During the last months, I was trying to configure the 9k6 port
of my USCC card. It was a pain!
Until now, I'm the only user of the 9k6 channel here; so, I had
no references of which end of the link was broken: mine, or the
gateway at the local university.
Here is the complete saga:
System: 386DX40, 8 MB RAM, 340 MB HD, Linux Slackware 2.0.29
Radio Tekk KS900, modified for 431.900 MHz
After installing the radio system, wiring it to the board and
configuring the 9k6 port, the headache starts!
I can connect to gateway, but the connection hungs, and I have
to reset it. Using ping, I can see that there is about 40%-50%
of lost packets (64 bytes long packets) and 60%-80% lost packets
using 208 bytes long. Reducing packet size to 16 bytes, the loss
drops to 25%-30%, but it is a very high rate.
The radio was returned to the dealer, checked the tuning, and
tested using BayCom in the dealer facility. It works.
Reinstalled in my system, the problem persists.
Next, I checked the gateway end of the link. The radio and TNC
were checked and tuned, parameters adjusted, put TNOS as front-end
instead of connecting to the kernel - same results.
The mainboard of the computer was changed to a 486DX2-66, because
a note in the docs of the USCC drivers says that some 386s has
bogus buses, leading to troubles with the card. Tried compiling
DL1BKE's USCC driver versions 2.0, 2.2, 2.4 and 2.4c with all
delay combinations and all sort of parameters adjusting. No results.
Trying Baycom under DOS, the system works well, but I need TCP/IP,
not AX25.
Installed an internal 10 VDC regulator and indicator LEDs for DC
power, CD, TX and RX in the radio, to help observe signals.
The radio was again fine tuned, and observed their frequency
stability - it remained two hours working, connected to a SINAD
analizer, without problems.
Next, I decided to upgrade the kernel, and installed RH6.0, kernel
2.2.5. To achieve this, I had put another HD to obtain more space,
and a monster(!) 540 MB was added to existing 340 MB.
Got DL1BKE's USCC driver version 3.0, and compiled it into the
kernel. No deal. Tried compiling again, with adicional delay for
PE1HCL's like card defined. No deal.
Before throw in the towel, I tried again some adjusts in the
port parameters.
After defining softdcd ON, here is it: the port is working well!
Finally, after 6 months of pain, I got my 9k6 port working, with
less than 3% of packet loss, no matter how long is the packet length.
I have to thank to all people that helped me with ideas and tips.
I'm just sending this to help anyone that could having trouble
with an USCC card.
Happy New Year to all!
