de Laurie VK3AMA

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