Radio Shack TRS-80 PT-210 Service Manual page 57

a FSK Frequency Adjustment
10 CN1 1
VR2
0 -
0
VR3
VR 1
C N 3 g CN2 g
f f g
- I
mo
z
Figure 54.
Figure 55.
Note:
Do not touch Variable Resistors (VR1, VR2, and VR3)
except for maintenance purposes. (Precise adjustment
was made at the factory before shipment.)
*
A Frequency Counter capable of measuring frequencies
from 1 to 3 k Hz is required for adjustments.
Receiving Frequency Adjustment (VR1)
(See Figure 55.)
Power ON
I
i
Set Speed S W
to 300 Baud
i
Set Mode S W
to ON LINE
+
Ready to Adjustment
Connect to
4 - 7
telephone line
Y
Receive Test Data
from Remote Computer
I
I
Note:
Repetition of the
Alphabet
(A.B.C.D
.....
X.Y.Z.A.B.C.D
...I
Ã
Print Received is recommended for
Data
test
data
I
t
Turn
VR1
so the
I
1
Test Data printing correctly.
1
1
Adjust for correct printing
1
Adjustable range
I
I
Figure 56.