Ameritron arb 702i2 schematic

Ameritron ARB-702I2

Instruction Manual

INTRODUCTION

The ARB-702I2 serves the same function as the isolation relay recommended by
many transceiver manufacturers, but has no moving parts to wear out or reduce
T/R switching speed. The ARB-702I2 places less stress on the radio than the
smallest isolation relay.

The ARB-702I2, when properly installed, fully protects radios from damage
caused by keying line transients or excessive current and voltage. Any
transceiver that provides an external power amplifier control line may be used to
control any amplifier having a positive relay control voltage under 200 volts and
200 mA when the ARB-702I2 is used. The ARB-702I2 fully protects
transceivers like the Icom 706 from excessive control line voltage or current, and
even allows a simple and safe interface to rigs that source a positive amplifier
control voltage.

The ARB-702I2 has a 13 pin plug to match the Icom 706 and Mark II. If the
transceiver is not the Icom 706 or Mark II, then check with manufacture for the
installation.

TECHNICAL DESCRIPTION

The ARB-702I2 draws only 1 mA per volt from a radio keying line that goes
high. If the keying line goes to 12 volts, the ARB-702 will draw 12 mA from the
radio. Any radio pulling the control line low will have less than 2 mA of current.
The open circuit voltage applied to the radio can be set by the user to any
voltage between 3 and 30 volts.

The output will pull a 100 mA relay line to within 0.2 volts of ground, and is
capable of handling 200 volts of positive open circuit voltage.

The ARB-702I2's 13 pin plug has the supply voltage, relay, and ALC
connections to properly operate the ARB-720I2 and amplifier when connected to
the Icom 706 and Mark II.

INSTALLATION

1.) Plug the ARB-702I2's 13 pin cable into the Icom's ACC socket.

2.) Connect a RCA phono cable from the Amp Relay jack on the ARB-702I2 to
the amplifier's relay line.

WarningWarning:: Amplifier's relay must not exceed 200 volts orAmplifier's relay must not exceed 200 volts or

200 mA ! Do not apply negative or AC voltage to200 mA ! Do not apply negative or AC voltage to
the ARB-702i2 !the ARB-702i2 !

3.) If using an ALC, connect a RCA phono cable from ALC connector on the
ARB-702I2 to ALC of the amplifier.

SCHEMATIC