QA40x Release 1.164

Release 1.164 has posted at the link below. Automated measuring of both SMPTE and ITU IMD is included. You can specify the order of the harmonics you’d like to consider. In the lower right of the IMD plot, you’ll see the frequencies that were considered in calculating the IMD. In the plot below, note that 3rd order harmonics were specified, and with an ITU IMD test (19 and 20 kHz tones), that means 1 kHz and 18 kHz are specified.

In the Options setting for the IMD plug-ins, if you click Help it will take you to the QA40x wiki on Github (located HERE that will go into more detail on the operation of the IMD plug-ins, order of the harmonics calculations, etc.


One more point–you can now hover over the measurement tiles and see a “tool tip” giving a short summary of what the measurement is showing. It can be very confusing at times I know, and hopefully the short messages help.

One source of confusion is that there has been the measurement called “Peak Power (Watts)” that shows you the power of a single peak. For the IMD measurements, a new measurement tile was added that lets you measure the power over a range of frequencies. This might be useful for verifying IMD dual tone power.

Hi @matt. I have downloaded and installed version 1.164 of the software QA40x. But when I go to load my settings from “File” “Load Settings…” command, the new version does not load them and gives me this error. Thanks

screenshot with version 1.161

screenshot with version 1.164

Hi @Claudio, can you please send the settings file that is causing you problems to the support at quantasylum email? Thanks for noting this!

Hi @Matt. Sent the file at But all the settings files created with the previous version do not work and give the same problem when loaded into the QA40x 1.164 version.
Thank you

Matt, I don’t know if this information can be useful.

I created the same setting file with the new version of the software and it is now loaded regularly.

But whereas 6 measurement tiles were displayed for each row in the previous version (1.161), 5 measurement tiles are displayed for each row in the new version (1.164).

I do not know if this gives any clue



Hi @Claudio, thanks for reporting this and helping to figure this out in email. There were two bugs that were causing a problem here. The first bug was that when the hardware wasn’t connected, loading a .Settings file caused an exception. The second bug was that when a settings file that used LPwrWatts or RPwrWatts was opened, another exception was generated.

The first issue (HW not connected) was fixed in 1.165. But if you have old (pre-1.164) .Settings files, they will need to be manually updated to allow them to load. The release page at Github shows how this can be done. It’s located HERE

Thanks very much for reporting this, and sorry that your older settings files don’t work in this release. If you need some additional instructions on how to convert them, please just ask.

Hi @Matt. I downloaded and tested version 1.165. Everything is fine now. Thanks Matt

Where is the download button located?

Hi @JEJ, go to the link HERE and click the link at the bottom of that page. That will download the EXE.