Station radio-amateur ON4NB
membre du GDV, "Gang de Verviers"
QRA-Locator : JO20WN
Digimodes, PSK31, SIM 31/63-CAT

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Using CAT on Flex-radio

The SDR transmitters like Flex-radio can communicate with our software "SIM-PSK31" like "digital master" and some other softwares thru a pair of virtual COM ports created by a third party software.

This third party software allows to assign a first virtual COM port to "PowerSDR" which manages the FLEX RADIO, and a second COM port to our software "SIM-PSK31”.

Software Tested to create and manage the serial ports:

- The shareware "Virtual com port" from ETHERLOGIC is also dedicated to this task, but it has not been possible to set it up properly despite a license number legally acquired .
So we can not recommend it since it does not work.

- "COMoCOM" (unsigned for windows) is a freeware running perfectly, and moreover, it is recommended by the company producing the FLEX RADIO.
It is therefore highly recommended to use this program COMoCOM.
You can download COMoCOM since:

The "flex radio" documentation can be downloaded at the following address:

If you install the program under Windows 7 or Vista 64-bit,
it is necessary to execute the command line: bcdedit.exe -set TESTSIGNING ON

Click "Start" and then type in the above command in "RUN window" .
It passes windows in test mode and allows unsigned software settings.

After this setting only, it will be possible to create a pair of serial ports :
eg "COM1" and "COM11".
In the Flex configuration, check «Enable CAT» et choose «COM1»,

See parameters below :

Open the program "SIM-PSK31."
In the first configuration window, Interfaces setting, select "CAT" as below:

Then in "COM PORT", select "COM11".
Then, in the two windows
Enter the following hexadecimal strings :
- For TX ON: 5A.5A.
- For TX OFF: 5A.5A.

As indicated, each hexa command string switches the PTT ON or OFF, the same way you van do it with button "MOX" of the FLEX sdr.
Note: Be sure to follow the right syntax: each byte is separated by a dot.

To control and choose the correct CAT MODE and filtering on FLEX, You must still select SIM-PSK31 port "DIGU" as shown below:

The audio signals are available via channels line 1 (RX) and line2 (TX), created by the software "virtual audio cable" which can be download at the following address:

Here is the setup of "virtual audio" software recommended by FLEX RADIO :

In the "setup" of PowerSDR, you must configure VAC (virtual audio cable) as follows:
- In "Input", selected Line 1
- In "Output"selected Line 2

In the configuration of "SIM-PSK31", window "general interface settings",
You must choose:
- In input Sound Driver : Line 2
- In Outpout Sound Driver : Line 1

Installation Summary :


Thanks to Didier, ON5DVO, whom gave me all the necessary informations
about FLEX-radio for the publication of this article.



Optimisé pour un affichage en 1024 x 768 points Dernière mise à jour: 12/02/2013