
MFJ-269D Instruction Manual LF/HF/VHF/UHF SWR Analyzer
5
WARNING: REVERSE POLARITY OR EXCESSIVE VOLTAGE CAN DAMAGE OR DESTROY THE
MFJ-269D. NEVER APPLY MORE THAN 18 VOLTS, NEVER USE AC OR POSITIVE
GROUND SUPPLIES! NEVER ADD OR REMOVE BATTERIES WITH AN EXTERNAL
POWER SUPPLY CONNECTED TO THIS UNIT, OR WITH THE POWER SWITCH ON.
2.2
Internal Batteries
When installing internal batteries,
first check the position of a small black-plastic internal jumper plug
that controls charger operation. The jumper is located inside the unit at the top of the printed circuit
board near the area of the OFF-ON switch and power connector.
To access it, remove all eight screws
on the sides of the case and remove the back cover. The black plastic jumper fits over two of three
adjacent pins (see detailed instructions below). The plug must be properly positioned for the type of cell
you plan to use (AA rechargeable or AA non-rechargeable).
2.3
Rechargeable Batteries
Important Note:
When using rechargeable batteries, your external power source must deliver at least 14
volts. If supply voltage is too low, the charger can't function and batteries will eventually discharge. If
batteries are depleted, charge with the analyzer power switch turned off -- it may take ten hours or more
to fully restore depleted cells.
Important Warning:
Never change batteries with the power switch "On" or with an external supply
plugged in -- permanent damage may result. Always remove batteries when shipping the analyzer or
storing it for an extended period (more than a month).
When using rechargeable batteries,
the internal black plastic jumper must be set to the proper position
.
Remove the analyzer cover and locate the jumper on the pc board (near the power jack). Confirm that it
is set correctly. If not, reposition as shown below:
Again, when the
Charger Jumper
is
ON
and a 13.8 to 18 volt source is applied, the charger will be
functional. Typical charging current is 10-20 mA.
2.4
Using Conventional “AA” Dry Cell Batteries
When using
non-reachable batteries
, install only high quality alkaline cells in matched sets (same
manufacturer and date code). Conventional zinc-based cells have a shorter shelf and service life, and they
are also more prone to leakage. Also, to prevent leakage,
remove weak alkaline batteries immediately
.
WARNING: WHEN USING NON-RECHARGEABLE BATTERIES, THE CHARGING SYSTEM MUST
BE DEFEATED! IF YOU FAIL TO FOLLOW THIS WARNING, THE BATTERIES WILL
LIKELY LEAK AND RUIN THE ANALYZER!
When using
non-rechargeable batteries
, set the internal jumper as shown below: