QuadTech 1657 RLC Digibridge Instruction Manual page 35

Screw K must contact etched-circuit ground. A washer is supplied
(under screw head) if necessary to do so.
5.6.2 Access. Figures 5-7 and 5-8.
Interior locations that are important for trouble analysis
are shown. Notice the clues to pin numbering; square pads on etched
board are generally pin 1. Conversion items are shown, to make a 1657-
9700 function as a 1657-9800, or vice versa. (See para 3.1 for line-
frequency consideration.) Conversion involves relocating 2 jumpers and
substitution of precision oscillator U7; refer to parts list, Section 6.
(Thus, with a spare oscillator, one can obtain test frequencies of 100,
120, 1000 Hz.) Notice: if your instrument has separate crystal Yl, it is
changed instead of U7; inquire.
The 2 arrows with letters "A" show approximate area (front right
corner) of analog circuitry. The rest is digital.
SERVICE 5-9