Resending this to Blacksheep, in case anyone else wants to try it too. The mentioned .ini configuration file and a screenshot are at
 http://df6nm.bplaced.net/VLF/vo1na/_vlf_tx_pll_ini.zip
 http://df6nm.bplaced.net/VLF/vo1na/vlf_tx_pll_8270.007Hz.png

73, Markus (DF6NM)

Hi Joe,

DL0AO is online again! So if you send another carrier there's a chance that it might also be picked up in Heidelberg or Amberg. Renato's grabber in Cumiana is also quite sensitive but the display range ends just above 8270.005. So you might want to go a little lower, e.g. to 8270.00375.

The ini file which I sent to you will also support EbNaut PSK with phase stabilisation, as used by Stefan and myself. To enable it, you need to

- Install an NTP utility to keep the PC clock within a fraction of a second.

- Use Paul's ebnaut-tx encoding program and use "Save Rows" to store the result in a file "pskln.txt". This will have one line per symbol, containing either 0 or 1. 
  - copy that file to SpecLab's main folder (e.g. c:\spectrum).

- Open SpecLab's Periodic Actions under the leftmost "File" menu:
  - set the time interval to the desired symbol duration (e.g. 00:01:00 for 60 seconds),
  - in case you have already uncommented the a=1-a line then disable it again, 
  - tick the "active" box to enable periodic actions and press Apply or Ok,

- Set up Scheduled Actions:
  - edit the Time of day in the first line to about one second before the start of the transmission (e.g. 01:59:59 if you want to start at 2:00:00 UT),
  - edit the command in the Action line to 
     fopen("pskln.txt") 
    In case there are more commands in that line after a colon (e.g. to change frequency) you can remove them,
  - if you want to shut down the carrier after the end of the transmission, you can set up a second action line with the command
     a=0.5 
    (half way between 0 and 1 produces zero output), 
  - activate scheduled actions and Apply.

Please don't modify any of the conditional actions because these are running the PLL script.  If you want to see it at work you can open the Command Interpreter window under the View/Windows menu. 

Well that should do it...

Best 73,
Markus
...