Midian VPU-12A User manual

1
VPU-12A
16-Code Voice Inversion Scrambler
Manual Revision: 2013-04-01
Covers Software Revisions:
VPU-12A: 3.0 and higher

2
SPECIFICATIONS
Operating Voltage +3.7-15 VDC
Operating Current 3.5 mA
Operating Temperature -30 - +60 C
Frequency Response – 2100 Hz 300-1700 Hz
Frequency Response – 3100 Hz 300-2500 Hz
Frequency Response – 4100 Hz 300-3600 Hz
Audio Output Impedance <10K
Input Level 150-1000 mV p-p
Input Impedance >60K
Frequency Error <0.25%
Device Gain or Loss Unity
Inversion Frequency Range 2100 – 4100 Hz
Number of Inversion Codes 16
GENERAL INFORMATION
Midian’s VPU-12A voice inversion scrambler provides an entry level of voice security for two-way radio
communications. The VPU-12A provides up to 16 different inversion frequencies that are selectable using 4-line
binary. These inversion frequencies are programmable using Midian’s KL-3. The VPU-12A is compatible with
Midian’s VPU-12, but adds the benefit of mode indications.

3
PRODUCT PROGRAMMING
The VPU-12A comes preprogrammed with default inversion frequencies (see Table 1 below). By configuring the
4-line binary outputs, the desired inversion frequency can be selected. Other default features are a Power-Up
State of Clear, a Mode Select of Momentary and a Mode Polarity of Active Low. If different parameters are
needed, the KL-4 programming interface and MPS programming software will be needed.
Table 1 Grounded Wires –
Frequency Select
(A, B, C, D)
Binary Code # Inversion
Frequency
(Hz)
Org/Wht, Gray, Gray/Wht, Grn/Wht 0000 1 2100
Org/Wht, Gray, Gray/Wht 0001 2 2341
Org/Wht, Gray, Grn/Wht 0010 3 2423
Org/Wht & Gray 0011 4 2587
Org/Wht, Gray/Wht, Grn/Wht 0100 5 2632
Org/Wht, Gray/Wht 0101 6 2728
Org/Wht, Grn/Wht 0110 7 2868
Org/Wht 0111 8 2976
Gray, Gray/Wht, Grn/Wht 1000 9 3023
Gray, Gray/Wht 1001 10 3107
Gray, Grn/Wht 1010 11 3333
Gray 1011 12 3388
Gray/Wht, Grn/Wht 1100 13 3500
Gray/Wht 1101 14 3729
Grn/Wht 1110 15 4096
None 1111 16 3276
The VPU-12A is programmed using the KL-4 programming interface and MPS programming software. Please
reference the KL-4 manual for setup of the programming hardware and software.
Set the parameters of the software to fit the application. If any clarifications on a feature are required, move the
mouse cursor over the feature name until the question mark appears and right click, a definition of the feature will
be shown.
After entering the parameters, save the file by going to File - Save As. Enter the file name in the File Name block
and click Save. Saving the file will allow for quick and easy reprogramming of units.
KL-4 Programming: Plug the board onto the KL-4 connector labeled as “P4”. Push and hold the power button
on the KL-4 and click “Program Unit” in the MPS software. The ACK LED on the KL-4 will faintly flash if
programmed successfully.
KL-4 Reading: Plug the board onto the KL-4 connector labeled as “P4”. Push and hold the power button on the
KL-4 and click “Read Unit” in the MPS software.

4
Switch Mode: Select whether the switch being used for mode selection is a momentary or latched switch.
Power Up State: Select the mode you wish the scrambler to go into upon power up.
Clr/Scr Polarity: If +/- is selected then the clear mode will be a positive polarity and scramble mode will be a
negative polarity. If -/+ is selected then the clear mode will be a negative polarity and scramble mode will be a
positive polarity.
Code 1-16: Set the desired inversion frequency for each code position. The table on the previous page shows
which code is selected based upon which 4-line binary inputs are selected. If only one code is being used,
program that code in Code 16 and do not connect any of the 4-line binary inputs.

