Heathkit T-2 - Scan 3

ASSEMBLING THE HEATHKIT MODEL T-2 SIGNAL TRACER
The construction of the Heathkit Signal Tracer is not difficult but consideration should be given
the fact that a test instrument will be useful for many years and care taken in construction will
be repaid many times. Test equipment is the best assistant available in service and research
work and it deserves the most careful workmanship possible. Thoroughly study and familiarize
yourself with the instructions, pictorial diagrams and circuit. Do not rush the construction.
Make a good mechanical joint of each connection, then solder it with best quality rosin core radio
type solder. (DO NOT USE FLUXES OR ACID CORE SOLDER.) Hold each joint rigid while
solder cools and then test by attempting to pull joint loose.
Most difficulty in construction results from poor soldering (and use of wrong solder) anc:l reversed
connections (remember that in working on the bottom of the chassis and rear of panel that all
locations are reversed).
Check the parts carefully against the parts list. Identify each part (using the charts on covers
of instruction manual). Be sure to check the packing to avoid throwing away any of the small
parts. Mark the values of condensers and resistors on the schematic diagram beside the part
number.
From time to time, small changes in parts will be made by the Heath Company. All parts sup-
plied will work just as well as the part for which it was substituted. 47, 000 ohms resistors (which
is the new radio manufacturer's rating for 50,000 ohms) may be substituted for 50,000 ohms or
a one watt resistor may be substituted for one-half watt, etc. All substitutions will be of equal
or better quality than the original and will be made in order that a minimum delay will occur in
filling your order.
The newer types of insulated resistors have a higher wattage rating. The t watt size is now rated
at % watt and these are used in this kit. Bolts and nuts are counted mechanically and if a few are
missing please secure locally.
Resistors, condensers and potentiometers have a normal tolerance rating of plus or minus 20%
unless marked otherwise. Therefore, a 1 megohm unit may test between 800,000 and 1,200,000
and be satisfactory. Heathkit circuits are designed to accommodate these variations. Soc-
ket connections are numbered on the bottom of the sockets. Sockets are fastened into the chas-
sis with the wavy metal rings which fit into the groove in the side of the socket. To install, hold
one end of
the ring in the groove and the balance of the ring is then forced over the socket and
into the groove with a screw driver.
Note the direction of the keyways in the sockets from the pictorial diagram.
Begin the construction by mounting the sockets, power transformer, output transformer and bath-
tub condenser, adding solder lugs where indicated. Note: Solder wires to output transformer
lugs #1, #3, and #5 before mounting. Wire the power supply section first followed by the filaments
and ground connections. The resistors and molded condensers are now added. Assemble the
panel by mounting. the several jacks. The jacks are held in place by the special washer with sharp
points which is forced over the body of the jack. Mount the speaker grill and speaker and the
upper selector switch. The panel is held to the chassis by the gain control potentiometer and the
lower rotary selector switch. Complete the wiring by making all connections from the panel to
the chassis. Install the line cord. Assemble the prod as shown on the circuit diagram. Remove
enough of the shielding on the cable to prevent shorting of the crystal. Solder the short ground
BRAID to the shield. The cable with crystal attached is inserted into the prod (having first
removed the cap from the solderless tip of the test prod) and the lead from the crystal pulled
through the hole in the prod tip. This lead is wrapped around the groove in prod tip and the cap
replaced locking it in place. To avoid strain on the crystal lead, it is suggested that several match
sticks be pressed into the prod beside the shielded lead makingthe cable tight in the prod . Install
the phone plug on the other end of the cable as shown.
Upon completion of the wiring, recheck all connections. A suggested way is to follow each con-
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