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PGXL Interlock Prevents TX on MARS 2 MHz Frequency

Good evening,

The PGXL is working fine on all the other frequencies that I need to reach with respect to my Army MARS operations. Mostly in the 3 - 16 MHz range.

I'm now trying to reach down to the 2 MHz range because of the change in time of a net and the drop in the propagation support for any higher frequency.

When I configure the 6700 for the frequency the PGXL does not 'get' the band information to change down to the 160m segment I guess, and when I try to transmit with the PGXL in line I get a popup that says "Interlock is preventing transmisson" even if I have manually selected the 160m segment on the PGXL.

Seems like last winter it would work fine. I would only try to use about 600w max because of the external antenna tuner I was using, but it would transmit.

Any ideas as to what may have changed and/or how I can work around this obstacle?

I recently updated the PGXL Firmware to 3.4.16 but it was showing the same symptom in the previous firmware (3.4.10) that I was using.

Thank you!

Mark - N4EOC


  • W1XYZW1XYZ Member ✭✭
    Mark - I'm glad you raised this because at our acoustics lab we use HF amps into multiple high power ultrasound transducers for liquid coupled operation. These are used for tissue ablation, tattoo removal and other research where short, high powered acoustic pulses are needed. Two of the amps we use at 2.2 MHz is the ALS-1300 and ALS-1306, both which have no problem with that frequency but require manual control. We also have the RF-2K+ in remote mode via VNC. Now since I justify purchase of more ham gear through the lab use, can I expect to be able to use the PGXL in that mode - with an external RF source that is not a Flexradio, or is it locked out in the amp itself? Did you find your workaround? I will ask the salesperson this same question today. The PGXL looks like a great remotely controllable instrumentation amp that could cut our test time in half. I really want it in the lab (and then in the shack) de W1XYZ
  • MackMack Member ✭✭


    I just tested the 6600 and PGXL on 2.2 MHz into a dummy load. It did not fault and worked fine. I am running an Alpha code PGXL firmware which I don't believe is why it worked for me.

    Just a data point for you.



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