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HARDWARE INSTALLATION
Be certain to follow standard anti-static procedures when handling any of Midian’s products.
P1-4 – Black – Ground – Connect to the nearest ground point.
P1-2 – Red - +3.7 – 15 VDC – Connect to switched B+ in the radio.
P1-6 – Orange – RX Input – Connect after the CTCSS high-pass filter in radios using CTCSS or DCS. Failure to
do so will cause the CTCSS to be inverted from a low to a high frequency. Other signaling tones that might be
used on the system should be decoded before the scrambler input. The audio path should be broken with this
lead connected to the break point closest to the discriminator.
P1-13 – Violet – RX Output – Connect to the break point described in the RX Input on the side closest to the
speaker.
P1-9 – White – TX Input – Connect to the radio modulator circuit before the insertion point for CTCSS or other
tone signaling. The audio path is broken and this lead is connected to the break point closest to the microphone.
P1-1 – Green – TX Output – Connect to the break point described in TX Input on the side closest to the
modulator.
P1-7 – Yellow – PTT Input – Selection of the RX or TX path is provided via this lead. A ground from the PTT
switch will select TX & releasing the ground will select RX.
P1-3 – Brown – Mode Input/Program Out – Connect to a momentary or latched switch for selection of scramble
or clear modes. For program out, connect this lead to the yellow clip lead from the KL-3.
P1-5 – Blue – Program In – Connect this wire to the green clip lead from the KL-3.
P1-8 – Green/White – Frequency Select A – Frequency select A, B, C and D are used to determine the selected
inversion frequency (see Table 1 above).
P1-10 – Gray/White – Frequency Select B – Frequency select A, B, C and D are used to determine the selected
inversion frequency (see Table 1 above).
P1-11 – Gray – Frequency Select C or Mode LED – Frequency select A, B, C and D are used to determine the
selected inversion frequency (see Table 1 above).
When used for Mode LED install R-34 and remove D4. Connect this wire to the cathode of the LED and connect
the anode of the LED to V+. The Mode LED output provides an active low.
P1-12 – Orange/White – Frequency Select D or Audio Enable – Frequency select A, B, C and D are used to
determine the selected inversion frequency (see Table 1 above).
When used for Audio Enable install R-36 and remove D-3. Connect this wire to a point in the radio that when
grounded turns on the audio amplifier.
Mode LED: If the frequency select lines are being used for inversion frequency selection, the Mode LED hole can
have a wire added. Connect this wire to the cathode of the LED and connect the anode of the LED to V+. The
Mode LED output provides an active low.
Audio Enable: If the frequency select lines are being used for inversion frequency selection the Audio Enable
hole can have a wire added. Connect this wire to a point in the radio that when grounded turns on the audio
amplifier.

6
RADIO PROGRAMMING
The VPU-12A is a generic module that wires into most radios. Any radio specific programming, if available, would
be found on any Application Notes available for those radios. You may visit our website or call us for application
notes.
HARDWARE ALIGNMENT
The VPU-12A is a unity gain device. If for some reason more or less gain is needed adjust R-2, R-12, R-18 or R-
19 as needed. For the TX Input, Midian recommends having 1 V p-p at Pin 1 of IC-5. Adjusting R-2 will adjust the
level at Pin 1 of IC-5.
For the RX Input, Midian recommends having 1 V p-p at Pin 7 of IC-5. Adjusting R-12 will adjust the level at Pin 7
of IC-5.
For the TX Output, Midian recommends matching the level of the radio that is present at the TX Input (P1-9).
For the RX Output, Midian recommends matching the level of the radio that is present at the RX Input (P1-6).

7
OPERATION
Mode Selection: The mode of the VPU-12A can be controlled by a momentary or latched switch.
Latched Switch: Programming the VPU-12A to latched with a Mode Polarity of +/- will cause the scrambler to
be in clear mode when high and scramble mode when taken to ground. A Mode Polarity of -/+ will cause the
scrambler to be in clear mode when taken to ground and scramble mode when high.
Momentary Switch: Programming the VPU-12A to momentary with a Mode Polarity of +/- will cause the
scrambler to toggle modes when taken to ground. A Mode Polarity of -/+ will cause the scrambler to toggle
modes when taken high.
Code Selection:
Single Code: If only a single inversion frequency is desired connect the frequency select lines to ground as
indicated in Table 1 above. Otherwise if no frequency select lines are grounded code 16 will be selected.
Multi-Code: The VPU-12A has a 4-line binary input that can be used to select from 16 different inversion
frequencies (see Table 1 above).

