144 MHz UNI T
Ple ase remove the 50 and 430 MHz units, i f inst al
led, to allow access to test points on the 1 44 MHz
odule.
1.
Local oscillator circuit
( 1) C onnect the DC voltmenter to pin 2 of the
edge connnector for the 1 44 MHz unit.
Confirm th at 11 volts is present, with the
BAND switch set to 1 44-1 46 MHz. Switch
to 1 46-1 4 8 MHz, and check for 11 volts
at pin 3 o f the edge connector.
(2)
Connect the RF probe o f the VTVM to the
L OCAL OUT termin al. Confirm th at the unit
is oscill ating.
(3) Connect a frequency counter to the LOCAL
OUT termi nal. Set the . BAN D switch to
1 44-1 46 MHz, set the RPT switch to SIMP,
and adjust TC 6o6 for a reading of ex actly
11 6.0 MHz. Switch to 146-1 48 MHz and
'
adjust TC 6o7 for a reading o f 11 8.0 MHz.
2.
Receiver section
( 1) Set the HF tr ansceiver to 29 MHz, and peak
the preselector against the marker signal for
maximum sensitivity.
( 2) Connect the DC voltmeter to pin 19 o f the
edge connector, set the BAN D switch to
1 44-1 4 6 MHz, the 1 46-1 48 MHz and
'
confirm that 13 .8 volts is present.
(3) Connect the DC voltmeter to pin 15 o f the
edge connector, and rot ate the FTV-901 R RF
GAIN control fully counterclockwise. The
voltmenter re ading should be 0 volts. In the
fully col ckwise position, it should be 13. 8
volts. A fter confirming these colt ages, please
leave the level at maximum gain.
( 4) Connect the DC voltmeter to pin 1 4 o f the
edge connector, and set the FTV-901R
TUN E control to the center position (1 2
o 'clock). With the BAN D switch in the 1 44-
1 4 6 MHz position, adjust VR1907 for a
reading o f 4 volts. Switch to 1 46-1 48 MHz
'
and adjust VR190s for a reading o f 4 volts.
(5) Conne ct a signal generator to the 1 44 MH z
ANT ja ck, and s et t he FTV-901R BAN D
switdh to 1 44-1 46 MH z. Set fhe signal
generator to 1 45 M Hz, and tune the receiver
to its output. Peak TC1001 -TC1004, T6o4 -
TC 6o6
for a maximum reading on the
H F transceiver S-meter. Re du ce the signal
\gener ator
output, i f
neces- s ary,
to
secure easy viewing
o f the pe ak point.
Switch to the 1 40-1 4 8 M Hz b and set the
'
sign al generator output to 1 4
7
MHz, and
repeak these tr ans formers again while tuned
to the generator frequency. Then reche ck the
results at 1 45 MHz.
3.
Transmitter section.
(1) Connect a dummy lo ad /w attmeter to the
1 44 MHz ANT ja ck. Set VR 601 and VR 602
fully counterclockwise. Set the HF tr ansceiver
DRIV E or CARRI ER control to the center o f
its range (1 2 o 'clo ck). Set the BAN D switch
to 1 44-1 46 MHz.
( 2) Connect the RF probe o f the VTVM to the
collector o f Q6o3 . While transmitting, pe ak
T601-T603 , TC 601, and TC 602 for a
maximum re ading on the VTVM (0.9 volts
RM S nom.).
(3) Connect the RF probe to termin al A on the
1 44 MHz unit. Peak TC 6o4 and TC 6 05 for a
m aximum re ading on the VTVM ( 2.5 volts
RM S nom.).
( 4) Repeat steps ( 2) and (3) on the 1 4 6-1 48 MHz
band. Then recheck the results at 1 44-
1 46 MHz.
(5) Set the FTV-901 R meter switch to the PO
position, and set the transceiver DRIV E or
CARRI ER control for an output o f 1 2 w atts
from the transverter. Set VR 102 for a reading
o f . 8 on the FTV-901R meter.
( 6) Beginning at zero drive, gradually incre ase
the tr ansceiver DRIV E or CARRIER control
until the output from the transverter does
not incre ase more. Do not ex ceed this level.
(7)
Rotate VR 601 slowly cloc kwise, until an
output o f 1 2 watts is secured across the
1 44-1 48 MHz range.
( 8) Rotate VR 602 fully clockwise.
( 9) While t ransmitting, rotate VR 101 to secure
m aximum powe r output on the w attmeter.
( 10) Now rotate VR 602 fully counterclockwise.
While transmitting, slowly rot ate VR 6 02
clockwise, until the power output jus t begins
to fall o ff. Do not go past the th reshold poin t.
(11) Remove the dummy load from the antenn a
jack. While tr ansmitting, confirm th at the PO
indication is . 2 with no load applied. If not,
check the AFP circuit for mal functioning parts.
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