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DC Power Supply
An external DC power supply between 5 and 6 V supplying 1A can be
connected to the LT51 for power during normal operations and to charge the
NiMH Battery. The DC supply can be powered by a wall plug-pack from AC
mains or an appropriately configured Car battery adaptor. Plug the DC cord into
the LT51 DC connector.
NOTE: Use of the external charger for normal measurements will increase the
noise floor of spectrum measurements.
Charging
The battery must be charged on a regular basis. You can typically use the LT51
for up to 8 hours between charges. The time between charges may be reduced if
you use the backlight frequently, use large Tx output levels for extended time
intervals, or if you work in very cold weather. Charging time is approximately 6
hours for 2100mAh cells. When the battery is charging, the Red charging LED
illuminates. When charging is complete, the Red LED goes off, and the Green
DC LED will illuminate.
Level of Charge
The battery icon in the upper right of every screen indicates the battery charge.
Four black bars in the icon indicate full charge. Zero black bars indicate the
battery is very low and should be charged immediately. A warning screen
appears when there is a critical amount of charge left. Charging efficiency is best
with a temperature between 10°C (50°F) and 30°C (86° F).
LT51 User Manual
WARNING: Do not charge Alkaline cells, as there is no
protection against accidental charging.
WARNING: The batteries should only be charged when the
battery indicator shows 2 or less black bars (preferably when
only 1 bar is showing). Charging the batteries when 4 bars are
showing may damage the batteries and the LT51.
WARNING: Do not charge the batteries at temps below
0°C (32°F) or above 40°C (104° F).
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