Ameritron arb 700 schematic

Ameritron ARB-700

Instruction Manual

INTRODUCTION

The ARB-700 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-700 places
less stress on the radio than the smallest isolation relay.

The ARB-700, when properly installed, fully protects radios from
damage caused by keying line transients or excessive current and
voltage. Any transceiver that provides as external power amplifier
control line may be used to control any amplifier having a relay control
voltage under 200 volts and 200 mA when the ARB-700 is used. The
ARB-700 fully protects transceivers like the Icom 706 from excessive
control line voltage or current, and even allows a simple and safe
interface to rigs like Ten-Tecs's or Yaesu's that source a positive
amplifier control voltage.

TECHNICAL DESCRIPTION

The ARB-700 draws only 1 mA per volt from a radio keying line that
goes high (common in Ten-Tec's). If the keying line goes to 12 volts,
the ARB-700 will draw 12 mA from the radio. Any radio pulling the
control line 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.

INSTALLATION

If your radio has a control line that pulls low:

1.) Connect the center pin of the jack marked "RADIO" to the radio's
amplifier control line. Connect the shell of the "RADIO" jack to the
radio's common control line connection or ground.

2.) Connect the center pin of the "POWER" jack to a positive supply
voltage. This voltage must be more than 3 volts but less than 30
volts for the maximum safe voltage for the radio. You can find the
voltage rating in the radio's manual, or ask the radio's manufacturer
what the safe control line voltage is. In nearly all cases, 5-12 volts
will be completely safe.

3.) Connect the center pin of the jack marked "AMP Relay" to the
amplifiers relay control jack. Do not exceed 200 volts or 200mA on
this jack, and not apply AC or negative voltage. Connect the shell
of this jack to the amplifier's relay control line ground.

If your radio has a control line that goes high to activate the
amplifier:

1.) Connect the center pin of the jack marked "RADIO" directly to the
shell of the "RADIO" jack.

2.) Connect the center pin of the "POWER" jack to the radio's positive
control voltage. This voltage must be more than 3 volts but less

than 30 volts.

3.) Connect the center pin of the jack marked "AMP Relay" to the
amplifier's relay control jack. Connect the shell of this jack to the
amplifiers relay control line ground.

Warning: Do not exceed 200 volts or 200 mA on AMP Relay jack,

and do not apply AC or negative voltage.

SCHEMATIC