anything. If there is no change, that would tend to eliminate the drive signal as a source
of problems.
Some devices are simply very sensitive to ANY stray capacitance between the input
and output sides. Some devices are extremely sensitive to interference coupled to pin
7, which (unwisely) provides a connection to the photo-transistor base. To test this as a
possible problem source, try snipping off pin 7 on your device and see if that affects the
results beneficially. If it does, you might want to consider designing your own ultra-low-
stray-capacitance socket and daughterboard, or avoiding sockets entirely and using
soldered devices instead.
54
Summary of Contents for AVRQ-4-B
Page 41: ...41...
Page 51: ...Bottom side 51...
Page 67: ...PCB 158R5 LOW VOLTAGE POWER SUPPLY...
Page 68: ...PCB 104G KEYPAD DISPLAY BOARD...
Page 69: ...PCB 228C OP AMPS AHV AND XHV UNITS...
Page 71: ...DUT WIRING ON STANDARD DAUGHTERBOARD PCB 267D...
Page 72: ...DUT WIRING ON SO 8 DAUGHTERBOARD PCB 314A...
Page 73: ...DUT WIRING ON WDIP16 DAUGHTERBOARD PCB 325A...
Page 75: ...PERFORMANCE CHECK SHEET 75...