Juma PA-100D and KX3 CAT problem

[R9HCH]

Hello JUMA users !
I have a Elecraft KX3 and a Juma PA-100D amplifier. When connected KX3 with PC only with a native cable to the ACC1 socket, the transceiver can be easily controlled from a computer via OmniRig. Accordingly, when connecting to the ACC1 socket only with a cable for connecting to an amplifier for automatic band switching, the bands on the amplifier switch automatically follow the transceiver without any problems. But if I connect both cables to the ACC1 jack through a splitter (3.5 mm “male” to 2x3.5 mm ”female”), OmniRig refuses to work (the computer "does not see" the transceiver, the COM-port does not respond). The amplifier in this situation could be made to automatically switch bands only by turning off "polling" in amplifier menu and turning on "Ant ctrl" in the KX3 settings in the "autoinform" menu item. But how to make control from a computer work when connected through a splitter to an ACC1 socket?

[5B4AIY]

Hi,
If you are using my firmware for the PA-100D it is possible to retrieve band information as well as have the KX3 work with Omnirig. You will need to make yourself a cable from the KX3 serial data output so that the TX Data from the KX3 is fed to the RX Data input of the PA-100D as well as to your PC. The PA-100D is now just 'listening' to all the data from the KX3 on the serial link to the PC, and will respond to any VFO-A frequency data.

The PA-100D is specifically listening for a message of the form: FAnnnnnnnnnnn; where nnnnnnnnnnn is the VFO-A frequency to a resolution of 1Hz. Note that in this mode of operation the TX Data line from the PA-100D is not used! The Omnirig module will be sending ASCII data to the KX3 requesting various pieces of information, and at some time it will send the VFO-A frequency request command: FA; and it is the response to this command that will be picked up by the PA-100D and used to set the band. All other data will be rejected.

Unfortunately I cannot check with my KX3 because it is badly damaged and needs some spare parts which I am awaiting, but I wrote the software with a view to this mode of operation. I hope this helps.
Adrian, 5B4AIY

[R9HCH]

I made a cable that only uses Rx Data for the Juma PA-100D. After that everything worked without problems. Thanks for the help and great firmware!