MFJ MFJ-4114, MFJ-4114X User Manual

MFJ-4114 PORTABLE RECHARGEABLE POW ER PACK

GENERAL DESCRIPTION: The MFJ-4114 powers MFJ QRP-series transceivers
from either AC mains or self-contained rechargeable NiCd batteries.
Front-panel switching selects AC or BATTERY operation and controls
operation of th e buil t- in cons tant-current charger. Attractively
styled to match MFJ transceivers, the MFJ4114 is also compatible with
any other device requiring 13.8 Volts at up to 1.2 Amps. Output
voltage is supplied to a coaxial power jack or color-code d binding
posts on the back panel.

SPECIFICATIONS:

A C Supply Output: 13.8 VDC @ 1.2 A, Voltage Regulated.
Charger Output: 100 mA all loads, Current Regulated. NiCd
Battery Pack Output: 13-15 VDC @ 1.2 A NiCd Storage
Capacity: 1.6 AH - 4.0 AH Charge Time: 14-hours typical
for 1.6 AH NiCds. Batteries: NiCd "D" Cells (12
required). Size: 6" x 6 " x 3.5"

Weight: Approx. 3 Lbs.

THEOR Y OF OPERATION (see schematic diagram): An external wall
transformer (MFJ -407-1106) provides AC to bridge rectifier.
Bridge output (approx. 20 VDC) is Filtered by a 4400-uF capacitor
bank and routed to power pack regulators. Three 1N4001 diodes
bootstrap the LM7812 supply regulator to 13.8 V output. The charger
regulator (LM317T) i s configured as a constant- current source set at
100 mA by a 10-Ohm series resistor. LED's indicate when the MFJ-4114
is powered and when the cha r ger circuit is online. DPDT switching
selects AC or BATTERY as the power source, and turns the CHARGE
circuit on or off when AC is in use.

BATTERY INSTALLATION: The MFJ-4114 lets you choose the best NiCds
for your application. For normal operation, 1.6-AH cells like Radio
Sha ck 23-123, Duracell NC13, Eveready CH50, or GE G C3 are good
choices. Heavy-duty 4.0 AH cells like the Radio Shack 23-140 provide
a significantly longer discharge cycle.

To install NiCd s, remove 8 screws ringing the bottom of the MFJ4114
case (se e Fi g u r e 1). T h e bottom plate drops out and provides holders
for 8 cells; the remaining 4 install next to the pc board in th e top.
Charge new batteries fully before using to power equipment (14-hour
charge cycle typical for 1.6 AH NiCds).

NOTE: The MFJ-4114 is specifically designed for NiCds. If you must
use conventional batteries, install no more than 1 0 c e ll s and jumper
the remaining 2 positions in the batte ry holder with a cliplead.
NEVER ATTEMPT TO RECHARGE ALKALINE OR CARBON-ZINC CELLS!

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INSTALLING YOUR POWER PACK: The MFJ-4114 power pack may be s tacked

g

ging

with a companion MFJ transceiv er a nd tuner. Two bra ckets and 8
screws are inc luded i n this packag e to co nnect the power pack to the
MFJ transceiver and tuner.

CONTROLS:

1. POWER
AC/BAT Switch: Select AC or NiCds as power source.

2. AC: Red LED indicates when AC is supplied to MFJ-4114. 3.
CHG: Green LED indicates when Charger is on-line.

4. CHARGER Switch: Turns charger ON or OFF when is AC conn ected.

OPERATION:

1. TO CHARGE NiCds: Insert the molded plug from the MFJ-4 07-1106 AC
adapter into the header connector on rear of the MFJ-4114 powe r
pack. Plug t he A C adapte r in to AC m ains. The red A C LED on panel
will light . Pre ss POWE R swi tch to A C, and pres s CHAR GE s witch to
ON. The green CHG LED on the p anel will light.

NOTE: For best battery life, always press CHARGE switch OF F at the
end of the charge period (prevents over chargi ng NiC d cells).

2. TO OPERATE TRANSCEIVER FROM AC POWER: Connect AC adapte r to the
MFJ-4114. Connect your transce iver to the MFJ- 4 114 power j a ck
usin g a p a tc h c o rd ( 5. 5m m OD , 2. 1m m ID ) . Y ou ma y al s o c onnect
auxiliary equipme nt to the red and black bin din g-p ost power
terminals (Red = +, Blk = Gnd). Press POWER switch to ON.

3. TO OPERATE TRANS CEIVER FR OM NiCd PACK: Con nect tran sceiver as
above. Remov e AC wall ad apte r. Pres s POW ER sw itch to BAT .

IMPORTANT NOTE: If you operate from BAT with the AC adapter
plugged in, the CHG light still functions -- but the charger circuit
is totally disconnected from t he p ack. When ope rati ng on BAT,
unplug the AC adapter to disable the CHG light and prevent
confusion.

CARE AND FEEDING OF NiCds (for deepest cyc le and longest life) :

1. Charge NiCds fully prior to first use .

2. Always discharge to 11 VDC (or erratic radio operation).

3. Always recharge for full 100 mA period specified on cell.

4. Never dischar

5. Avoid rechar

e totally (below 10 V).

mid-cycle.

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