Midian NFBF-10A User manual

1
NFBF-10A
Notch Filter & Band-Pass Filter (1200-2600 Hz)
NFBF-10B
Notch Filter & Band-Pass Filter (700-3000 Hz)
NFBF-10C
Notch Filter & Band-Pass Filter (80-200 Hz)
Manual Revision: 2014-08-20
Covers Hardware Revisions:
NFBF-10: B & Higher

2
SPECIFICATIONS
Operating Voltage 12-18 VDC
Operating Current 3.8 mA
Operating Temperature -30 - +60 C
Input Level 20 mV – 1 V RMS
Input Impedance 600 Ohms
Frequency Range
NFBF-10A 1200-2600 Hz
NFBF-10B 700-3000 Hz
NFBF-10C 80-200 Hz
Band Width 0.5%
Device Gain or Loss Unity
Notch Filter Depth 30 dB
Audio Output Impedance 600 Ohms
Dimensions 3.6” L X 2.25” W X 1.52” H
GENERAL INFORMATION
Notch Filter: As a notch filter, the NFBF-10 will remove the undesirable tone from the incoming audio while
passing the rest of the audio. The NFBF-10A is often used to remove 2175 Hz keying tone from tone remote
systems going into a voice recorder. The NFBF-10C is used to remove CTCSS tones from audio.
Band-Pass Filter: As a band-pass filter, the NFBF-10 will block all audio except for the desired frequency.

3
HARDWARE INSTALLATION
Be certain to follow standard anti-static procedures when handling any of Midian’s products.
Note: This product should be located at the destination point for the audio and not at the source of the audio on a
dry line.
J1: Input Connector: Connect pins J1:2 (red) and J1:3 (green) to the dedicated line coming from the audio
source.
J2: Output Connector: Connect pins J2:2 (red) and J2:3 (green) to the dedicated line going to the destination.
PL1: Power Input: Plug the supplied wall power adaptor into this connector. The wall power adaptor is 18 VDC
output and 110-220 VAC 50/60 Hz input.
HARDWARE ALIGNMENT
Band-Pass: Send the unit a 700 mV p-p signal on the Input line. Monitor P4 with an Oscilloscope or Sinadder. If
using an Oscilloscope tune R-13 (15 turn potentiometer) for maximum amplitude. If using a Sinadder tune R-13
for -12 to -10 dB of sinad. Use an Oscilloscope or Frequency Counter to read the tone frequency on the output.
Notch Filter: Send the unit a 700 mV p-p signal on the Input line. Monitor P5 with a Sinadder. Tune R-14 for -27
to -42 dB of sinad (-30 dB recommended). It may be necessary to tweak R-13 to get R-14 lower.
THEORY OF OPERATION
The NFBF-10 employs a High Q state variable filter. It also uses a 15 turn potentiometer that adjusts the
frequency based on the version ordered. The notch filter function is accomplished by summing the band-pass
audio with the incoming audio, resulting in phase cancellation at the adjusted frequency.

4
TECHNICAL NOTES
MIDIAN CONTACT INFORMATION
MIDIAN ELECTRONICS, INC.
2302 East 22nd Street
Tucson, Arizona 85713 USA
Toll-Free: 1-800-MIDIANS
Main: 520-884-7981
E-mail: [e-mail]
Web: www.midians.com

