Motorola Radio Mcs2000 Vol 1 68p81083c20 A Manual

 
Radio Tuning Procedure6-9 
Select 5 Transmit 
Deviation
(GVN6011 only) 
This tuning sequence is ONLY for radios with Conventional 
Select 5 Signaling software being tuned with the RSS 
GVN6011. 
The Select 5 Deviation Softpot is used to tune the FFSK signaling deviation. 
Tuning is performed at one frequency and for 25 kHz channel spacing. The 
radio generates a Select 5 signal for tuning. Values for other frequencies and 
channel spacings are calculated by the radio software.
Alignment of the Transmit...

 
6-10Radio Tuning Procedure 
Rated Audio 
Alignment of the Rated Audio is not required on these radios. 
Front-End Pre-
Selector 
Alignment of the front-end pre-selector is not required on these radios. 

 
Controller Section Theory of Operation 7-1 
Controller Section
Theory of Operation 
7 
Introduction 
The radio is a microcontroller-based dual mode (trunked/conventional) 
transceiver. The microcontroller determines the active state of the radio 
(transmit/receive), monitors radio status, and processes operator commands 
entered from the keypad or the other radio controls.
In the Low and Mid Power versions of the radio all radio circuitry is contained 
on a single rigid printed circuit board (PCB). In...

 
7-2 Controller Section Theory of Operation 
The radio controller consists of 5 main functional sections. These are: 
¥ voltage regulation
¥ power control
¥ interfacing
¥ microprocessor operation
¥ audio and signalling processing
The controller is based on the Motorola 68HC11F1 microprocessor (U0103). 
In addition to the microprocessor, the controller has 3 external memory 
devices, signal MUX IC (U0105), and a Support Logic IC (SLIC IV, SLIC IVa, or 
SLIC V, U0104). The 3 memory devices consist of a 32...

 
Controller Section Theory of Operation 7-3  
UNSW 5V is only used in a few areas which draw low current and requires 5 V 
while the radio is off. 
Electronic On/Off 
Unlike older radios whose on/off feature was controlled only by the 
mechanical on/off switch, this radio has circuitry which allow radio software 
and/or external triggers to turn the radio on or off without direct user action. 
Some examples of this usage are 1) automatic turn on when emergency switch 
is engaged; 2) automatic turn on...

 
7-4 Controller Section Theory of Operation 
microprocessor has Þnished processing the emergency press, it sets the B+ 
CNTL output to a logic 0. This turns off Q0511 and the radio turns off. Notice 
that EMER TRIG also goes to U0104-D5 and U0003-F2. This is where the 
appropriate microprocessor is alerted to the emergency condition. If the radio 
was already on when emergency was triggered then B+ CTRL would already be 
high and EMER TRIG going high due to the emergency condition would have 
no effect...

 
Controller Section Theory of Operation 7-5  
Ignition input is active and sets the B+ CNTL output to a logic 1 to latch on 
SW B+. If the software determines that the radio should not be operating, it 
will set the CLEAR output to a logic 1 and the B+ CNTL output to a logic 0. 
This sets a latch composed of Q0514 - Q0517, R0519 and R0521. The latch 
output (at the collector of Q0517) will go to a logic 0 (at Q0517) and turn off 
Q0519, which allows R0514 to pull Q0511-4 high, switching the FET off. The...

 
7-6 Controller Section Theory of Operation 
*  The ÒDefault from FactoryÓ was changed in Release 4.01.
   Take special note of Emergency operation (shown in oversize  
bold  
 print) under these conditions.
à  For Þrmware versions older than Release 4.0, the feature will operate as shown in parenthesis. To deter-
mine Þrmware version present in radio, proceed as follows:
Within 10 Seconds after powering on the radio, press the test mode entry button Þve times. On Model I 
radio, test mode entry button...

 
Controller Section Theory of Operation 7-7  
The microprocessor controls K9.1 enable (K9.1 ENB) to bias the PA and 
antenna switch, PA disable (PA DIS) to disable the PA control voltage, and 
power range (PWR RANGE) to adjust the number of D/A steps per watt.
The Power Range Mode is not used on all models.
The ALC loop regulates power by adjusting the PA control line PA CNTL to 
keep the forward power voltage V FORWARD at a constant level. V FORWARD 
is ampliÞed with a gain of set by the PWR RANGE...

 
7-8 Controller Section Theory of Operation 
U0551 pin 13. The PA control voltage at U0550 pin 8 connects to opamp 
noninverting input U0202 pin 3 through the voltage divider formed by R0592 
and R0591 and lowpass capacitor C0572. Control voltage limit is set by the D/
A output PA CNTL LIM at U0551 pin 13 which connects to inverting input 
U0202 pin 2 through R0584, Q0556 and R0590. Transistor Q0556 is connected 
to the PA disable line, PA DIS which effectively pulls the control voltage limit 
to zero...