Heathkit IG-18 User Manual

Page 18
UNITS FREQUENCY SWITCH
Refer to the top view of Pictorial10for the fol-
lowing steps.
( ) Fasten an ll-position rotary switch (#63-
487)
in chassis hole L. Use a control nut
turned down finger tight. Refer to the lugs
on the rear wafer for proper positioning of
this switch.
NOTE: Use 1% resistors in the following steps.
Center each resistor between the switch wafers
UNITS FREQUENCY SWITCH
(63-487)
TOP VIEW
BOTTOM V lEW
before soldering. 3-1/2"
( )' Pass one lead of a 33.3 kQ resistor through
lug R5 (NS). Bend the lead so it lies beside
lugs R6 (NS) and R7 (NS); then connect the
end to lug R8 (NS).
Connect the other lead of this resistor to
lug F5 (S-l),
Connect a 25 kQ resistor from lug F6 (S-l)
to lug R6 (S-3).
Connect a 100 kQ resistor from lug F7 (8-1)
to lug R7 (8-3).
Connect a 50 kQ resistor from lug F8 (8-1)
to lug R8 (N8). Solder both lugs at F8,
Refer to the bottom view of Pictorial 10 for the
following steps.
( ) Pass one lead of a 33.3 kQ resistor through
lug Fll (NS). Bend the lead so it lies be-
side lugs F12 (NS) and F1 (NS); then connect
the end to lug F2 (NS). Now solder lug Fll
(S-2).
Connect the other lead of this resistor to lug
Rll (8-1).
Connect a 25 kQ resistor from lug F12 (S-3)
to lug R12 (8-1).
)
Connect a 100 kQ resistor from lug Fl
(S-3) to lug R1 (S-l),
) Connect a 50 kQ resistor from lug F2
to lug R2 (S-l), Solder both lugs at R2.
BRN
( ) Prepare the following let1LgtllS ()f h'oolrup wire:
2" brown
1-1/2" brown
3-1/2" brown
4" white
4-1/2" white
5" white
Connect a 2" brown
(S-3) and R5 (NS).
( ) Connect one end of a
to lug R5 (S-4). The
connected later.
F2
( )
Connect one end of a brown wire
to lug R8 (S-3), Remove a total of 3/4"
of insulation from the free end of this
wire, which will be connected later.
( ) Connect one end of the 4", the 4-1/2" and
the 5" white wires to both lugs at F4
(S-3). Solder both lugs at F4. The free ends
will be connected later.
This completes the prewiring of the Units Fre-
quency switch. All lugs should be soldered
except the two lugs at RIO, which should have
no connection. Rem ove
the switch from the
chassis and set it aside until it is called for
later,

Heathkit IG-18 Specifications

General

Brand	Heathkit
Model	IG-18
Category	Test Equipment
Language	English