Bose AV28, Manual

Page: 35 / 73

35
Adjustment/Performance Verification Procedures
AM Tuner General Test Setup
Measurements are taken from the record
output. Refer to Figure 1.The equivalent field
intensity in dBuV/m is 20 dB less than the
generator output level in dBuV EMF at the
receiving antenna. The signal levels given do
not include this factor.
Figure 1. AM Test Setup
TAP Test Cable Connection
Connect the TAP test cable’s, part number
264565, DB-9 connector to the COM port on
your computer. Connect the test cable’s 3.5mm
plug to the serial data jack on the AV28 media
center. Refer to pages 31 and 32.
1. AM Sensitivity Verification
1.1 Set the RF generator output for a 53
dBuV/m field intensity at the unit’s antenna,
30% AM modulation, 1 kHz and the unit and
RF generator to 1080 kHz.
1.2 Reference a dB meter to the left or right
record output.
1.3 Turn off the RF generator’s modulation.
1.4 The record output should measure
< -20 dB.
2. AM Tuner Adjustment
2.1 Set an RF generator output for a
69 dBuV/m field intensity at the unit’s an-
tenna, 30% AM modulation, 1 kHz and the
unit and RF generator to 1500 kHz.
2.2 Adjust the red slug of T101 until a maxi-
mum output is measured at the record output.
2.3 Set the RF generator and unit to 600 kHz.
2.4 Adjust the black slug of T101 until a
maximum output is measured at the record
output.
2.5 The adjustment of the red and black slug
affects each other. Repeat step 2.1-2.4 until
the measurement at the record output is
optimized for both adjustments.
3. AM Stop Level Adjustment, TAP
3.1 Issue the TAP command TF.
3.2 Set the RF generator to 1080 kHz, 30%
AM modulation, 1 kHz modulation, 56 dBuV/m
field intensity at the unit’s antenna.
3.3 Issue the TAP command T2.
3.4 Set the generator to 1130 kHz (1125 kHz
for Euro and Japan), 61 dBuV/m field inten-
sity.
3.5 Place the unit into seek and verify the unit
stops at 1130 kHz (1125 kHz for Euro and
Japan).
3.6 Switch the RF generator to 49 dBuV/m
field intensity. Place the unit into seek mode
and verify the unit does not stop at 1130 kHz
(1125 kHz for Euro and Japan).
3.7 Issue the TAP command TB. This will
save the adjustment in FLASH.