WKW-7 Power Adapter

NSN: 6150-01-435-3919
Brooke Clarke 2013
WKW-7 Power Adapter
    Input Cable Wiring
    Printed Circuit Board


This is a combined battery box, battery and battery eliminator and battery charger for the lead acid BB-490.  It can be used with the PSC-5, PRC-113, PRC-138 and URC-200 transceivers.
It contains a single BB-490 Lead Acid battery in the BA-5590 form factor.  This battery is probably dead even though this is a new in the box power adapter.
This came in factory packaging and was New Old Stock (NOS).

Note that the charger is designed for the BB-490 lead acid chemistry and since the BB-490 is obsolete this adapter is no longer useful.  A possible fix would be to use the 5590BA battery adapter filled with lead acid cells to simulate the BB-490.  I haven't tried this so don't know if the cells will fit.

The main unit at the top.
DC cord at lower left.
2 gell cell batteries added by Mike Murphy at right.
WKW-7 Power Adapter


On one end of the battery box there are:
Radio latch
top LED - battery charge indicator (off when transmitting)
bottom green LED - DC Input Power LED
Small connector - Auxiliary output for KY-57, KY-99 etc.
Large connector - DC input
box vent


NSN: 6150-01-435-3919 is the unit on this page which I think only accepts DC inputs (not the world AC input) available from Mike Murphy
NSN: 6150-01-435-3917 is a shock mount for the radio
NSN: 6130-01-508-4877 is ther MRC-92 World Voltage AC/DC version. https://www.ultralifecorporation.com/PrivateDocuments/TDS_MRC-92.pdf, MRC-92


The problem is that the BB-490 battery that came with the wKW-7 is dead and obsolete.  It's a bad idea to substitute another battery chemistry (more modern battery like a BB-390, BB-590 or BB-2590 since the battery charger may explode them).

To see if the BB-490 will take a charge I've connected the DC input and am letting it sit for a day or so.

As  you can see the initial current draw is 0.019 amps.
The BB-490 is not taking a charge.
After 15 minutes it's up to 23 milliamps
which is a good sign that it might charge.
WKW-7 Power Adapter Atempt at Charging BB-490 two 1.3 AH Gel cells - not enough room to fit inside.
but close enough to work in the WKW-7.
BB-490 & two 1.3 AH Gel cell batteries
Using as a Battery Eliminator with RT-1319/PRC-138
                  & WKW-7 Power Supply as Battery Eliminator

Input Cable Wiring

The 5 pin input connector looks very much like the one on the M455-1 that can be wired for either AC or DC inputs. 
The supplied cable is for DC inputs between 11 and 36 VDC, i.e for either a 12 Volt or 24 Volt vehicle electrical system.
There is a sticker on the side of the battery box (see photo at top of this page) that says you can also use an AC input
between 95 and 260 VAC at 47 to 440 Hz.  But the schematic in the manual does not show an AC supply and only the red and black wires for the DC input are on J1.

J1 Pin
DC Ground
DC In (red)

Printed Circuit Board

By removing 10 screws and 2 connector nuts the PCB can be removed.

Only the red and black wires come from the input connector J1,
so the only allowed input is the 11 - 36 VDC.
There is no AC input.

Aux Out conn: 851-07A8-2S A:+, B:-

J1 input conn: PT07A-14-5P

IC: MC33074AP
WKW-7 Power Adapter PCB


Battery Chargers
BA-5590 Family of military batteries - 5590BA Battery Adapter
BA-5590 Family Battery Eliminators


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Page created 24 April 2013.