[App_rpt-users] Squelch tail elimination

[Tom Hayward]

I'd like to add some audio delay to get rid of a nasty squelch tail. I
figured this would be easy, but the documentation is rather sparse.
Reading mailing list archives, I've found mention of an rxaudiodelay
or rxsquelchdelay parameter for usbradio.conf. Haven't seen anything
similar for simpleusb.conf. Searching for actual documentation of
these parameters hasn't turned up anything. Do they exist? How do I
use them? Is there another way?

Nothing here:
http://docs.allstarlink.org/drupal/search/node/rxaudiodelay
http://docs.allstarlink.org/drupal/search/node/rxsquelchdelay
nor here: http://docs.allstarlink.org/drupal/node/73

I did find some mention in the code...
Toms-MacBook-Pro:astsrc-1.4.23-pre tom$ grep rxaudiodelay -R asterisk/channels
Toms-MacBook-Pro:astsrc-1.4.23-pre tom$ grep rxsquelchdelay -R asterisk/channels
asterisk/channels/chan_pi.c: int rxsquelchdelay;
asterisk/channels/chan_pi.c:        M_UINT("rxsquelchdelay",o->rxsquelchdelay)
asterisk/channels/chan_pi.c: tChan.rxSquelchDelay=pvts[i].rxsquelchdelay;
asterisk/channels/chan_usbradio.c: int rxsquelchdelay;
asterisk/channels/chan_usbradio.c:
M_UINT("rxsquelchdelay",o->rxsquelchdelay)
asterisk/channels/chan_usbradio.c:
if(o->rxsquelchdelay>RXSQDELAYBUFSIZE/8-1)
asterisk/channels/chan_usbradio.c:
ast_log(LOG_WARNING,"rxsquelchdelay of %i is > maximum of %i. Set to
maximum.\n",
asterisk/channels/chan_usbradio.c: o->rxsquelchdelay,RXSQDELAYBUFSIZE/8-1);
asterisk/channels/chan_usbradio.c: o->rxsquelchdelay=RXSQDELAYBUFSIZE/8-1;
asterisk/channels/chan_usbradio.c: tChan.rxSquelchDelay=o->rxsquelchdelay;

But it's not much to go off. Looks like I would at least have to
switch from simpleusb to usbradio to test it?

And in the changelog here there mention of audio delay for squelch
tail elimination:
http://www.crompton.com/hamradio/BeagleBoneBlackAllstar/
"BBB V1.2.2 - simpleusb Channel Driver update to eliminate echo on
repeaters, added pre-emphasis and audio delay squelch tail
elimination, fixed phone and web transceiver codec problem"

But again, I haven't been successful in matching this to source code
or documentation. I have the app_rpt SVN repo downloaded. Where can I
find the Crompton code fork? (Is it a fork?)

Tom KD7LXL