WSJT application on MacOS (sysctl.conf workaround)

Software download and install (MacOSX details)

WSJT-X makes use of a block of memory which is shared between different parts of the code.  The normal allocation of shared memory on a Mac is insufficient and this has to be increased.   So you will need to modify your sysctl.conf file.
When you downloaded wsjtx it includes a ReadMe.txt file and sysctl.conf file. Please, read the instructions in the "readme". Basically these are the steps at the moment I wrote this article:

1. Copy sysctl.conf  to your desktop.
2. Open sysctl.conf with a text editor.
3. shmmax determines the amount of shared memory that must be allocated for WSJT-X to operate.  This is 14680064 (14MB) and should not be changed.
4. It is possible to run more than one instance of WSJT-X simultaneously.  The parameter that controls this is shmall=17920 . The max. number of instances is (shmall x 4096/14680064)=5.
5. If 5 is not good for you, then you must edit the file according to this calculation.
6. Once sysctl.conf  is ready:
1.   sudo cp "$HOME/Desktop/sysctl.conf" /etc/
2.   sudo chmod 664 /etc/sysctl.conf
3.   sudo chown  root:wheel  /etc/sysctl.conf
7. Reboot your Mac
8. Check changes has been made correctly:
1. sysctl -a | grep sysv.shm
9. Drag the WSJT-X app to your preferred location, such as Applications.
10. Configure sound card:
1. Visit Applications > Utilities > Audio MIDI Setup and select your sound card and then set Format to be "48000Hz 2ch-16bit" for input and output.
2. double-click on the WSJT-X app
3. IMPORTANT: If you are using macOS 10.14 (Mojave) it is important to note that the default setting for audio input is "block".  In order to receive audio from WSJT-X you must visit System Preferences > Security & Privacy > Privacy and, with WSJT-X launched, select "Microphone"under Location Services and wsjtx should appear in the panel.   Check the "Allow" box.  You will have to quit WSJT-X for this change to take effect.
4. Visit the Audio panel and select the Audio Codec you use to communicate between WSJT-X and your rig

WSJT Home page: https://physics.princeton.edu/pulsar/K1JT/wsjtx.html