Bob Bob wrote:

Hi Dean

I assume you mean "sounds like 1200bps packet" rather than 2400?

Yeah, that is what I meant. I guess that when I was typing, my brain
was
faster than 1200bps AX.25! :-

I doubt this is relevant but I had some issues with using the serial
port for PTT under soundmodem. Ended up running setserial and turning
the serial port "off" before use. (ie "uart none") I'd think though that
baycom mode would be simply a "synchronous" form of transmitting to/from
a standard serial port and wouldnt need to be turned off this way..

Yep, doing that. I chose to load everything as modules, instead of the
kernel, so the first command in my script is "setserial /dev/ttyS1 uart
none". The Baycom driver is unhappy if it does not have the UART, so
this
is pretty much required.

Since the whole thing should be synchronous at 1200bps I'd start looking
for any inter bit delays that may be being introduced. This I think
would be more commonly a RX rather than TX problem. I remember having an
older kernel that didnt recognise the 16650 UART properly and defaulted
to something without either a RX or TX buffer. Perhaps some playing with
setserial will help (defining the UART type also defines whether it uses
buffering. I think the kernel module allows you to change the buffer
size but I havent checked this)

dmesg output indicates that the UART is recognized as a 16550 and that
ttyS1
is set to 1200bps when baycom_ser_fdx is loaded.

You may also be able to capture the audio with your soundcard and make
some hard comparisons with a spec-an etc to determine where it falls down.

I have not gotten around to configuring sound on this notebook yet.

If you think it may be linux version/kernel dependent try the Knoppix
boot CD. I think there is also a ham radio version if AX25 support isnt
in the original

I do have a copy of Harv's around, I may try that.

Apologies for not being more helpful
Cheers Bob W5/VK2YQA

All help is appreciated.

Dean KD4TWJ