HISTORY:
This component has been pulled from a very nice (fully functioning) KEPCO BOP 50-8M!
Why “part out” the KEPCO? I have decided to make this equipment an “organ donor” because I have had it advertised elsewhere as a fully functional unit but no interest, too “high brow” I guess.
Additionally it is VERY HEAVY (this is a FULL rack size unit, approaching 40Kg when it was packed) and I noticed light damage to the steel casing as well (scrape marks due to moving it around over the years).
Originally we acquired this equipment from an international R & D laboratory and used it ourselves for various test and research tasks, although the BOP range of Bi-polar power supplies can undertake many other tasks.
In brief, the KEPCO BOP 50-8M is a Bi-polar power supply providing 0-50V dual supplies at up to 8A current each.
But to be more specific it is much more than a Bi-polar power supply, the unit contains two high speed, high power Op amps and NO capacitors on the output (which can effect the frequency response/speed). The Op amps can operate up to 24Khz (resistive loads) with Ultra low noise, Ultra low ripple and they are MIL spec compliant.
The power Op amps are four quadrant, bi-polar operation with full control of the voltage and current on each channel via the front panel controls OR remote control/programming.
This KEPCO BOP 50-8M is not a “spring chicken”, date of manufacture was in the late 1990’s – not used very often but when it was called upon, it never missed a beat.

KEPCO designs and manufactures some wonderful professional laboratory and industrial power test equipment, take a look HERE for their latest offerings
The company began around the mid 1940’s in Queens, New York along with two other very well known power supply design/manufacturing companies Sorenson and Lambda. Of the three companies, only KEPCO remains in Queens and remains an independent company.
So, that is the background of this component and now let’s get down to describe the component I have carefully extracted from the equipment, and where feasible/worthwhile, tested to ensure full functionality.

MODULEC (USA) – Panel Meter
Made in USA (stamped into the rear of the meter)
Measurement: DC Volts (directly)
Type: Window view
Part #: 135-0533 50v E.S 930032-1602C
Centre Zero
Scale: – 50V to +50V
Mechanical zero adjustment
Substantially all plastic body with a clear acrylic window
Solder tag terminals which can be removed if another form of termination was preferred e.g spade

DIMENSIONS:
Overall body: 75mm height x 57mm x 40mm deep
Movement barrel: 53mm diameter x 30mm deep
Window area (protrudes from the main meter front acrylic face) 71mm wide x 32mm height x 3.75mm window “thickness” (this meter was sitting within a 4mm thick front panel.
Meter cutout in the front panel: 74mm wide x 32.5mm height with a 5.5mm diameter hole which is located 37mm from either side of the window cutout and 15mm lower. This is for the mechanical zero adjustment knob

TESTING:
Although the equipment was fully functional, it is always a good idea to “re-test” once the component has been removed for re-use.
Coil resistance is 49K Ohm
Meter is direct reading, meaning that no dividers etc are required – apply volts and it reads accurately.
Pointer sits exactly in the centre of the scale when no voltage is applied.
I swept voltage across the terminals, both negative and positive, in the range 1V ~ 50V and the meter responded speedily and correctly indicated the voltage present. No sticking pointer and a nice smooth, slightly dampened movement.
NOTE: NO parallax mirror is fitted so you need to read the meter “front on” otherwise optical reading errors will occur.

COSMETIC CONDITION:
USED
Clean face without scratches, cracks or discolouration
NO terminal damage
NO body damage
Nice little analog meter which is ready to serve a useful purpose once again!

I have now placed this meter within sealed pl