Ampex 351 - Page 79

Reproduce Alignment:
Step I:
Remove the head cover.
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
Step 7:
8-6
Long Screwdriver (approximately 7 inch bit).
Small Screwdriver.
ALIGNMENT AND PERFORMANCE
CHECKS
15
15
NOTE
In catalog numbers 30950 and 30960
slave electronics, relay 4K3A contacts
serve as interconnection between the
master and slave oscillators. Catalog
number 30750 slave electronics did
not have relay 4K3.
Place the METER AND OUTPUT
switch in the PLAYBACK position.
Terminate the output in a nominal
600 ohms (LINE TERM switch in
the ON position or use a 600 ohm
external load).
Set the EQUALIZATION switch to
the desired speed.
89-0144
Issue A
Number
Ampex Catalog
31331-01
31321-01
31311-01
31312-01
Start the standard tape. The first tone
on all standard tapes is a reference
level, 700 cycles for 714 and 15 inches
per second, and 500 cycles for 3%
inches per second. For 15 inches per
second, adjust the playback level
control so the VU meter reads zero
or a VTVM across the output reads
+ 8 dbm. For 3% or 714 inches per
second adjust the playback level con 
trol to a convenient meter reading for
checking alignment and response.
The next tone will be 15,000 cycles
at 714 and 15 inches per second, and
7500 cycles at 3% inches per second
for adjusting reproduce head align 
ment. Take the number 8 nut driver
CAUTION
The standard alignment tape used in
the following procedures may be
partially erased if the record and
reproduce heads are permanently
magnetized. Demagnetize the heads
before proceeding. Do not replace the
head cover on the head assembly.
3% inches per second (ips)
714 inches per second (ips)
inches per second (NAB)
inches per second (AME)
A-c Vacuum Tube Voltmeter capable of indi 
cating rms voltages of .004 or less.
Audio Oscillator with stable output from 50
cps to 15 kc.
Earphones or Speaker for Aural Monitoring.
Nutdriver, number 8 ('A inch).
Reel of unrecorded tape.
Equipment Required:
Ampex Standard Alignment Tapes for *A
Inch Tape.
Speed
With the equipment connected as
shown and all power switches in the
ON position, thread an Ampex stan 
dard tape for the appropriate speed
along the prescribed path.
the relay energized. When the STOP button
on the tape transport is pressed, the 115 volt
d-c no longer reaches pin 3 of 5J7 and relay
3K1 is de-energized and drops out. Slave elec 
tronics relay 4K3 provides a coupling contact,
4K3A, when both electronics arc in the record
mode (concurrent recording). This relay re 
mains energized for a short time after the
second relay 3K1 is de-energized to maintain
oscillator coupling during the decay period
of the oscillators.
CAUTION
Before performing alignment and
performance checks on stereophonic
equipment see special notes on align 
ing stereophonic equipment.