Tait TM8100 mobiles, Service Manual

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616 TOPA-SV-024 Test Unit TM8100/TM8200 Service Manual
© Tait Electronics Limited November 2007
38.2.4 Rx / Tx/PTT Switch
This 2-way toggle switch is used to switch between receive and transmit mode.
■
When set to
Rx
, the PTT line is switched to high impedance.
■
When set to
Tx/PTT
, the PTT line is pulled to ground.
38.2.5 Speaker / Radio / Load Switch
This 3-way toggle switch is used during receive audio tests to switch the audio
to the test unit speaker (
Speaker
), to the radio’s internal speaker (
Radio
) or to
a dummy load consisting of R1 and R2 (
Load
).
Note
This switch does not disconnect the radio’s internal speaker on
mobiles. If the switch is set to
Speaker
or
Load
, this simulates an
external speaker being connected in parallel to the radio’s internal
speaker.
With all settings, a low level audio signal is available for testing through
the SINAD port.
Portable
■
When set to
Speaker
, only the speaker of the test unit is active.
■
When set to
Radio
, only the speaker of the portable is active.
■
When set to
Load
, no speaker is active. The audio signal is terminated in
the test unit dummy load.
Mobile ■
When set to
Speaker
, the speakers of the test unit and the mobile are
both active. The speaker of the mobile cannot be disconnected.
■
When set to
Radio
, only the speaker of the mobile is active.
■
When set to
Load
, the speaker of the mobile remains active.