Tektronix 1L30 Instruction Manual page 44

'J' (no connection)
T (no connection)
' H' Tan-brn-gm ( — 150 V)
' G' Wht-brn-b!k ( + 10V)
'F' W ht-brn-blk-brn ( -f- 1 00 V)
' E' W ht-b lk-red
'O' Wht-grn
' C' W ht-yel
' B' Wht-brn
'A ' W hf
Fig. 4-11. W iring color code to phase lock assembly square pin
connector.
J855. Check the lead dress and all connectors to insure
that no short circuit exists and all connections are correct
(see Fig. 4-11). Power can now be applied and the phase-
lock circuit checked for correct voltages and waveforms. Fig.
4-14 illustrates component layout on the circuit board.
8. If the circuit board is to be replaced, proceed as fol­
lows:
a. Disconnect all the signal and voltage leads 'to' the
assembly. Disconnect the Sealectro connector to the phase
detector at the board.
b. Remove the mounting nuts for the three controls. Push
the FINE RF CENTER FREQ potentiometer and the LOCK
CFtECK switch into the box. Unsolder the lead to the BNC
connector. Remove the circuit board mounting screws and.
the mounting screws to the square pin connector.
c. Slip the circuit board out of the box.
place.
Remounting the Phase Lock Assembly
1. Replace and remount the assembly using the reverse
of the procedure to remove the assembly. Be certain to use
the correct mounting nut for the INT 1 MHz REF FREQ switch.
2. Refer to the Phase Lock diagram and Fig. 4-11 for the
correct voltage and signal cable hook up. Make certain the
dot on the FINE RF CENTER FREQ control is indexed
center of the control range when the knob is replaced.
Soldering Techniques
Ceramic -Strips. A soldering iron with a wedge-shaped
tip should be used because it concentrates the heat on the
solder in the terminals.
as possible to produce a full flow joint.
bearing solder is used to establish a better bond to the
plated notches in the ceramic strip. Occassional use of
ordinary 60/40 solder will n'ot break the bond, but it is ad­
visable to use solder containing about 3% silver for the main­
tenance of Tektronix instruments. This solder may be pur­
chased directly from Tektronix, Inc; order by Part Number
251-0514-00.
The following techniques are suggested to i*emove and
replace components on the ceramic strips.
1. Grip the lead with needle-nose pliers. Apply the tip
of the soldering iron to the connection at the notch, then
pull gently to remove the lead.
2. Clean the leads on the new component and bend them
to the correct shape to fit the replacement area. Insert the
leads, making certain the component seats the same as the
original.
3. Apply the iron to the connection; then apply only the
amount of solder required to form a good electrical con­
nection.
4. Do not attempt to fill the notch with solder; apply only
enough solder to cover the wires adequately and form a
small fillet.
terminal strips. Clip off the excess lead that extends beyond
the soldered joint.
Some components can be damaged by heat.
heat sink, such as a pair of needle nose pliers, he-
mostat or forceps, between the component and the
connection will protect the component from exces­
.
sive heat.
Ceramic Strip Replacement.
then use a 3 /s inch diameter by 3 inch long plastic or hard­
wood dowel and a small (2 to 4 oz.) mallet to knock the
stud pins (Fig. 4-12) out of the chassis.
the dowel on the end of the stud pin protruding through the
chassis. Rap the dowel smartly with the mallet. When both
studs of the strip have been loosened in this fashion, the
strip is removed as a unit. The spacers will probably come
out with the studs. If not, they can be pulled out separately.
Repair or re­
An alternative method to remove the terminal strip is to
use diagonal cutters to clip off the studs. The ceramic strip
is removed and the studs pulled from the chassis with a pair
of pliers.
After the damaged strip has been removed, place the un­
damaged spacers in the chassis holes. Then, carefully press
the studs into the spacers until completely seated. If neces­
sary, use a soft mallet and tap lightly, directly over the
stud area of the strip.
at
the
Component Replacement
The physical size and shape of the replaced component
may affect the performance of the circuit; therefore, it is
best to duplicate the original component as closely as pos­
sible. Parts orientation and lead dress should also dupli­
cate those of the original part. Many of the components are
Maintenance— Type 1L30
It is important to use as little heat
Over-filling the notches may result in cracked
NOTE
Unsolder all connections
A special silver­
frv. ■ . -
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Place one end of
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