Service manual

OPERATION
3-15
April 2001
Part No. 001-9800-203
occurs, the return time warning tone sounds to indicate
that time-out is approaching.
One use of this feature is to prevent a repeater
from being kept busy for an extended period by an
accidentally keyed transmitter. It can also prevent
possible damage to the transmitter caused by transmit-
ting for an excessively long period.
Penalty Timer
There is also a penalty timer that can be
programmed. If the time-out timer disables the trans-
mitter, this timer prevents the transmitter from being
keyed again for the programmed time. This prevents a
user from simply releasing the PTT switch and
pressing it again to continue a call. This timer can be
programmed for 0-60 seconds in 1-second steps. It is
available with all models, and starts when the PTT
switch is released. If the PTT switch is pressed during
the penalty time, the time-out indication occurs again.
3.5.17 TONE SELECT
If the TONES menu parameter is enabled by
programming (high tier models only), the user can
select the tones that sound. Otherwise, the tone mode
is selected by programming. The following choices are
available:
SILENT - All tones are disabled.
KEY BEEP - Only the Select switch (low tier models
only) and key press tones are enabled.
ALERT - All tones except the preceding Key Beep
tones are enabled.
ALL TONE - Both the preceding Key Beep and Alert
tones are enabled.
3.5.18 TRANSMITTER THERMAL FOLDBACK
The temperature of the power amplifier is moni-
tored by the control logic when transmitting. If a
temperature is detected that could damage the power
amplifier module or other devices, power is automati-
cally cut back to a preset low level. After sufficient
cooling occurs, power output returns to the normal
level. This provides hysteresis so that power is not cut
back again after only a short transmission. With the
low tier models, there is no indication that power is cut
back. With high tier models, the transmit LED is
orange instead of red (no message is displayed).
If temperature continues to increase at the low
power setting to the point where more serious damage
could occur (this should seldom happen), the trans-
mitter is disabled, a warning tone sounds, and “NO
POWER” is displayed (high tier models only). The
transmitter remains disabled until temperature
decreases to the first temperature limit. Power output
is then produced at the preset low setting. The temper-
ature limits and low power level are fixed in software.
The supply voltage applied the transceiver is also
monitored in the transmit mode. If this voltage rises
above 18.5 volts DC, the transmitter is disabled and
the same indications are produced as described in the
preceding paragraph. This prevents possible damage to
transistors in the transmitter.
3.6 OPTION SWITCHES AND MENU MODE
3.6.1 USING OPTION SWITCHES
The option switch availability for the various
models is as follows. If a function is controlled by an
option switch, it is not available as a menu function
and vice versa (high tier models only). Any switch can
also be disabled if desired. Descriptions of switch
functions start with Section 3.6.9.
Low Tier Models
- Four option switches are available
(see Figure 3-1). The top two have fixed functions
(SCAN and A/D) and the bottom two (AUX1 and
AUX2) are programmable for the functions listed in
Table 3-2.
High Tier Models
- Five option switches are available
(see Figure 3-2) and all are programmable for any of
the functions listed in Table 3-2. A key cap kit is
supplied with the transceiver that contains key caps
with labels for all available functions.
3.6.2 USING MENU MODE
NOTE: The menu mode is not available with low tier
models. Therefore, menu functions are either fixed in a
default condition by programming or not available.
The menu mode is selected by pressing the FCN
option switch twice within 8 seconds. If this switch has
been disabled or is not programmed, the menu mode is
not available. The functions that can be controlled by
the menu mode are indicated in the “Menu Items”