User's Manual

2-11
2-5. OPERATING PROCEDURE
2.5.1 SITING
The transceiver operates in the VHF and UHF frequency bands, these are Line-Of Sight
(LOS) frequencies; therefore, siting of the transceiver
greatly affects its operating range. The
longest range is normally obtained when a direct LOS is maintained between the transceivers.
Use of hilltop or tower locations will increase the LOS range. Location in valleys with intervening
hills, behind buildings or in dense woods may reduce or
prevent communications. If possible,
avoid locations near electrical interference sources, such as power and telephone lines, radars,
welders and electrical generators.
2-5.1. UNENCRYPTED OPERATION
The following procedure allows unencrypted operation.
1.
Attach the VHF/UHF antenna and H-189/GR handset to the transceiver.
2. Turn the transceiver on by rotating the VOL control clockwise.
3. Set the transceiver PT.
4.
Set the SQ control to OFF and set the VOL control until noise is heard from the
handset or the loudspeaker If enabled per Paragraph 2-3.1.4).
5. Select operating modes and frequencies per Paragraph 2-3.
6. To transmit, hold the H-189/GR handset Push-To-Talk (PTT) switch down while
talking into the mouthpiece.
7. To receive, release the PTT switch and listen to the handset earpiece or to the
loudspeaker.
8. To eliminate the background noise when no receive signal is present, turn the SQ
control clockwise just until the noise turns off. Adjusting the control further clockwise
reduces the sensitivity of the squelch-break.
2-6. URC-200 (V2) EEPROM LIMITATIONS
The URC-200 (V2) transceivers use
the Freescale MC9S08DN60AMLH microprocessor for
control and interface operations of the transceiver. The
processor has 2048 bytes of internal
EEPROM that is capable of storing data after the power has been turned off. The EEPROM's
write cycle (an erase followed by a write) is only guaranteed for 100,000 operations. However,
typical operational life at ambient temperatures (approximately +25C) is much greater.
Excessive use of the following commands will result in a reduction in the EEPROM's write
cycle.
2-6.1. FRONT PANEL USER COMMAND LIMITATIONS
The following front panel user commands should be used only as needed.
2-6.1.1 Select Scan Channels
When a preset channel is selected or deselected for the scan list, the preset channel data is
updated. Repeated use of this
command may result in defective channel data. (Reference:
Paragraph 2-3.2.7 and Table 3-3, "C" code.
2-6.1.2 Cancellation of Presets
This command is used to initialize all channels
to a default configuration (AM, low power,
225 MHz receive and transmit, PT, wideband, and off scan list). (Reference: Paragraph 2-3.1.2
and Table 3-3, "I" code.
2-6.1.3 Select Preset Channels
This command changes the currently selected preset and updates the current preset
channel number in
the EEPROM. Excessive use of this command may result in the transceiver