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How to Request a New CAT Command?

Peter K1PGV
Peter K1PGV Member ✭✭✭
edited June 2020 in New Ideas
What's the proper way to request a new Flex-6xxx CAT command?

I would love CAT commands that:
1) Allow me to set the low and high frequency offset for receive on the active slice
2) Allow me to set the the low and high frequency offsets for Transmit on a the active slice.

These would be *very* useful when working digital modes.  This capability would allow you to center a station in your panadapter (using a command that you can issue in most digi-mode programs) and then set the width of the filters to exactly what you want using the newly proposed commands, all with a single macro invocation in your digital-mode program.

These wouldn't be difficult to add... and I would be happy to write and test the code, if that's of any help.

Any chance?

de Peter K1PGV


  • Stu Phillips - K6TU
    Stu Phillips - K6TU Member ✭✭
    edited May 2020

    There are CAT commands already supported that will set the low and high filter cutoffs on Receive.

    SH - sets the DSP filter high cutoff
    SL - set the DSP filter low cutoff

    You can find the full set of CAT documentation at:


    There isn't a CAT command that allows the transmit bandwidth to be set - but asking here is a good start!

    In the meantime, a couple of choices although not CAT viable.

    You can use the native Ethernet API to access all capabilities of the radio.  It is very simple to set the transmit bandwidth via a single command over the TCP port to the radio.  If you are comfortable programming, to do this, you need a TCP socket connection to the radio and then issue the following command over that socket:

    transmit set filter_low=200 filter_high=1000

    This sets the limits of the TX filter to 200 to 1000 Hz.

    My K6TU Control iPad app allows you to store user defined filters by using a profile (not to be confused with a SmartSDR profile).  The profiles in the iPad app allow you to store mode specific filters which include both TX and RX filter settings.  These can be selected from the iPad app during operation.  There's more information at http://k6tu.net/ipad/k6tuc-filters.html .

    At least the RX side answer is available now - within limits.  The SH and SL commands are Kenwood CAT compatible so there are limits on what values you can set - these are documented on the PDF guide to the CAT.

    Hope this sheds some light!
    Stu K6TU
  • Peter K1PGV
    Peter K1PGV Member ✭✭✭
    edited June 2020
    Thanks Stu.

    I'm aware of the SH and SL Kenwood commands.  The problem is that they're WAY too limited... they don't do what I need them to do.  I *really* want to be able to set arbitrary high and low offsets for both receive and transmit.

    I'd rather not take the "write it myself" for my own use approach... I could, for example, modify the provided Cat program for my own use (and then risk having to retroactively apply those changes to every new version, yuck)... or I could write my own Cat listener add-in (using a virtual serial-port "T connector", listening to every CAT command sent from the digi-mode program and respond only to my own private commands and manipulate the radio based on receipt of those commands).

    I think the commands I propose would be generically useful are easily implemented... and I'm hoping the Flex folks will consider adding them.

    Like I said, given that the Cat source code is available I'll be happy to write and test the code, and submit it for code-review and approval.

    de Peter K1PGV
  • Peter K1PGV
    Peter K1PGV Member ✭✭✭
    edited June 2020
    Bump... for no reply/comment/response in about two months.

    I can't help but notice that there have been a couple requests for added CAT commands, but there's never any reply from "the powers that be."

    Can somebody please explain under what circumstances or conditions a CAT command will be added?

    I've even volunteered to do the work for this one.  There's little/no risk, it doesn't duplicate existing functionality, and the interface to provide the feature in FlexLib is documented and supported.

    I would think it would be preferable for Flex to have some sort of control over this, instead of having the user community propagate all sorts of private forks of some version of the CAT program.


    Peter K1PGV
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited March 2017
    For any new feature or program change request, you add it as an Idea in the community and our product management team periodically will look at the ideas, the comments form the users and the number of votes in making a decision to consider having it put into SmartSDR.
  • Peter K1PGV
    Peter K1PGV Member ✭✭✭
    edited June 2020

    Thanks for the reply, Tim.  I appreciate it.

    Now at least I know that I should go create my own version of SmartSDR Cat.  This is only possible, of course, because Flex generously supplies us with the sources for the existing CAT program... which is *greatly* appreciated I assure you.

    Peter K1PGV

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