Yaesu FT-51R, Техническое дополнение

Страница: 17 / 83

PLL Reference Frequency
D With the wattmeter, dummy load and frequency
counter connected to the antenna jack, and while
tuned to the center of the
UHF
band, key the trans­
mitter and adjust
TC3001
on the 430-Mother Unit,
if necessary, so the counter frequency is within 100
Hz of the displayed frequency on the FT-51R.
Transmitter Power Adjustment
D
Connect the 50-Q d
umm
y load and inline watt­
meter to the antenna jack. Tune to the UHF band
center and select high power output. Key the
transmitter and adjust
VR3001
on the 430-Mother
Unit for 5 W ± 0.2W on the meter.
D Tune to VHF band center and select high power
output. Key the transmitter and adjust
VR2001
on
the 144-Mother Unit for 5 W ± 0.2W on the meter.
144-Mother Unit Interstage Transformer Alignment
D
Connect the
RF
signal generator to the antenna
jack, and connect the 8-Q dummy load and SINAD
meter to the
EAR
jack.
D
Tune the transceiver and the
RF
signal generator to
the band center, and inject a signal modulated with
±3.5 kHz deviation of a 1-kHz tone.
D
Adjust
L2015, L2016
and
L2018
on the 144-Mother
Unit for optimum 12 dB SIN AD (at least -9 dBµ for
12 dB SINAD).
CNTL Unit
FT-51R Technical Suoolement
430-Mother Unit Interstage Transformer Alignment
Important! Before proceeding, ensure the 430-
Mother Unit is grounded to the transceiver rear case
by reinstalling the five previously removed screws.
0
Unplug the CONTACT Unit from the 144-
&
430-
Mother Unit assembly. Next, remove the 5 screws
from the shield case on the 144-Mother Unit, and
remove the shield case.
D Remove the 144-Mother Unit to expose the 430-
Mother Unit. Plug the CONTACT Unit into the
430-Mother Unit. Connect the RF signal generator
to the antenna jack, and 8-Q d
umm
y load and
SIN AD meter to the
EAR
jack.
D Tune the transceiver and the RF signal generator to
the band center and inject a signal modulated with
±3.5 kHz deviation of a 1-kHz tone.
0
Adjust
TC3002-TC3005
for optimum 12 dB SIN AD
(at least -8dBµ for 12 dB SINAD). This complete
the first part of the alignment, re-assemble the
transceiver and proceed to the
Internal System
Alignment Routine.
Internal System Alignment Routine
The remainder of the alignment uses a routine
programmed in the transceiver. This routine simpli­
fies many previously complex discrete component
settings and adjustments with digitally-controlled
settings via front panel buttons and LCD indications.
Transceiver adjustments include:
•
Band & IF Selection
(non-adjustable)
•
S-Meter Full Scale
&
S-1 Adjustment
•
Squelch Threshold & Tight Adjustment
•
Modulation (Low & High) Adjust
D
To begin, set the transceiver to the VHF and UHF
band center, then turn the transceiver off. Next,
press and hold
v�/�'
and together while
powering the radio again. The display now shows
the first setting.
Note that the first two settings are not
adjustable and are left as set from the factory.
In the alignment, each adjustment is selected by
rotating the
DIAL
knob. Alignment is performed by
holding the key for
1h
second
(U
blinks),
then
injecting a signal of the required frequency and level.
Pressing after a level setting or adjustment is
made stores the entry. To exit the alignment routine,
press After performing the system alignment in
it's entirety, individual settings can be returned to and
adjusted should the need arise.
2-9