11
Data Separator Adjustment Procedure - DC-4 Disk Controller
Adjustment of the data separator on the DC-4 disk controller board requires
some special equipment, such as a good oscilloscope. This adjustment requires some
technical ability and should only be done by qualified personnel. This adjustment
has been performed at the factory on assembled units.
1.)
Connect the oscilloscope to test point 1 (TP 1) on the DC-4 board. The ground
lead of the scope should be connected to the ground screw on the regulator or
other ground on the DC-4 board, not on the ground pin of the connector bus.
2.)
Adjust potentiometer R15 to obtain a 1.4 volt DC reading. This reading can be
verified using a good high impedance DC voltmeter.
3.)
Connect the oscilloscope to test point 2 (TP 2) on the DC-4 board. Adjust
potentiometer R16 for a 2.0 MHz square wave. This measurement can be verified
with a good frequency counter.
4.)
After correct operation of the board is verified, secure each of the
potentiometers by using liquid 'silicon rubber cement or equivalent. Do not
pour an epoxy or cyanoacrylate type glues down inside the potentiometer as
these could ruin the part.