Bird Technologies 3128A - Manual (Page 31)

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If there is any evidence of contamination inside the RF line section, the accessible portions should be cleaned and
the interior carefully blown out. Keep all connections tight, and keep the nut of the meter cord plug turned tight on
the line section DC jack. This connection may often be serviced by simply loosening the nut of the DC plug, rotating
the body several times through a fraction of a turn and retightening the knurled nut securely.
Meter Replacement
Disassembly
1. Remove four screws securing the front panel.
2. Pull front panel forward until it clears the lamps and switches.
3. Lay the front panel face down so that the meter terminals are accessible.
4. Remove leads taking note of wire locations, red to positive, black to negative.
5. Remove nuts securing the meter bezel.
6. Remove meter.
7. Reassemble by reversing steps 6 to 1.
Note: When installing the four meter mounting screws, torque the to 10 in/lbs.
Contact Adjustment
In cleaning the socket bore the operator should be careful not to disturb the spring finger of the DC contact. It is
important that the operating position of this part be properly maintained. If the spring finger of the DC contact
requires adjustment, it may be done manually if carried out with care. The tip must be positioned far enough out to
maintain good contact with the element but not so far as to interfere with easy entry of the element body. The DC
jack, with attached spring finger, may be detached for service by removing the two 4-40 fillister head machine
screws which fasten it to the side of the RF line section. Then lift off the jack assembly carefully to avoid losing the
small Teflon insulating bead that straddles the base of the phosphor bronze spring and nests in a counterbore on the
side of the RF body. When replacing the assembly, be sure that the bead is again properly inserted.
Fuse Replacement
Use a screwdriver to remove fuse receptacle, insert new fuse and replace.
CAUTION
Do not attempt to check the microammeters with an ohmmeter. Damage to the
movement or pointer will result.
CAUTION
Replace with only the same type and rating fuse. T, 125 mA, 250VAC.