ID-O-Matic II Manual
02/27/2010
Page 6 of 14
J1-7
COR input. Normally used for a COR or squelch signal from the
receiver. This signal was known as START on the original ID-O-
Matic.
J1-8
Receiver audio input.
J1-9
INHIBIT input. Can be used to hold off ID if needed.
J1-10
Audio output. For HT use, the PTT signal is supplied through a 2.2K
Ohm resistor. *Note: See “Fixing R10”, below.
Connecting to your equipment
PTT and CW Outputs:
The PTT and CW outputs are open-drain MOSFET outputs, and can be directly connected to inputs that
do not exceed 60V or 200 mA at any time. They can be used to drive relatively low current relays if
needed. If you intend to use the ID-O-Matic II with equipment requiring grid-block or cathode keying or
any other application that will exceed 60 Volts or 200 mA, you will need to add a grid-block keying
adapter such as the Universal Keying Adapter 2 or some other suitable output arrangement.
Note that the CW output is an on/off keyed signal suitable for driving a CW transmitter, indicator or other
on/off keyed load. It is not an audio output.
Audio Signals:
The ID-O-Matic II uses two audio signal sources. The first is the Morse ID audio, also used for the
courtesy beep tone. This signal is generated as a pulse-width modulated (PWM) signal by the
microcontroller. After low-pass filtering provided by R9 & C3, it is passed to the LM386 audio amp.
Level control is provided by the ID_VOL trim pot.
The other source is the receiver audio input from J1-8. This signal is passed through the IN_VOL level
control and the de-emphasis circuit (R14/C12), then on to the LM386 amplifier. The two audio signals
are mixed and sent to J1-10 through a DC blocking capacitor.
COR and INHIBIT Signal Inputs:
Two control signal inputs, COR and INHIBIT, are used only in repeater mode. These inputs can be either
active-high or active-low. Active-high means that, when the signal is inactive, it is held at or near ground
potential. When it goes active, it should swing to a positive voltage of 3.5V or more. Conversely, active-
low means that the signal normally floats or is driven to some positive voltage, and goes to ground or near
ground when active. One example of this would be a grounding PTT switch or a relay input. For either
arrangement, the input signal conditioning circuits (R7/R12/D1/Q6 and R6/R13/D2/Q5) will clamp the
signals to safe levels of 4.7V or less, and invert them if necessary.
You will need to set the two jumpers according to the polarity of the input signals. Please note: this
version of the PCB has the polarity markings for the COR and INH inputs reversed. For an active-high
signal, set the corresponding jumper to the “L” position. For an active-low signal, set the jumper to the
“H” position. If either signal will not be used, leave the jumper off or (preferably) just leave it on the
center pin in case you need it later. In the following diagram, the jumpers are set for an active-high COR