CRYSTAL CALC ULATI ONS FOR CRYSTAL CONT
ROLLED TRANSCEI VER OPERATION W ITH THE
EXTERNAL VFO OR THE TRANSCEIVER INTERNAL
FI X OSCIL LATOR,
PB1534
The crystal holders accept standard HC- 2 5 /U type crys
tals. All crystal frequencies must fall between 8.700
KHz
and 9.200
KHz.
A trimmer capacitor has been
connected in parallel w ith each crystal to perm it proper
frequency adjustment. Adjustment of this trimmer will
change the crystal frequency approx imately 1
KHz.
The correct crystal frequency for any desired operating
frequency. may be determined by the following formula :
F x = ( F1 + F c ) - Fo
F x = ( F 1+ F e ) - Fo .
where
F x
is the crystal frequency.
Fo
is the desired operating frequency. and the constant
( F 1 + F c )
is taken from the table.
F req uency T a ble
( F 1 + Fe)
Unit :
KHz
BAND
LSB
U
SB
AM/CW
160
10701.5
10698.5
10699.3
80
1 2 70 1 .5
1 2698.5
12699.3
40
16201.5
16198.5
16199.3
20
2 3 201.5
2 3 198.5
2 3 1 99.3
15
3 0 201.5
3 0198.5
30199.3
lOA
3 7 201.5
3 7198.5
3 7199.3
108
3 7 701.5
3 7698.5
3 7699.3
lOC
3 8 201.5
3 8198.5
3 8199.3
100
3 8 701.5
3 8698.5
3 8699.3
For Example :
Find the proper crystal for operation at 3 900
K Hz
LSB on the 80 meter band .
From the table find the constant ( Fl
+
Fe) for
LSB
operation on this band. The constant is 1 2 70 1 . 5 . thew
fore Fx
=
1 2 701.5 - 3 900
=
8801.5
KHz.
CW FILTER INSTALLATION
1 . Remove top cover of tran sceiver cabinet and locate
printed circuit boards
.P8-13 1 5A and PB- 1 1 83 8 .
2 . Remove two screw s holding
PB- 1 3 1 5 A
to the U
shaped bracket. Remove two screws hold ing the U
shaped bracket to the shield plate. located between
the two boards.
3 . Remove P B- 1 3 1 5 A f r o m the chas s i s conne c to r
r e c e p t i c a l . G e n t l y , r o c k the c i r c u i t b o a rd out o f
the connector.
4. Remove the two screws holding the sh ield plate and
l i ft out of the cabinet.
5 . Grasping the U-shaped brackets stil l attached to
P B- 1 1 83 8
gently. rock the circuit board out of the
connector.
6. With
PB-1 1 8 3 8
removed from the chassis. remove
C-10 and C- 9
(
.01 u F) capacitors from board. Install
XF-3 0C CW filter in position ind icated using the
nuts and lockwashers prov ided. Solder the four filter
term inals to the board.
7 . Re-install
P8-1 1 838
into socket. screw shield plate
to chassis. and re- install
P 8 - 1 3 1 5 A
into socket. Re
place all attaching screws.
This completes the CW filter installation. The filter
provides a 600
Hz
bandpass w hen the m ode switch
is placed in the CW position. Tran sicever alignment
is not required for this installation.
X F3 2 A
SSB FILTER
CW Filter Solder Connections
-
2 0
-
