Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please refer to the product documentation or check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

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


  • W1XYZ
    W1XYZ 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
  • Mack
    Mack 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.



  • Mark
    Mark Member ✭✭

    W1XYZ - no workaround for me. Reply from FLEX was essentially that it doesn't work DC to light. I guess the frequency I wanted to use was outside any of the bandpass (or other) filters.

    Good luck!


  • Mark
    Mark Member ✭✭

    Mack - W4AX,

    Thanks, that's great. I have the latest firmware which might be a factor. See my reply comment to W1XYZ.



  • WX7Y
    WX7Y Member ✭✭✭✭

    work here as well but didn't go over 300 Watts to test.

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.