Bulletin:  SK1001
Vendor:    Kantronics
Subject:   Determining Unknown Signal Baud Rate

Hello KAM owners

     Most KAM owners have taken some flack from PK-232 owners
about how "awesome" their SIAM mode is.  Well I have come up with a
way to AT LEAST get the baud rate of an 'unknown' signal.

     If you look at the CPU/VHF modem page of your Installation book
you will see a connector marked as "External Modem".  The connector number
in my book is illegible but you will find it near the upper right corner.
Follow pin 14 back to the inverting op-amp called U2C.  If you were to
follow the circuit back you would find that this (pin 14) is an inverted
version of the filtered and discriminated (read "cleaned-up") input signal
that feeds the main processor!  This inverter is an ideal place to look at
the KEYED DC signal that most bauded signals (ARQ/FEC/BAUDOT etc) start their
short lived lives as.  Put another way we can now use our scope to look at
an accurate picture of the signal we are copying.  This signal has a pretty
fast rise time allowing us accurate measurement of the length of the
mark pulses. Simply divide this mark length (in milliseconds) into 1000 to
get the keying speed!  Simple.   1000/22.2 (ms)=45 baud
                                 1000/13.3 (ms)=75 baud etc.

     To get this +2.3 volt DC signal out of my KAM I used PIN 9 of the
25 pin COMPUTER connector. From there use shielded cable to your scope we
don't want any RF getting near that microprocessor!  You might want to use
a 100K ohm resistor as with the "scope monitoring" MOD.
     Also if you need to calibrate that cheap scope the KAM is VERY
accurate at baud rate generation and reasonably accurate at frequency
generation (+/- 10 hertz).

     Please let me know if you have any questions and remember all
non-factory approved MODS are to be done at your own risk.

73's DE Gary  G0MHI @ GB7ZPU.#21.GBR.EU