Eberline RO-2 - Page 17

"E -
MODEL RO-2
3. Since the amplifier can be completely destroyed by
as insignificant an act as touching it improperly, every
possible precaution should be taken to make sure that
all static charges are eliminated around the unit. Do not
remove the shorting device shipped with the new ampli-
fier until other shorting clips are in place. Leave the
clips in place until the amplifier is soldered in. Then
transfer the clip to the terminal or other place where the
lead was soldered until installation is complete. Make
sure that the soldering iron is grounded not only to in-
strument chassis ground but also to the shorting clip
around the amplifier when soldering first starts.
4. High Impedance Components
“Several components connect to the point in the circuit
where the extremely minute ion chamber current flows.
It is of utmost importance that they be clean, free of
fingerprints, and carefully installed. They include pin 2
of Al, the two feedback resistors КІ and R2, and the
two reed switches S2 and S3. The leads of these com-
ponents are not supported on insulators. They are air
insulated at all points. All wiring in the chamber
assembly should be dressed away from the high
impedance components.
If leakage currents appear to be a problem, make sure
the silica gel in the desiccant box is dark blue.
Temperature cycling, as described in the note in part A
of this section, may correct the problem. The use of a
high purity, mild, Freon® solvent spray to clean the
high impedance components may help. Do not use alco-
hol spray since it will dissolve the aquadag coating used
in the assembly.
REFERENCE LOCATION ON SWITCH
DESIGNATION VALUE 4 (TOP VIEW, METER FORWARD)
C4 33 pF Front (upper)
С5 15 pF Front (lower)
R4 ^ | IMQ Right rear
RS 110k Right rear
R6 430k Left front
R7 430k Right side
R8 68k Left side
Table 4-1. Range Switch Component Locations
11
СНАМОЕВ