8
TECHNICAL NOTES
Pre-emphasis/De-emphasis: The scrambler should be installed before pre-emphasis and after de-emphasis.
If installed after pre-emphasis and before de-emphasis, the recovered audio may be noisier due to the
amplification of the noise.
If installed before pre-emphasis and before de-emphasis, recovered audio will be de-emphasized (bassy).
If installed after pre-emphasis and after de-emphasis, recovered audio is pre-emphasized (tinny).
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: HUwww.midians.comU

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CP
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2007-07-01 DML
2013-04-05
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MIDIAN ELECTRONICS, INC.
DATE:
DESIGN:
DWN BY:
REV:
APPR
COPYRIGHT ©
REV
SHEET PROJECT NUMBER
DOCUMENT NAME
SCHEMATIC
2013
VPU-12A
47K
R8
47K
R1
SD1
D1
3.3V
3.3V
RA2
1
RA3
2
TOCK1
3
MCRL
4
VSS
5
VSS
6
RB0
7
RB1 8
RB2 9
RB3 10
RB4 11
RB5 12
RB6 13
RB7 14
VDD 15 VDD 16
OSC2
17
OSC1
18
RA0 19
RA1 20
16LF818
IC1
TP3
560p
C11
100K
R21
100K
R2
560p
C29
.1u
C13
-
+
2
3
1
LMV324
IC5:1
-
+
6
5
7
LMV324
IC5:2 -
+
9
10
8
LMV324
IC5:3
-
+
13
12
14
LMV324
IC5:4
4
VCCVCC
11
GNDGND
LMV324
IC5:5
VAN
560p
C12
100K
R20
100K
R12
.1u
C14
VAN
A
11
A
11
X0
12 X0 12
X1
13 X1 13 X14
X14
4053
IC2:1
B
10
B
10
Y1
1Y1 1
Y0
2Y0 2Y15
Y15
4053
IC2:2
C
9
C
9
Z
4Z 4Z0 5
Z0 5
Z1 3 Z1 3
E\
6
E\
6
VCC
16
VCC
16
VEE
7VEE 7GND
8GND 8
4053
IC2:3
SD1
D2
BSS
Q2
560p
C3
18K
R13
12K
R14
.012u
C10
BSS
Q1
-
+
2
3
1
LMV358
IC3:1
-
+
6
5
7
LMV358
IC3:2
8
VCCVCC
4
GNDGND
LMV358
IC3:3
10K1%
R15
47K
R10
36K
R11
.001u
C9
10K1%
R16
.01u
C6
.01u
C4
100p
C22
SD1D3
SD1D4
SD1D6
SD1D5
BSS
Q3
BSS
Q4
47K
R33
330R
R37
3.3V TP1
MODE LED
*
R34
BSS
Q5
.1u
C28
220K
R35
*
R36
TP2
AUDIO EN
SHDN 7
V+ 4
CLK 8
IN
2OUT 5
COM
1
OS
6
V-
3
7427
IC4
.1u
C16
.1u
C15
VAN
.01u
C19
3.3V
.1u
C18
3.3V
47K
R23
3.3V
100K
R18
100K
R19
100K
R32
.01u
C25
4.7K
R30 220K
R31
.01u
C7
560p
C27
100K
R22
VAN
.1u
C1
VAN
560p
C26
100K
R17
.1u
C2
*
C30
5206
IN1
1
ENA
3
GND
2RES 4
OUT 5
VR1
.1u
C8
.1u
C17
3.3V
3.3V3.3V
TX OUT[GRN]
P1:1
+3.7V to +15V[RED]
P1:2
CLR/SCR/PROG OUT[BRN]
P1:3
GND
P1:4
PROG IN[BLUE]
P1:5
RX IN[ORG]
P1:6
RX/TX[YEL]
P1:7
FS A[GRN/WHT]P1:8
TX IN[WHT]
P1:9
FS B[GRAY/WHT]P1:10
FS C/MODE LED[GRAY]P1:11
FS D/AUDIO EN[ORG/W]P1:12
RX OUT[VIO]
P1:13
.01u
C21
3.3V
10 MHz.
Y1
1K
R3
OSC1
OSC2
OSC1
OSC2
22p
C23
22p
C24
.01u
C20
VIN
VIN
FREQUENCY SELECT
**
***
** = TO USE MODE LED REMOVE D4 AND INSTALL R34
*** = TO USE AUDIO EN REMOVE D3 AND INSTALL R36
* = NOT INSTALLED