1
1
2
2
3
3
4
4
5
5
6
6
D D
C C
B B
A A
15K
R4
750K
R7
820K
R3
5.6K
R9
7.5K
R5
100K1%
R6
.001u 1%NPO
C4
100K1%
R10
.001u 1%NPO
C5
56K
R11
62K
R8
10K
R1
10K
R2
P1
P2
TONE IN
P3
TP5
GND GND GND GND
VA
GND
GND
2
1
3
PL1
.47u
C2
.47u
C3
470R
R15
4.7u
C7
10K
11 33
22
R13
*
F1
*
F2
*
D2
*
D3
*
Z3
*
Z4
*
F3
*
F4
*
D4
*
D5
0R
R17
0R
R21
0R
R25
0R
R26
500K
11 33
22
R27
10K
11 33
22
RP2
10K
11 33
22
RP3
10K
11 33
22
RP4
*
11
33
22
10K
RP1
200K
R34
.47u
C21
3.3K
R41
33K
R39
100K
R40
1K
R35
10K
R43
B25
Q1
200K
R38
4.7u
C27
5460 G
S D
Q2
VA
BALANCED OUT
UNBALANCED OUT
BALANCED IN
UNBALANCED IN 560p
C16
560p
C20
560p
C24
.47u
C15
.47u
C18
.47u
C22
LM660
-
+
2
3
1
411
U1:1
LM660
-
+
6
5
7
U1:2
LM660
-
+
9
10
8
U1:3
LM660
-
+
13
12
14
U1:4
VA
.47u
C9
.47u
C19
4.7u
C26
560p
C25
BLACK
J2:2
GREEN
J2:4
YELLOW
J2:5
BLUE
J2:6
RED
J2:3
WHITE
J2:1
YELLOW
J1:5
GREEN
J1:4
WHITE
J1:1
BLACK
J1:2
RED
J1:3
BLUE
J1:6
.47u
C12
620R
R16
.47u
C14
AGC
BYPASSED DC/RING VOLTAGE
UNBALANCED IN
MIXER1 IN
UNBALANCED IN
MIXER2 IN
560p
C17
33K
R12
*
R30
VA
FOR RF BYPAS
LIGHTNING PROTECTION
10K
R28
MIXER/NOTCH/BP/AGC/ADJUSTABLE GAIN OUT
MIXER/NOTCH/BP
AGC/ADJUSTABLE GAIN OUT
AGC PATH
ADJUSTABLE
GAIN PATH
NOTCH/MIXER
NOTCH/MIXER
WITHOUT AGC
WITH AGC
10K
R33
ADJUST
FREQUENCY
OUTPUT GAIN
NOTCH
0R
R22
10K
R31
DEPTH
*
R24
*
R19
*
R36
*
R42
10K
11
33
22
R14
1
2
3 4
5
6
T1:1
1
2
3 4
5
6
T2:1
LM7815
IN
1
GND
2
OUT 3
VR1
VER
A
B
C
R5 R9 R6 R10 R11
5.6K7.5K
1.8K 2.7K
1.2K 33K
100K1%
100K1%
100K1%
100K1%
475K1% 475K1%
56K
56K
51.1K1%
*
Z1
*
Z2
600 OHM
600 OHM
*
C29
*
C30
2.2u
C1
2.2u
C23
JP1:1
JP1:2
JP1:3
JP2:1
JP2:2
JP2:3
JP3:1
JP3:2JP3:3
JP4:1
JP4:2 JP4:3
BP OUT
JP5:1
JP5:2
HP OUT
JP5:3
LP OUT
JP5:4
HP FILTER
BP FILTER
LP FILTER
JP6:1
JP6:2
JP6:3
1u
C31
VAN VAN
VAN
VAN VAN
VAN
EARTH GND
TP1
27K
R32
560p
C8
560p
C10
560p
C11
560p
C13
EP
CJS
2012-08-08 AWS
2014-09-15
D-1
1 of 2 7735
MIDIAN ELECTRONICS, INC.
DATE:
DESIGN:
UPD BY:
REV:
APPR
REV
SHEET PROJECT NUMBER
DOCUMENT NAME
SCHEMATIC
Copyright © 2014
NFBF 10
-
+
3
1
4
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PIC102
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COC7
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PIC802
COC8
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PIC1201 PIC1202
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PIR1101
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COR32
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PIR3302
COR33
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COR34
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PIR3502
COR35
PIR3601
PIR3602
COR36
PIR3801
PIR3802
COR38
PIR3901 PIR3902
COR39
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PIR4002
COR40
PIR4101
PIR4102
COR41
PIR4201
PIR4202
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PIRP101
PIRP102
PIRP103
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PIRP201
PIRP202
PIRP203
CORP2
PIRP301
PIRP302
PIRP303
CORP3
PIRP401
PIRP402
PIRP403
CORP4
PIT101
PIT102
PIT103 PIT104
PIT105
PIT106
COT1:1
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PIT202
PIT203 PIT204
PIT205
PIT206
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COTP5
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PIU102
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PIU107
COU1:2
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PIU109
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COU1:3
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PIU1013
PIU1014
COU1:4
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PIU203
PIU204
PIU205
COU2
PIVR101
PIVR102
PIVR103
COVR1
PIZ101 PIZ102
COZ1
PIZ201PIZ202
COZ2
PIZ301 PIZ302
COZ3
PIZ401 PIZ402
COZ4

PAC402
PAC401
COC4
PAC801
PAC802
COC8
PAC1001
PAC1002
COC10
PAC1101PAC1102
COC11
PAC1301PAC1302
COC13
PAC2902
PAC2901
COC29
PAC3002 PAC3001
COC30
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PAJ107 PAJ108
PAJ101PAJ105
COJ1
PAJ206PAJ204
PAJ203
PAJ202
PAJ207 PAJ208 PAJ201 PAJ205
COJ2
PAJP102PAJP101 PAJP103
COJP1
PAJP202 PAJP201PAJP203
COJP2
PAJP302PAJP301 PAJP303
COJP3
PAJP402
PAJP401
PAJP403
COJP4
PAJP502
PAJP501
PAJP503
PAJP504
COJP5
PAJP602 PAJP601 PAJP603
COJP6
PAMH101
COMH1
PAMH201
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COMH3
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COMH4
PAP101
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COP2
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PAPL103
PAPL101
PAPL102
COPL1
PAR602 PAR601
COR6
PAR702 PAR701
COR7
PAR1002
PAR1001
COR10
PAR1303 PAR1301
PAR1302
COR13
PAR1402PAR1401
PAR1403
COR14
PAR2702PAR2701
PAR2703
COR27
PAR3102PAR3101
COR31
PARP103
PARP101
PARP102
CORP1
PARP202
PARP201
PARP203
CORP2
PARP303
PARP301
PARP302
CORP3
PARP402
PARP401
PARP403
CORP4
PAT101 PAT102 PAT103
PAT104PAT105PAT106
PAT107
PAT108
COT1
PAT201
PAT202
PAT203 PAT204
PAT205
PAT206
PAT207
PAT208
COT2
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PATP101
COTP1
PATP501
COTP5
PAVO202PAVO201
PAVO203
PAVO206 PAVO204
PAVO207 PAVO208
PAVO205
COVO2
COVO4
PAVR103PAVR102PAVR101
COVR1

PAC102
PAC101
COC1
PAC202
PAC201
COC2
PAC302 PAC301
COC3
PAC502 PAC501
COC5
PAC702
PAC701
COC7
PAC902PAC901
COC9
PAC1202PAC1201
COC12
PAC1402 PAC1401
COC14
PAC1502PAC1501
COC15
PAC1602PAC1601
COC16
PAC1702 PAC1701
COC17
PAC1802 PAC1801
COC18
PAC1902
PAC1901
COC19
PAC2002
PAC2001
COC20
PAC2102PAC2101
COC21
PAC2202PAC2201
COC22
PAC2302
PAC2301
COC23
PAC2402PAC2401
COC24
PAC2502
PAC2501
COC25
PAC2602
PAC2601
COC26
PAC2702 PAC2701
COC27
PAC3102PAC3101
COC31
PAD202 PAD201
COD2
PAD302 PAD301
COD3
PAD402 PAD401
COD4
PAD502 PAD501
COD5
PAF102 PAF101
COF1
PAF202 PAF201
COF2
PAF302 PAF301
COF3
PAF402 PAF401
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PAQ10B
PAQ10C
PAQ10E
COQ1
PAQ20D
PAQ20G
PAQ20S
COQ2
PAR102
PAR101
COR1
PAR202
PAR201
COR2
PAR302PAR301 COR3
PAR402PAR401
COR4
PAR502 PAR501
COR5
PAR802PAR801
COR8
PAR902PAR901
COR9
PAR1102
PAR1101
COR11
PAR1202 PAR1201
COR12
PAR1502 PAR1501
COR15
PAR1601PAR1602
COR16
PAR1702
PAR1701
COR17
PAR1902PAR1901
COR19
PAR2102PAR2101
COR21
PAR2202
PAR2201
COR22
PAR2402PAR2401
COR24
PAR2502 PAR2501
COR25
PAR2602 PAR2601
COR26
PAR2802 PAR2801
COR28
PAR3002PAR3001
COR30
PAR3202 PAR3201
COR32
PAR3302PAR3301
COR33
PAR3402
PAR3401
COR34
PAR3502PAR3501
COR35
PAR3602PAR3601
COR36
PAR3802 PAR3801
COR38
PAR3902 PAR3901
COR39
PAR4002PAR4001
COR40
PAR4102PAR4101
COR41
PAR4202
PAR4201
COR42
PAR4302
PAR4301
COR43
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PAU101 PAU102 PAU103 PAU104 PAU105 PAU106 PAU107
PAU108 PAU109 PAU1010PAU1011PAU1012PAU1013PAU1014
COU1
PAU205
PAU202
PAU204
PAU201 PAU203
COU2
PAVO302 PAVO301
PAVO303 PAVO304 PAVO305 PAVO306 PAVO307
PAVO308PAVO309 PAVO3010PAVO3011PAVO3012PAVO3013PAVO3014
PAVO30B
PAVO30C
PAVO30E
PAVO30D
PAVO30G
PAVO30S
COVO3
PAZ101PAZ102
COZ1
PAZ201 PAZ202
COZ2
PAZ301
PAZ302
COZ3
PAZ401PAZ402
COZ4