Chan_usbradio fixed for a "better" rxondelay

The feature here is a function to IGNORE RX for X milliseconds AFTER TX UNKEYS.

The rxondelay function is not sufficient due to the fact that it ignores rx audio independent if the transmitter has unkeyed or not. This causes audio cutoff when not necessary.

This is useful for linking simplex nodes to repeaters with a small squelch tail to prevent ping ponging.

Here is a better chan_usbradio.c that I just made which has added the function txoffdelay

Under usbradio.conf, please add txoffdelay=xxx where xxx is the number of 20ms intervals that you want to ignore RX only after TX UNKEY has occured.

Skyler W0SKY

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This is a nice addition to the channel. And I find this pretty interresting.

I hope it will be added to the github repo so that we can update our compiled version on our system.

Pierre VE2PF

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I had requested this feature a year or so ago, and David McGough implemented it on their image.

Obviously, I wouldn’t be able to get his code from him, I figured if he could do it, I could do it so I cobbled that together. Jeremy put it in his raslink image after I updated the usbradio file, he helped me with how to compile the stuff and what files I needed to look at since I’m not too savy, lol I need to learn to use git.

At the moment, “txoffdelay” is in the testing branch for RasLink. It will be in the RL-20.10 update. If you’re running RasLink, when you get the update, a commented out version of “txoffdelay” (as well as documentation on how to use it) will be added to your active usbradio.conf file.
If you’re not running RasLink, you can clone the RasLink source code from Just like ASL, RasLink is opensource. Feel free to use the code, as long as you FOLLOW THE GPL (versions 2 and 3).
@w0sky: I enjoyed developing the feature with you. Thanks for doing the code editing and testing with me.

Jeremy W0JRL
RasLink developer

You guys should submit a pull request, I have it on good authority (yes, mine lol) that it will be reviewed and accepted to the main branch. I also LOVE that you highlighted the GPL for all those code thieves lurking :wink:

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Pull request submitted to the asterisk develop branch.

Jeremy W0JRL


IS it now into the main branch?

Not yet. It will be merged when the next ASL release is ready, unless @KG7QIN or another maintainer decides otherwise.