Heathkit SB-1000 - Secondary Wiring

Page 54
Disconnect the negative ohmmeter lead from
the ground post and connect it to either flat
prong of the line cord plug.
Connect the positive ohmmeter lead to the
other flat prong of the line cord plug. The
ohmmeter should indicate infinity with the
PWR/OFF switch on or off. If you do not obtain
the correct indication, check the wiring of
switches SW3 and SW4, relay K2, and barrier
strip RD. NOTE: Due to the way the safety
interlock is designed, the ohmmeter will read
infinity with the PWR/OFF switch on.
Disconnect the ohmmeter leads from the line
cord plug.
»
SECONDARY WIRING
Refer to Pictorial 7-2 while you make the following
tests.
/
“{) Connect the negative ohmmeter lead to the
ground post on the rear of the chassis. Leave
this lead connected to the ground post until a
step directs you to disconnect it.
Set the ohmmeter to the R x 10k range.
§) Touch the positive ohmmeter lead to plate
choke RFC3 lug 1. The ohmmeter should
indicate 200 kQ or higher. NOTE: It may take
several seconds for the ohmmeter to reach the
indicated reading. This is due to the charging
effect of some of the capacitors in the circuit.
Set the ohmmeter to the Rx 10 range.
cS
Touch the positive ohmmeter lead to solder lug
CN. The ohmmeter should indicate between 80
and 120 ohms.
Touch the positive ohmmeter lead to socket J1
lug 1. The ohmmeter should indicate infinity.
Touch the positive ohmmeter lead to socket J2
lug 1. The ohmmeter should indicate infinity.
Now use your finger to push in on the armature
of relay K1. The ohmmeter should indicate
between 80 and 120 ohms.
Set the ohmmeter to the R x 1 range.
Heathkit
O ‘ouch the positive ohmmeter lead to the top
lead of bridge rectifier D201 on the meter cir-
cuit board. The ohmmeter should indicate 20 Q
or higher.
Disconnect the ohmmeter leads from the Ampli-
fier.
POWER ON
Refer to Pictorial
following steps.
7-3. while you perform the
NOTE: If you wired your Amplifier for operation
from a 120-volt AC source, make sure that the AC
outlet you use has adequate wiring to handle the
large amount of current that is drawn by the Ampli-
fier.
.§) Set the top cover on the chassis as shown. Do
not remove the cover from the chassis until a
step directs you to do so.
CAUTION: Even though the Amplifier has a safety
interlock, there is still a potential danger when the
line cord is unplugged and the cover is removed. This
is due to the charge that remains on the power
supply filter capacitors for several minutes after
power is removed.
Oo Push the PWR/OFF switch to OFF.
Y Push the OPR/STBY switch to STBY.
WY Turn the MULTIMETER switch to HIGH VOLT-
AGE.
WY Plug the line cord plug into a proper AC outlet.
Make sure the outlet matches the voltage you
have the Amplifier wired for (120 VAC or 240
VAC, nominal).
NOTE: If you do not obtain the proper results in the
following steps, immediately push the PWR/OFF
switch to OFF and unplug the line cord. Correct the
problem before you continue.
{) Push the PWR/OFF switch to PWR. The meter
e lights should light and the fan should run (may
be too quict to hear). In addition, the Multi-
meter should indicate approximately 3100
volts.