Neil, I did some poking around in allstar (HAMVOIP version) and found these two files. This is from a allstar node that has a working SHARI attached. Maybe you can compare to your files and see if the URI setup has one of these parameters set in a way that the USB does not work for the SHARI. If all else fails, make a new SDcard and start over. I build portable Allstar nodes every day to play with different options. I have it down to about 10 minutes from making the SDcard to a running node.
txdsplvl=999
file?/etc/asterisk/simpleusb.conf
[usb]
?
;?
?
?
eeprom=0
; 1 = Indicates that an EEPROM internal to the radio
;? ? ?adapter and cable is expected.?
; 0 = no warning message if no EEPROM found.
?
rxboost=0
; Rx Audio Boost
; 0 = 20db attenuator inserted?
; 1 = 20db attenuator removed
; Set to 1 for additonal gain if using a low-level
; receiver output.
?
carrierfrom=usbinvert
; Options - no,usb,usbinvert?
; no - no carrier detection at all
; usb - via USB radio adapter COR connection
; usbinvert - same as above but inverted polarity.
?
ctcssfrom=no
; CTCSS Decoder Source
; Options = no,usb,dsp
; no - CTCSS decoding, system will be carrier squelch
; usb - CTCSS decoding using input from USB adapter?
; usbinvert - same as above but inverted polarity.
?
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.
?
plfilter=no
; enable PL filter
; yes, enabled
; no, disabled
?
deemphasis=yes
; enable de-emphasis (input from discriminator)
; yes, enabled
; no, disabled
?
preemphasis=yes
; enable pre-emphasis (output to Tx)
; yes, enabled
; no, disabled
?
rxaudiodelay=0
; default value is 0
; rx audio delay for squelch tail elimination.
; Squelch tail delay in 20ms frames. Values range
; from? 0 (no delay) to 24 (480ms delay)
; Typical values would range from 5-10 (100-200ms)
W8DSB