AMT1.8
12)  THIS ONE IS EASY.  MOUNT ANOTHER RCA JACK ON THE BACK PANEL AND
RUN A WIRE TO POINT B OF THE MATRIX SHOWN IN THE MIDDLE OF THE UPPER
LEFT QUARTER OF SHEET 3.  THATS ALL THERE IS TO IT.  IT WILL PROVIDE
TTL OUTPUT LEVEL TO THE XCVR FOR FSK.  IF OPPOSITE POLARITY IS
NEEDED YOU CAN USE POINT A ON THE MATRIX.  BUFFERING MIGHT BE WISE
BUT NO PROBLEM HAS OCCURRED ON THE ONE I MODIFIED.13)  THIS MOD IS NEEDED ONLY IF YOU HAVE A STRONG SQUARE WAVE SIGNAL
APPEARING ON TP6, THE OUTPUT OF THE ACTIVE FILTER (SHEET 1, TOP,
RIGHT OF CENTER).  THE UNWANTED SIGNALS SECOND HARMONIC WILL FALL
JUST BELOW THE MARK TONE OF 2125 AND DESENSITIZE THE DEMODULATOR
CIRCUIT.  IT WILL ALSO BE APPARENT ON THE FREQUENCY DISPLAY WITH
VERY LOW OR NO AUDIO FEEDING THE AMT-1.
TO MAKE THE MOD, IS SIMPLE.  I HAVE A PHOTOCOPY FROM AEA OF THE
AMT-1 BOARD THAT SHOWS WHERE TO CUT ONE TRACE AND ADD ONE WIRE. I
DONT THINK IT WILL REPRODUCE SO IF IT IS NEEDED, IT WILL BE LOANED
OUT.  IT IS AN EASY FIX FOR A VERY SERIOUS PROBLEM.  ON THE ONE I
DID, IT WIPED THE UNWANTED SIGNAL OUT COMPLETELY.
CONTINUED IN FILE - AMT1.3