![background image](http://html.mh-extra.com/html/icom/ic-910h/ic-910h_instruction-manual_611497076.webp)
D
Adjust the CR-293
The CR-293 has 0.5 ppm accuracy as the default,
therefore normally you do not need any adjustment
after installing the optional high stability crystal unit.
q
Remove the top cover and PA unit cover as shown
in the diagram on p. 71, if required.
w
Remove P551 from J40 on the PA unit.
e
Connect a frequency counter to check point P551
as shown at left.
r
Turn the trimmer capacitor of CR-293 to adjust to
60.400000 MHz.
t
Return the top cover and PA unit cover to their orig-
inal positions.
NOTE: CR-293 is a very delicate device, use the ap-
propriate tools only for adjustment.
74
11
OPTION INSTALLATIONS
By installing the CR-293, the total frequency stability
of the transceiver will be improved.
q
Remove the bottom cover as shown in the diagram
on p. 71.
• Remove the UX-910 if you have installed it. (p. 73)
w
Remove the 6 screws from the PLL shield cover,
then lift up the PLL shield cover.
PLL shield
cover
e
Disconnect the FFC (Flexible Flat Cable) from the
DISPLAY unit and the connection cable connectors
from J501 and J1051 on the MAIN unit.
r
Remove the 5 screws from the PLL unit, then lift up
the PLL unit.
t
Unsolder the original reference crystal, then remove
it.
•
The original reference crystal unit is soldered at both the
top and bottom sides of the PCB (Printed Circuit Board).
J501
Original crystal
CR-293
J1051
Flexible flat cable
Unsolder the
original
crystal.
y
Install the CR-293 and solder the leads.
u
Return the PLL unit, PLL shield cover and bottom
cover to their original positions.
CR-293
soldering
points
Original crystal soldering point
n
CR-293
HIGH STABILITY CRYSTAL UNIT
J40
P551
2Lo Freq.
check point
(60.400000 MHz)
PA unit
Содержание IC-910H
Страница 1: ...INSTRUCTION MANUAL VHF UHF ALL MODE TRANSCEIVER i910H ...
Страница 86: ...84 MEMO ...
Страница 87: ...85 MEMO ...