Ericsson LBI-38848D manual Accessories and Options

LBI-38848D

Table 2 - Digital Channel Guard Codes

PRIMARY	EQUIVALENT			PRIMARY	EQUIVALENT				PRIMARY	EQUIVALENT
CODE	CODE			CODE	CODE				CODE	CODE
023	340	766		251	236	704	742		632	123	657
025				261	227	567			565	307	362
026	566			263	213	736			654	163	460	607
031	374	643		265	171	426			662	363	436	443	444
032				271	427	510	762		664	344	471	715
043	355			306	147	303	761		703	150	256
047	375	707		311	330	456	561		712	136	502
051	520	771		315	321	673			723	235	611	671
054	405	675		331	372	507			731	447	473	474	744
065	301			343	324	570			732	164	207
071	603	717	746	346	616	635	724		734	066
072	470	701		351	353	435			743	312	515	663
073	640			364	130	641			754	076	203
074	360	721		365	107				036	137
114	327	615		371	217	453	530		053
115	534	674		411	117	756			122	535
116	060	737		412	127	441	711		145	525
125	173			413	133	620			212	253
131	572	702		423	234	563	621	713	225	536
132	605	634	714	431	262	316	730		246	542	653
134	273			432	276	326			252	661
143	333			445	222	457	575		255	425
152	366	415		464	237	642	772		266	655
155	233	660		465	056	656			274	652
156	517	741		466	144	666			325	550	626
162	416	553		503	157	322			332	433	552
165	354			506	224	313	574		356	521
172	057			516	067	720			446	467	511	672
174	142	270		532	161	345			452	524	765
205	135	610		546	317	614	751		454	513	545	564
223	350	475	750	606	153	630			455	533	551
226	104	557		612	254	314	706		462	472	623	725
243	267	342		624	075	501			523	647	726
244	176	417		627	037	560			526	562	645
245	370	554		631	231	504	636	745

NOTE:

Primary codes in bold are unique Ericsson codes.

AUDIO/LOGIC BOARD

The Audio/Logic Board provides all audio and digital processing of the receive and transmit audio for digital processing by the Logic Board. The board also contains audio filtering, conventional analog tone processing, and the receiver squelch. The Audio/Logic Board controls the opera- tion of the radio and digitally processes the receive and transmit audio. The board contains a microprocessor and associated memory circuits including an EPROM for con- trolling the processor and a programmable "personality" memory (an Electrically Erasable PROM - EEPROM) to store customer frequencies, tones and options. The micro- processor provides control data to the Audio Signal Proces- sor (ASP), conventional tone generation and detection, frequency data for the synthesizer, and sends and receives data to another microprocessor on the Display Board for the LCD.

SYSTEM BOARD

The system board controls the main input power to the radio. IGNITION SENSE input lead provides the necessary signals to the MOSFET switching circuit. The board also interfaces all option connections from the internal boards in the radio with the optional items outside of the radio. All external options for the radio, interconnect to the System Board through the back of the radio using an optional cable.

FRONT CAP ASSEMBLY

The Front Cap Assembly contains the Audio Amplifier Board. The Audio Amplifier Board provides compression of the microphone audio. It also provides audio compression for the received audio in the discriminator and internal/ex- ternal speaker audio paths. A 10-watt power amplifier is provided on the board to drive a 4-ohm internal/external speaker.

ACCESSORIES AND OPTIONS

PC PROGRAMMER OPTIONS

The radio is programmed using an IBM compatible personal computer equipped with a RS-232 port. Option TQ3370 provides the RS-232 serial interface unit and the cable between the PC and the unit. An auxiliary power supply for the unit is also included but is not needed to program the radio.

Option TQ3372 provides the radio programming cable between the PC interface unit and the radio microphone jack. MDX PC programming software Option TQ3346 (GE- MARC only) or TQ3373 (EDACS) is provided in both 3.5 and 5.25 inch diskettes.

PC PROGRAMMED OPTIONS

Carrier Control Timer (CCT)

The Carrier Control Timer turns off the transmitter after the microphone push-to-talk (PTT) switch has been keyed for a pre-programmed time period. A pulsing alert tone warns the operator to unkey and then rekey the PTT to continue the transmission. The timer can be programmed, using the PC programmer. Any time periods between 30 seconds and 7.5 minutes can be programmed in 30 second increments. The timer can be enabled or disabled for each channel.

Channel Guard

Channel Guard provides a means of restricting calls to specific radios through the use of a Continuous Tone Coded Squelch System (CTCSS), or a Continuous Digital Coded Squelch System (CDCSS). Tone frequencies range from

67.0Hz to 210.7 Hz in 0.1 Hz steps. There are 83 standard PC programmable digital codes. The Channel Guard tone frequencies and codes are software programmable. Both tone frequencies and digital codes may be used. These codes and frequencies are listed in Table 1 - Channel Guard Tone Frequencies and Table 2 - Digital Channel Guard Codes.

NOTE

To reverse the polarity of the digital Channel Guard codes in the PC programmer, type I ("inverted") before the code number, i.e. I023.

Squelch Tail Elimination (STE)

STE is used with tone and digital Channel Guard to eliminate squelch tails. The STE burst is transmitted when the microphone PTT is released. The receiving radio decodes the burst and mutes the receiver audio for 250ms. This mute time allows the transmission to end and to mute the squelch tail. The radio looks for STE on the received signal when the microphone is either on or off-hook. The STE is enabled for transmit and/or receive by PC programming the radio’s per- sonality.

Retry Option

If no channel is free, the radio can be programmed to activate the Call Retry state and display ’RETRYING’ in the display. Retrying causes the radio to revert to Idle mode and scan for an incoming call while trying to acquire a free repeater approximately every 5 seconds for a 2 minute pe- riod.

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