27
TOPA-SV-024 Test Unit
Tuneup
August 2004
© Tait Electronics Ltd
2.2.4
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.
2.2.5
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
M8100 radios with a user interface. If the switch is set to
Speaker
or
Load
, this simulates an external speaker being connected in par-
allel to the radio’s internal speaker. TM8200 radios without a user
interface do not have an internal speaker.
With all settings, a low level audio signal is available for testing through
the SINAD port.
Tait Orca portables
■
When set to
Speaker
, only the speaker of the test unit is active.
■
When set to
Radio
, only the speaker of the Tait Orca portable is active.
■
When set to
Load
, no speaker is active. The audio signal is terminated in
the test unit dummy load.
TM8200 radios with
user interface
■
When set to
Speaker
, the speakers of the test unit and the TM8200 are
both active. The speaker of the TM8200 cannot be disconnected.
■
When set to
Radio
, only the speaker of the TM8200 is active.
■
When set to
Load
, the TM8200 speaker remains active.
