Hammond L series User Manual

SECTION
IV
PRACTICAL
SERVICE
SUGGESTIOIMS
4-1.
GENERAL.
-
This section contains
perform-
ance
standards, adjustment
procedures, and
troubleshooting information.
NOTE
Before
making any
checks
or
ad-
justments involving ampHfiers,
test
all
tubes to be sure they
are oper-
ating properly.
4-2.
ORGAN
PERFORMANCE CHECK.
-
To
prepare
the
organ for
performance
check
proceed
according to
the following.
a.
Place
all
tabs in
up
(ofQ
position.
b. Push
drawbars
in to Umit of
motion.
c. Set swell
pedal for
maximum output.
d. Connect
meter
to speaker terminals.
NOTES
At certain
steps in
the following
procedure,
conditions
other than
above may
be specified.
Return
controls
to
above
conditions
as
each step is
completed.
Drawbars,
pedals
and keys are
called
out
by
number,
beginning
with
No.
1,
at left end of
row.
4-3.
EtiUIPMENT
REQUIRED.
-
a. VTVM,
Commander
870
or equivalent.
b. Oscilloscope, Tektronix
503
or
equivalent.
4-4.
PROCEDURE.
-
a.
Depress UPPER
DRAWBARS
tab and
pull
drawbar
No.
1
to
position
8.
Play
lowest
C,
on upper^
manual (Frequency
25)
and
observe
meter. If
output is
not
between 1.6V
and
2V
rms,
adjust
GAIN
ADJUST
on
power
ampUfier
to bring
output
into
range.
b.
Maintain
conditions of step
a.
Depress
VOLUME SOFT
tab. Output
should
drop
to
range of
0.69 to
0.9 volts
rms.
c.
Set pedal drawbar at position
8.
Depress
lowest
C
pedal.
Output
should be between
4V and
5.5V rms.
NOTE
If
output
is
not
within
specified
range, select Rl,
Figures
5
—
1
through
5-4,
from
1.8i2
to 21
Q.
to
bring
output
into range.
d. Maintain
conditions
of step
c. Depress
VOLUME
SOFT
tab.
Output should
drop
to 0.8V
to
1.5 V
rms.
e.
Return
VOLUME
SOFT
tab to "up"
position.
Maintain
other
conditions of
step
c. Play
all
pedals
to be sure
output
changes
smoothly
from note
to note.
f.
Make
upper
manual preset
listening
check.
Hold
down F,
A,
C chord near
center
of
upper
manual.
1.
Trumpet.
Set
up upper
drawbars to
00
6688 888. Press
TRUMPET
preset
and
then
UPPER
DRAWBARS preset.
The
musical
quality
should
be identical.
2.
Clarinet.
Set
up upper
drawbars
to
00
8080 800. Press
CLARINET
preset
and
then UPPER
DRAWBARS preset.
The musical
quaUty
should
be
identical.
3.
Full
organ.
Set
up upper
drawbars
to
86
8868
446.
Press
FULL
ORGAN
preset
and
the
UPPER
DRAWBARS
preset.
The
musical
quality
should
be
identical.
g.
Make
lower
manual
preset listening
check.
Hold
down F,
A,
C chord near
center
of
lower
manual.
1. Set up
lower
drawbars
to
6644 222.
2.
Press
ENSEMBLE
preset
and then
LOWER
DRAWBARS
preset.
The
musical quality
should
be identical.
h.
Percussion
cutoff
control
and
output
checks.
1.
Cut-off.
With
only THIRD
HARMON-
IC, FAST
DECAY,
and
UPPER
DRAWBARS
tablets
depressed
and
all
drawbars
pushed in,
hold
down
lowest
C
key
on
upper
manual
and
adjust
percussion
cut-off
control
on
preamplifier
chassis
to point
at
which
output signal
is just barely
audible.
2. Output
voltages.
With only
UPPER
DRAWBARS
and
SECOND
HAR-
MONIC
tablets
depressed,
press
lowest
C
key
on
upper
manual.
Output
volt-
ages
across
speakers
should
be
between

Hammond L series Specifications

General

Brand	Hammond
Model	L series
Category	Musical Instrument
Language	English