Analog-To-Digital Converter Adjustments - HP 8566B Adjustment Manual

3-206 Adjustments
The Analog-to-Digital Ramp Converter is adjusted at zero and
full-scale by injecting a 0 V dc input and + 10 V dc input and adjusting
the OFFS and GAIN controls until the ramp output at A3A8TPll
toggles high to low. This sets the horizontal
trace display; when the sweep ramp input is at 0 V dc (the left
graticule edge), trace position 1 is set, and when the sweep ramp
input is at + 10 V dc (the right graticule edge), trace position 1000 is
set.
This procedure requires a + 10 V dc source which is stable and
noise-free. A simple supply circuit which can be built with common
components is illustrated in Figure 3-108. If these components are
unavailable, the alternate procedure provided below (using only the
digital voltmeter) can then be used.
D C S U P P L Y
D I G I T A L VOLTWTER
Figure 3-100. Analog-To-Digital Converter Adjustments Setup
Oscilloscope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HP 545OlA
Digital Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HP 3456A
Low-Noise DC Supply (Optional) . . . . . . . . . . . . . . . . . . . . See Figure 3-108
1. Position spectrum analyzer upright as shown in Figure 3-100 and
remove IF-Display Section top cover.
2. Set spectrum analyzer LINE switch to ON and press C-1.
3. Procedure using Low-Noise DC Supply is illustrated in Figure 3-108.
a. Key in (-1 TRACE A and SWEEP (-1.
b. Disconnect cable 0 (black) from sweep ramp input A3A8Jl.
c. Short A3A8TP4 to A3A8TP5 or connect SMB snap-on short to
end points for the CRT