PIC101 PIC102
COC1
PIC201 PIC202
COC2
PIC301
PIC302
COC3
PIC401
PIC402
COC4
PIC601
PIC602
COC6
PIC701
PIC702
COC7
PIC801
PIC802
COC8
PIC901PIC902
COC9
PIC1001
PIC1002
COC10
PIC1101 PIC1102
COC11
PIC1201PIC1202
COC12
PIC1301 PIC1302
COC13
PIC1401PIC1402
COC14
PIC1501
PIC1502
COC15
PIC1601
PIC1602
COC16
PIC1701
PIC1702
COC17
PIC1801
PIC1802
COC18
PIC1901
PIC1902
COC19
PIC2001
PIC2002
COC20
PIC2101
PIC2102
COC21
PIC2201
PIC2202
COC22
PIC2301
PIC2302
COC23
PIC2401
PIC2402
COC24
PIC2501
PIC2502
COC25
PIC2601PIC2602
COC26
PIC2701 PIC2702
COC27
PIC2801
PIC2802
COC28
PIC2901
PIC2902
COC29
PIC3001
PIC3002
COC30
PID101PID102
COD1
PID201PID202
COD2
PID301 PID302
COD3
PID401 PID402
COD4
PID501 PID502
COD5
PID601 PID602
COD6
PIIC101
PIIC102
PIIC103
PIIC104
PIIC105 PIIC106
PIIC107
PIIC108
PIIC109
PIIC1010
PIIC1011
PIIC1012
PIIC1013
PIIC1014
PIIC1015 PIIC1016
PIIC1017
PIIC1018
PIIC1019
PIIC1020
COIC1
PIIC2011
PIIC2012
PIIC2013
PIIC2014
COIC2:1
PIIC201
PIIC202
PIIC2010
PIIC2015
COIC2:2
PIIC203
PIIC204
PIIC205
PIIC206
PIIC207
PIIC208
PIIC209
PIIC2016
COIC2:3
PIIC301
PIIC302
PIIC303
COIC3:1 PIIC305
PIIC306
PIIC307
COIC3:2
PIIC304
PIIC308
COIC3:3
PIIC401
PIIC402
PIIC403
PIIC404
PIIC405
PIIC406
PIIC407PIIC408
COIC4
PIIC501
PIIC502
PIIC503
COIC5:1
PIIC505
PIIC506
PIIC507
COIC5:2
PIIC508
PIIC509
PIIC5010
COIC5:3
PIIC5012
PIIC5013
PIIC5014
COIC5:4
PIIC504
PIIC5011
COIC5:5
PIP101
COP1:1
PIP102
COP1:2
PIP103
COP1:3
PIP104
COP1:4
PIP105
COP1:5
PIP106
COP1:6
PIP107
COP1:7
PIP108
COP1:8
PIP109
COP1:9
PIP1010
COP1:10
PIP1011
COP1:11
PIP1012 COP1:12
PIP1013
COP1:13
PIQ10D
PIQ10G
PIQ10S
COQ1
PIQ20D
PIQ20G
PIQ20S
COQ2
PIQ30D
PIQ30G
PIQ30S
COQ3
PIQ40D
PIQ40G
PIQ40S
COQ4
PIQ50D
PIQ50G
PIQ50S
COQ5
PIR101
PIR102
COR1
PIR201 PIR202
COR2
PIR301 PIR302
COR3
PIR801
PIR802
COR8
PIR1001 PIR1002
COR10
PIR1101PIR1102
COR11
PIR1201 PIR1202
COR12
PIR1301PIR1302
COR13
PIR1401 PIR1402
COR14
PIR1501PIR1502
COR15
PIR1601 PIR1602
COR16
PIR1701PIR1702
COR17
PIR1801 PIR1802
COR18
PIR1901 PIR1902
COR19
PIR2001PIR2002
COR20
PIR2101 PIR2102
COR21
PIR2201 PIR2202
COR22
PIR2301
PIR2302
COR23
PIR3001
PIR3002
COR30
PIR3101
PIR3102
COR31
PIR3201 PIR3202
COR32
PIR3301
PIR3302
COR33
PIR3401
PIR3402
COR34
PIR3501
PIR3502
COR35
PIR3601
PIR3602
COR36
PIR3701PIR3702
COR37
COtb0sch1
PITP101
COTP1
PITP201
COTP2
PITP301
COTP3
PIVR101
PIVR102
PIVR103
PIVR104
PIVR105
COVR1
PIY101
PIY102
COY1

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