How I got WSJT working under MacOS Big Sur

First download the latest version of WSJT-X.app from 

https://physics.princeton.edu/pulsar/k1jt/wsjtx.html 

Then execute the ".dmg" file, this will open the install page. Drag the WSJT app to your apps folder. Then open the Terminal and do this: 

1. List long the file supplied on the download volume

ls -l /Volumes/WSJT-X/com.wsjtx.sysctl.plist

-rw-r--r--@  1 antonywatts  staff  543 28 Mar 12:53 /Volumes/WSJT-X/com.wsjtx.sysctl.plist

As you can see it has the "@" marker indicating special attributes, and has the wrong owner and group. The file as needed in /Library/Daemons is

-rw-r--r--  1 root  wheel  543 21 Aug 15:18 com.wsjtx.sysctl.plist

2. Copy the file to the correct location

sudo  cp  /Volumes/WSJT-X/com.wsjtx.sysctl.plist  /Library/LaunchDaemons

it has special permissions set - as seen by a '@' after the mode, as well as the wrong owner and group

-rw-r--r--@ 1 antonywatts staff ...

3. After copying the file to /Library/LaunchDaemons both issues must be solved. First change your directory

cd /Library/LaunchDaemons

and list the files using

ls -l

where you will see the things that are wrong with the .plist: the "@" and the wrong owner and group

4. Remove the special permissions "@"

sudo xattr -c com.wsjtx.sysctl.plist

and check that is has gone with another

ls -l ...

5. Set the correct owner and group

sudo chown root:wheel com.wsjtx.sysctl.plist

The result should be

-rw-r--r--  1 root  wheel  543 21 Aug 15:18 com.wsjtx.sysctl.plist

6. Now restart your Mac and check the settings with

sysctl -a | grep sysv.shm

If shmmax is not shown as 52428800 WSJT-X will fail to load with an error message: "Unable to create shared memory segment".  And you have to fiddle around a bit more.

UPDATE

I just bought a new Apple MacBook Air (M1 chip). On this the installation went more smoothly. I copied the com.wsjtx.sysctl.plist file across to /Library/LaunchDaemons (see #2 above). It arrived with right owner and group and no special permissions, and then I restarted the MacBook Air and the sysv.shm value had correctly been  updated.

So WSJT is right at least for new MacBooks.

Antenna switching unit

Ok so I have one decent antenna - an indoor AL-705 loop. But I have three things I want to connect it to

* My ELAD FDM-DUO SDR transceiver, possibly via my MAT-125E auto ATU

* My QPR-Labs QCX+ WSPR transmitter

* My NanoVNA, for tuning and checking the SWR to the loop

So I am building a switching unit. And for fun I am putting in it a stupidly simple resistor SWR bridge, with LED indication for high/low SWR which will also help with loop tuning (in addition to the power meter described below which still is, for now, the best way of optimising the matching)

Here it is. Without the three way switch which will mount on the right & I have ordered but which has not yet arrived

The red switch bypasses the small SWR bridge. I chose this green LED after trying a bunch from my scrap box as the brightest of the bunch, there was a notable difference between LEDs. I have standardised, good or bad, on BNC connectors, they are so quick and easy to plug/unplug when fiddling about.

Project finished, works great, now can switch antenna from ELAD for FT8, U3S for WSPR and NanoVNA for tuning.

More outputs

A later modification expanded the outputs to four, for my QRP-Labs WSPR TX, my Xiegu G1M, my ELAD FDM-DUO and the NanoVNA. Very convienient

Update to Power Meter (AD8307), EMF detector, loop tuner

My power meter has a direct input to an AD8307 Log Amp module. This gives a range of -80 to +20dBm sensitivity, with reliable measurements from -70 to +10dBm. 

AD8307 characteristics

To use it at higher powers attenuators can be used. These can be made with an high wattage input resistor of 50R, to act as the dummy load, a series resistor into the 50R input impedance of the AD8307 module in a resistor divider. The maximum input to the AD8307 is +10dBm or 10mW for linearity (it can tolerate 20dBm, 100mW).

The aim is for 10W in to give a reading of 10mW on the meter, this needs a series resistor of 2200+100R. I have checked the readings by comparison with the power output indication of my ELAD FDM-DUO SDR.

This is the screen layout, the small signal showing is from a short antenna connected to the input picking up local RF noise... The bar has a range of 100dB

Power meter display, Bar is -80 to +20dBm

The new Arduino code for the power meter called SIMPLE_WATT is here.

LOOP TUNING

A new use for the now sensitive power meter is to tune my AL-705 loop. I connect a short antenna to the power meter and place the unit close to the loop. On transmit (either by my FDM-DUO 5-8W, or my new U3S WSPR TX 250-200mW) it deflects and allows me to tune the loop using my new remote motorised capacitor controller (see below)

Great stuff.

So how is the WSPR/PSK going?

 I have started on a more longterm project to look for myself into my propagation and reach. This is somewhat limited as I cannot mount outside aerials and I use only an indoor AL-705 loop.

These are the long term graphs I have right now for spots on WSPR, from my U3S 200mW 30m station and from my ELAD FDM-DUO 5W FT8 station

WSPR 200mW

WSPR

PSK FT8 5W

Thanks to Paul Marks down in VK land for the development of an excellent Mac app "WSPR Watch" for these graphs. More to come as I leave the WSPR on for a week or so (occupying the loop so no FT8..)