The USAlert WatchDog LT is a 2-Tone voice pager developed
for use by fireman and other emergency personnel in the public safety markets. The LT can be used in any
radio system that requires tone alerting and channel monitoring. Available in VHF (138 MHz to 174 MHz)
or UHF (406 MHz to 512 MHz) frequency bands, the very loud and rugged WatchDog LT also features separate
receiver boards designed specifically for narrowband or wideband operation. This makes the LT pager not only
narrowband capable, but narrowband compliant.
The WatchDog LT is a simplified version of the original USAlert WatchDog voice pager. Along with being a more
compact and lightweight option to the WatchDog, the LT also operates with a 4-position function switch. Each
position can be individually programmed for the desired channel, alerting mode, monitoring mode, alerting type,
and type of scan. The LT has 4 minutes of stored voice capability and retains the messages when the pager is
powered off. The LT also holds a protection rating of IP66, which translates to protection against dust intrusion
and powerful water jets from any direction. Like the WatchDog pager, the LT comes standard with rechargeable
batteries, a battery charger, and a 2 year warranty. An extended 5 year warranty is optional. A
free 30 day demo unit is available upon request.
WATCHDOG LT PAGER CONTROLS AND FUNCTIONS
On / Off and Volume Control
The On / Off Volume Control is located on the top of the pager. Along with turning the pager on or off, the
control provides a continuous adjustment for the audio and alert levels, providing the alert is not programmed
to a maximum volume setting.
4-Position Function Switch
The four position function switch is located on the top of the pager in the center. Each position can be
individually programmed for the channel desired, selective call mode, monitor mode, alert type and type scan.
Reset Button
The reset button is located on the top of the pager and is typically used to reset the audio and put the pager
back into the standby mode. It can also be used to place the pager into the “quick monitor” or “audio lock
on” mode of operation. Depress the reset button and release in less than .75 seconds and the pager will
return to the standby mode. Press and hold for .75 but less than 1.5 seconds and the pager will enter
monitor mode. Press for more than 1.5 seconds and the audio will lock on and remain on continuously
until reset.
Front Control Buttons and Message Control
There are three buttons located on the front of the pager for voice memory message control. The right
button will initiate playback. The left and center buttons will allow selection of stored messages in
a forward or reverse direction. Message memory is 4 minutes and all messages are stored dynamically. Stored
messages are retained in memory even when the pager is powered off or the batteries removed. If no message
is stored the pager will emit a short beep.
Each time the right button is depressed, the last message stored will replay or repeat from the
beginning. Using the left or center button can change the message to be played once playback has
been initiated. Deleting messages is accomplished by depressing and holding down the top Reset
Button, then powering off the pager. All messages will be removed.
WatchDog LT Scan Operation
The WatchDog LT pager has three types of scan, “Priority Scan”, “Selective Call Scan”, and “Channel
Scan”. Scanning a two-channel LT is enabled by programming any of the 4-Position Function Switch
settings to the desired scan type.
If “Priority Scan” is enabled, the WatchDog LT pager will alternately search from frequency 1 (F1) to
frequency 2 (F2) looking for the presence of a carrier. Alerting can only occur on the priority
channel (F1). If channel activity is detected on (F2), the WatchDog LT pager will process voice on
(F2) and periodically scan back to (F1) looking for the presence of a carrier.
The “Selective Call Scan” mode allows the WatchDog LT to silently scan from channel to channel looking
for address tones. The pager will only open the audio path based on detection of an address and not
just channel activity. If a proper address is detected, the LT will alert and open the audio path for messaging.
“Channel Scan” mode will alternately search from (F1) to (F2) looking for the presence of carrier. The
primary function of “Channel Scan” is to allow monitoring any activity on either channel. Only one channel
can be actively monitored at a time and no alerting can occur on either channel.