Portable / Mobile Switch; Mod Audio/Audio Tap In / Off / Mic Audio Switch; On Hook / Off Hook Switch; Operation - Tait TM9100 Service Manual

24.2

Operation

24.2.1

Portable / Mobile Switch

24.2.2

Mod Audio/Audio Tap In / Off / Mic Audio Switch

24.2.3

On Hook / Off Hook Switch

TM9100 Service Manual
© Tait Electronics Limited August 2005
This section explains the function of the TOPA-SV-024 test unit
controls. The procedure for using the test unit is described in the relevant
section on test equipment setup.
This 2-way toggle switch is used to switch attenuation resistors (R4, R5,
R6) in and out of the line from the radio's positive speaker output to the
positive receive audio/SINAD output of the test unit (before the isolating
transformer).
When set to Portable, the attenuation resistors are switched out.
When set to Mobile, the attenuation resistors are switched in
(attenuation 10:1).
Important
Selecting the wrong switch position may result in
incorrect SINAD readings and damage to the test unit.
This 3-way toggle switch is used to switch between Mod Audio/Audio
Tap In, Mic Audio, and Off (no audio signal).
With the Tait Orca portables, this switch can be used for setting up
dual point modulation by applying modulation to different parts of
the radio.
For normal transmit deviation tests (other portables and mobiles), this
switch is set to Mic Audio.
Important When using the test unit with portables, the On Hook /
Off Hook toggle switch must be set to Off Hook.
Portables do not have a hookswitch, and if the switch is
set to On Hook, the accessory function key of the
portable is activated.
This 2-way toggle switch is used to simulate the microphone hookswitch
opening ("hook off") and closing ("hook on"). This is done by
switching a 12kΩ resistor (R3) in or out of the MIC_PTT line.
When set to Off Hook, the 12kΩ resistor (R3) is switched out of the
MIC_PTT line. This simulates the microphone being removed from
the microphone clip.
When set to On Hook, a 12kΩ resistor (R3) is switched into the
MIC_PTT line. This simulates the microphone being placed on the
microphone clip.
TOPA-SV-024 Test Unit 479