CHANGING LIMITER RELEASE TIME TO ONE
SECOND
Remove resistor R741 (about 15 mm behind ribbon cable as-
sembly W813).
CHANGING LIMITER THRESHOLD PRESETS
1.Select the equivalent resistor values for the desired limiter
thresholds from the following table. Then fill in the following work-
sheet with the resistor selections.
Limiter Threshold
R
equiv
(dBm into 600 Ω)
(kΩ)
0
18
1
21
2
25
3
30
4
35
5
41
6
47
7
54
8
62
9
71
DIP Switch S701
Limiter Threshold
Position
Position
—
2
3
up
up
high
down
up
med. high
up
down
med. low
down
down
low
2.Remove resistors R721, R731, R732, R733, R734 and R735
(surrounding IC U704).
3.Locate empty pads X732, X733, X734 and X735 (surrounding IC
U704).
1
4.Select a
/
W, 1% resistor closest in value to R1 (from the work-
4
sheet), and solder it to the holes of X732.
Note: Use parallel or series combinations of resistors to match
the chosen values as closely as possible if 1% resistors are not
available.
5.Calculate resistor R5 value as follows:
R5 =
R2
1
Select a
/
W, 1% resistor closest in value to R5 and solder it to
4
the holes of X733.
10
Limiter Threshold
(dBm into 600 Ω)
10
11
12
13
14
15
16
17
18
R
(above)
equiv
dBm
—
_____
_____kΩ = R1
_____
_____kΩ = R2
_____
_____kΩ = R3
_____
_____kΩ = R4
1
1
1
–
R1
6.Calculate resistor R6 value as follows:
1
Select a
/
the holes of X734.
7.Calculate resistor R7 value as follows:
R7 =
R
equiv
1
(kΩ)
Select a
/
the holes of X735. (See Changing Limiter Threshold Presets:
81
Samples Calculations later in the Appendix for an example of
93
limiter threshold preset component calculations.)
105
CHANGING LIMITER THRESHOLD PRESETS:
122
SAMPLES CALCULATIONS
139
For the following limiter thresholds:
156
DIP Switch S701
175
Position 2
194
215
up
down
up
down
1.Obtain a 105 kΩ, 1/4 Ω, 1% resistor and solder it to the holes of
X732.
2.Obtain a 150 kΩ, 1/4 W, 1% resistor and solder it to the holes of
X733.
R
5
=
3.Obtain a 52.3 kΩ, 1/4 W, 1% resistor and solder it to the holes of
X734.
R
6
35,000
=
4.Obtain a 49.9 kΩ, 1/4 W, 1% resistor and solder it to the holes of
X735.
R
7 =
18,000
1
R6 =
1
1
–
R3
R1
W, 1% resistor closest in value to R6 and solder it to
4
1
1
1
1
–
–
R4
R1
R5
W, 1% resistor closest in value to R7 and solder it to
4
Limiter Threshold
Position 3
—
up
high
up
med. high
down
med. low
down
low
1
= 151.4 kΩ
1
1
105,000
62,000
1
= 52.5 kΩ
1
1
105,000
1
1
1
1
105,000
150,000
= 49.4 kΩ
1
–
R6
R
equiv
dBm
—
12
105 kΩ=R1
8
62 kΩ=R2
4
35 kΩ=R3
0
18 kΩ=R4
1
52,300