USBRadio Channel Driver
From "AllStarLink Wiki"
Chan_usbradio is a feature rich DSP radio interface.
It requires more CPU than chan_simpleusb and therefor chan_simpleusb may be a better choice on smaller computers. Chan_usbradio.conf setting are well documented in the configuration file itself.
; ; Usbradio channel driver Configuration File ; [general] [usb] hdwtype=0 ; Leave this set to 0 for USB sound fobs modified using ; the instructions from usbfob.pdf. Use a setting of ; 1 is for Dingotel/Sph interfaces. rxboost=1 ; 0 = 20db attenuator inserted, 1= 20db attenuator removed ; Set to 1 for additonal gain if using a low-level receiver output rxctcssrelax=1 ; reduce talkoff from radios w/o CTCSS Tx HPF ; Do not change this, leave this as a 1 txctcssdefault=100.0 ; default tx ctcss freq, any frequency permitted rxctcssfreqs=100.0 ; rx ctcss freqs in floating point. must be in table txctcssfreqs=100.0 ; tx ctcss freqs, any frequency permitted ;rxctcssoverride=0 ; Set to 1 or yes to start out in carrier squelch mode carrierfrom=dsp ; no,usb,usbinvert,dsp,vox ; no - no carrier detection at all ; usb - from the COR line on the modified USB sound fob ; usbinvert - from the inverted COR line on the modified USB sound ; fob ; dsp - from RX noise using dsp techniques ; vox - voice activated from RX audio ctcssfrom=dsp ; no,usb,dsp ; no - CTCSS decoding, system will be carrier squelch ; usb - CTCSS decoding using input from USB FOB ; (currently not supported) ; dsp - CTCSS decoding using RX audio in DSP. ; rxdemod option must be set to flat for this to work. rxdemod=flat ; input type from radio: no,speaker,flat ; no - RX audio input not used ; flat - Use RX audio from discriminator (before de-emphasis) ; speaker - use de-emphasized audio txprelim=yes ; Audio processing on left output channel: no,yes ; no - Audio is not pre-emphasized and limited. ; Suitable for use on a microphone input ; yes - Audio is pre-emphasized and limited. ; Suitable for direct connection to an FM modulator txlimonly=yes ; Audio limiting with no pre-emphasis on output channel: no,yes ; no - Audio is not limited. ; yes - Audio is limited. ; Suitable for transmitters with no limiting but with pre-emphasis. txtoctype=notone ; Transmit tone control type: no,phase,notone ; no - CTCSS tone encoding with no hang time ; phase - encode CTCSS and reverse phase ; AKA ("reverse burst") before unkeying TX ; notone - encode CTCSS and stop sending tone before unkeying TX ; AKA ("chicken burst") txmixa=composite ; Left channel output: no,voice,tone,composite,auxvoice ; no - Do not output anything ; voice - output voice only ; tone - CTCSS tone only ; composite - voice and tone ; auxvoice - auxiliary voice output at headphone level for monitoring txmixb=no ; Right channel output: no,voice,tone,composite, auxvoice ; See txmixa above. invertptt=0 ; Invert PTT 0 = ground to transmit, 1 = open to transmit ; This is the collector lead of the 2n4401 on the modified ; usb sound fob. ; please refer to the howto for the procedure to do this. duplex=1 ; Full Duplex ;rxondelay=20 ; Uncomment and/or adjust for simplex nodes to eliminate "Ping ; Ponging" or "Relay Racing". ; A positive value here will instruct the usbradio driver to ignore ; the COR line for a specified number of 20mSec intervals following ; the release of PTT. Use this only on simplex nodes, and ; leave commented out for repeaters or other full duplex nodes.