Speaker; Electrostatic Transient Protection; Passport Trunking Controller Board (Ptcb) - Motorola CDM1550 LS+ Detailed Service Manual

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Theory of Operation 2-35
Q0841 is switched on causing a low at IJP port PA 1. When the HOOK switch is closed, signal HOOK
is pulled to ground level. This switches off R0841 and the resulting high level at IJP port PA 1 informs
the IJP about the closed hang up switch. The IJP informs the host radio about any status change on
the HOOK line via SBEP bus.
2.1 0.9 Speaker
The control head contains a speaker for the receiver audio. The receiver audio signal from the
differential audio output of the audio amplifier located on the radio's controller is fed via connector
J0801-10 , -11 to the speaker connector P0801, pins 1 and 2. The speaker is connected to the
speaker connector P0801. The control head speaker can only be disconnected if an external
speaker, connected on the accessory connector, is used.
2.1 0.10 Electrostatic Transient Protection
2.11
Electrostatic transient protection is provided for sensitive components in the control head by diodes
VR0811 VR00812 and VR0816- VR0817 . The diodes limit any transient voltages. The associated
capacitors provide radio frequency interference (RFI) protection .
PassPort Trunking Controller Board (PTCB)
PassPort is an enhanced trunking protocol developed by Trident Microsystems that supports wide
area dispatch networking. A network is formed by linking several trunked sites together to form a
single system. This offers users an extended communication coverage area . Additionally, users with
PassPort can seamlessly roam among all sites within the network. Seamless roaming means that
the radio user does not have to manually change the position on the radio when roaming from site-
to-site. For models which feature PassPort Trunking operation, the PassPort Trunking Controller
Board is added to the top cover of the radio. This board also provides advanced voice storage
features . Refer to Figures 2-2, 2-3, and 2-5 for connector and signal routing from and to the radio
and PTCB. The PTCB is a non-servicable board and should be replaced if defective. The schematic
and circuit board details are included in this manual for informational purposes only.