Heathkit IG-18 - Knob Installation

<)::.:)(:
SMALL
OPENING '"
NUT DRIVER
~
KNOB
BUSHING ..
OPENING
LARGE ~
KNOB
Detail 19A
KNOB INSTALLATION
The knobs supplied with this kit use knob bush-
ings that provide permanent positive gripping
without the use of setscrews. Perform the follow-
ing steps carefully since it is very difficult to
remove a knob bushing from a knob once it is
fully inserted. Each knob will be made to align
with
particular switch markings. Whenever you
remove a knob, be sure to replace it on the same
shaft. Refer to Pictorial 19 (fold-out from Page
36) for switch and control locations.
Single Knob Installation
Refer to Detail 19A for the following steps.
( ) Push single knob bushings (#455-50) onto
the multiplier switch shaft, the two fre-
quency switch shafts, and the frequency con-
trol shaft. Then turn all shafts to their full
counterclockwise position.
( ) At one of the switch locations, line up the
pointer of a single knob with the. full counter-
clockwise marking on the panel. Then press
the knob slightly onto the knob bushing.
Page 35
( ) Turn the knob clockwise to each of the
switch stop positions. Check to see that the
pOinter lines up with each panel marking.
NOTE: Perform the next three steps only if the
pointer does not line up at each switch marking.
1. () Turn the knob pOinter to the mid-
pOSition marking on the panel.
2. () Remove the knob from the bushing
and
turn it slightly to line up the pointer
with the midposition marking.
3. ( ) Press the knob slightly onto the knob
bushing.
Then turn the knob to each
switch position and recheck the pointer
alignment. If more than a slight error is
noticed at either end pOSition, repeat
these three steps.
( ) Carefully remove the knob and bushing as-
sembly.
( ) Place the assembly on a table or other hard
surface; then press the bushing firmly and
completely into the knob.
( )
Press the knob and bushing assembly firmly
onto the switch shaft.
( ) Repeat the above Knob Installation steps to
install knobs on the remaining switch shafts.
( ) Turn the Frequency control shaft fully
counterclockwise and set the knob pOinter at
zero.
( ) Repeat the above Knob Installation steps for
the installation of the Frequency control
knob.