Shure M367 User Manual page 10

CHANGING LIMITER RELEASE TIME TO ONE SECOND
Remove resistor R741 (about 15 mm behind ribbon cable
assembly 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
Position 2 Position 3
up up
down up
up down
down down
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).
4. Select a 1/4 W, 1% resistor closest in value to R1 (from the
work 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 =
Select a 1/4 W, 1% resistor closest in value to R5 and solder it
to the holes of X733.
Limiter Threshold (
dBm into 600 Ω)
10
11
12
13
14
15
16
17
18
R
Limiter Threshold
equiv
– dBm
high _____ kΩ = R1
med. high _____ kΩ = R2
med. low _____ kΩ = R3
low _____ kΩ = R4
1
1 1
–
R2 R1
6. Calculate resistor R6 value as follows:
Select a 1/4 W, 1% resistor closest in value to R6 and solder it
to the holes of X734.
7. Calculate resistor R7 value as follows:
R
equiv
(kΩ)
R7 =
81
Select a 1/4 W, 1% resistor closest in value to R7 and solder it
93
to the holes of X735. (See Changing Limiter Threshold Presets:
105
Samples Calculations later in the Appendix for an example of
122
limiter threshold preset component calculations.)
139
CHANGING LIMITER THRESHOLD PRESETS: SAMPLES
156
CALCULATIONS
175
For the following limiter thresholds:
194
DIP Switch S701
215
Position
2
up
(above)
–
down
up
down
1. Obtain a 105 kΩ, 1/4 W, 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
3. Obtain a 52.3 kΩ, 1/4 W, 1% resistor and solder it to the holes
of X734.
R
4. Obtain a 49.9 kΩ, 1/4 W, 1% resistor and solder it to the holes
of X735.
R
7 =
10
1
R6 =
1
–
R3
1
1 1
– –
R4 R1
Limiter Threshold
Position –
3
up high
up med. high
down med. low
down low
1
1
1
5 =
105,000
62,000
1
1
1
6 =
35,000 105,000
1
1 1
18,000
105,000 150,000
= 49.4 k
1
R1
1 1
–
R5 R6
R
equiv
dBm –
12 105
kΩ=R1
8
62 kΩ=R2
4
35 kΩ=R3
0
18 kΩ=R4
= 151.4 k
= 52.5 k
1 1
52,300