TM 11-6625-1 668-12
source. The frequency of this external timing source must be 200 times the desired baud rate. The amplitude
of external timing signal must be 6 volts 1 volt into an input impedance of *6000 ohms (*conforms with MIL-
STD-188B). The analyzer will process input signals that are neutral negative or positive on current loops of 20
to 70 milliamperes. It will also accept high level polar signals on current circuits of 20 to 30 ma and low level
polar signals of 6 volts at 1 ma to conform with MIL-STD-188B. Proper sensing is accomplished by means of
the mark polarity switch. The unit operates on 156/230 volts ac single phase 47-63 hz. The self-contained dc
power supply provides 5 volts dc for the analyzer logic levels. The 15 volts do is used to operate the input
d. Oscilloscope OS-206/GGM-15(V). The OS-206/GGM-16 (V), hereafter referred to as the oscilloscope,
is a versatile instrument used in conjunction with its companion unit the signal distortion analyzer. This unit is
designed to display on a 6-inch cathode ray tube, the characters or selected bits of a character being analyzed
by the analyzer. Since the oscilloscope functions in much the same manner as conventional oscilloscopes the
operator should have little difficulty in understanding the operation of the OS-206/GGM-15(V). The function of
the controls on this unit are comparable to the function of corresponding controls on other oscilloscopes.
(1) The FOCUS and ASTIG controls operate in conjunction with each other to obtain-a sharp and
clearly defined trace.
(2) The INTENSITY CRT control is used to adjust the brightness of the oscilloscope display. The
graticule is illuminated and is adjusted by means of the SCALE illumination control located with the INTENSITY
CRT control. The graticule is marked with 10 major vertical divisions, each major division is subdivided into 1-
4 units. The horizontal graticule consists of an upper scale of seven divisions and a lower scale of ten
divisions. The seven division scale is used to measure the width of a bit in a five level code character (Start-
Stop and five bits) while the lower scale is
Figure 1-3. Case, Test Set CY 1-4 672/GGM-15(V).