Velleman K4601 User manual
1
AUDIO / VIDEO MODULATOR
K4601
ILLUSTRATED ASSEMBLY MANUAL H4601IP-2
Total solder points: 131
Difficulty level: beginner 12345 advanced
Convertanaudioandvideosignalintoa
UHFTVsignal.
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3
If it is desired to connect a video signal originating from a camera or other video source to a normal TV set, you will need this
modulator. The audio and video signal is converted into a UHF TV signal so that the signal can be received through the TV
antenna input. In certain countries (find out from your national telecommunications authority) it is permitted to use this
modulator as a mini-transmitter by connecting a small antenna to it. With this facility it is possible to receive the signal from
the video recorder or camera elsewhere within your home (range 30m, 98' approx.). The kit comes complete with housing
and antenna connector.
Specifications :
Input: audio and video.
Output: UHF channel 21 (450 - 500MHz adjustable).
Power supply: 12 to 15VDC / 100mA.
Dimensions: 70 x 104 x 30mm (2.8" x 4.1" x 1.2").
Features & Specifications
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Assembly hints
1. Assembly (Skipping this can lead to troubles ! )
Ok, so we have your attention. These hints will help you to make this project successful. Read them carefully.
1.1 Make sure you have the right tools:
• A good quality soldering iron (25-40W) with a small tip.
• Wipe it oftenon a wet sponge or cloth, to keep it clean; then apply solder to the tip, to give it a wet look. This is called ‘thinning’ and will
protect the tip,and enables you to makegood connections. When solder rolls off the tip, it needs cleaning.
• Thin raisin-core solder. Do not use any flux or grease.
• A diagonal cutter to trim excess wires. To avoid injury when cutting excess leads, hold the lead so they
cannot fly towards the eyes.
• Needle nose pliers, for bending leads, or to hold components in place.
• Small blade and Phillips screwdrivers. A basic range is fine.
For some projects, a basic multi-meter is required, or might be handy
1.2 Assembly Hints :
⇒ Make sure the skill level matches your experience, to avoid disappointments.
⇒ Follow the instructions carefully. Read and understand the entire step before you perform each operation.
⇒ Perform the assembly in the correct order as stated in this manual
⇒ Position all parts on the PCB (Printed Circuit Board) as shown on the drawings.
⇒ Values on the circuit diagram are subject to changes.
⇒ Values in this assembly guide are correct*
⇒ Use the check-boxes to mark your progress.
⇒ Please read the included information on safety and customer service
* Typographical inaccuracies excluded. Always look for possible last minute manual updates,indicated as ‘NOTE’ ona separate leaflet.
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Assembly hints
1.3 Soldering Hints :
1- Mount the component against the PCB surface and carefully solder the leads
2- Make sure the solder joints are cone-shaped and shiny
3- Trim excess leads as close as possible to the solder joint
REMOVE THEM FROM THE TAPE ONE AT A TIME !
AXIAL COMPONENTS ARE TAPED IN THE CORRECT
MOUNTING SEQUENCE !
You will find the colour code for the resistances and the LEDs in the HALG
(general manual) and on our website: http://www.velleman.be/common/service.aspx
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R2 : 100 (1 - 0 - 1 - B)
R3 : 560 (5 - 6 - 1 - B)
R4 : 1K (1 - 0 - 2 - B)
R5 : 1K (1 - 0 - 2 - B)
R6 : 1K (1 - 0 - 2 - B)
R7 : 10K (1 - 0 - 3 - B)
R8 : 1K5 (1 - 5 - 2 - B)
R9 : 1K5 (1 - 5 - 2 - B)
R10 : 1K5 (1 - 5 - 2 - B)
R11 : 2K7 (2 - 7 - 2 - B)
R12 : 2K7 (2 - 7 - 2 - B)
R13 : 2K7 (2 - 7 - 2 - B)
R14 : 5K6 (5 - 6 - 2 - B)
R15 : 270K (2 - 7 - 4 - B)
3. 1/4W Resistors
R...
Construction
ZD1 : 11V
ZD2 : 6V2
1. Zener diodes. Watch the
polarity !
ZD1
CATHODE
C1 : 3pF (3.3)
C2 : 3pF (3.3)
C3 : 3pF (3.3)
C4 : 1pF (1, red)
C5 : 3pF (3.3)
C6 : 10pF(10)
C7 : 15pF(15)
C8 : 22pF(22)
C9 : 33pF(33)
C10: 56pF (56)
C11: 100pF (101)
C12: 100pF (101)
c...
5. Capacitors
R1 : 47 (4 - 7 - 0 - B - 9)
2. 1/2W Resistor
R...
L5 : 10µH(1 - 0 - 0 - A)
4. Choke.
L...
L...
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Construction
RV1 : 50K (47K)
RV2 : 1K
7. Trim potentiometer
RV1
CV1 : 5pF
6. Trim capacitor
CV...
C13 : 180pF (181)
C14 : 470pF (471)
C15 : 1nF (102)
C16 : 1nF (102)
C17 : 1nF (102)
C18 : 1nF (102)
C19 : 1nF (102)
Cut 3 lengths of the 0.6mm wire supplied to the exact length.
Scrape the enamel off the ends of each length of wire with a sharp
knife for about 5 mm and tin the ends.
Make up the windings on a gimlet of 3.5mm diameter.
L1 : 3 turns Cu 0,6mm (!) - Fig 1.0
3 windings close together
L2 : 3 turns Cu 0,6mm (!) - Fig 2.0
3 windings approx 2mm from
each other (see PCB surface)
L3 : 2 turns Cu 0,6mm (!) - Fig 3.0
2 windings close together
8. High frequency inductors
3,5mm
Ø 3,5mm
Ø
3,5mm
2mm
8
T1 : BC547B
T2 : MPSH10
T3 : MPSH10
9. Transistors
T1
Construction
SW1 : TS - 8
SW...
J4 : DJ-005
11. DC-jack
10. Switch.
J1 : Audio
J2 : Video
12. RCA connectors
J...
C20 : 4µ7
C21 : 4µ7
C22 : 10µF
C23 : 10µF
C24 : 220µF
13. Electrolytic Capacitors.
Watch the polarity !
C...
L4 : 10,7MHz
14. High frequency
transformer
J3 : RF (!)
15. Antenna connector
LD1 : Red.
Connect first the two wires to
the spots marked “c” and “a”.
16. LED. Watch the polarity!
LD...
CATHODE
2 wires
Fig 4.0
9
Construction
Insert the red LED into the housing as in the drawing.
Pay attention to the polarity!
Now connect the two wires with the pins of the LED,
respect the polarity!
Cathode
Anode
Solder them together
Fig 6.0
Fig 5.0
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T4 :BFR90
Mount the special high frequency
transistor along the soldered side,
due to length of the leads it is not
possible to mount this incorrectly.
17. High frequency transistor
Construction
Attach the sticker giving the connection information to the back of the
housing.
Mount the 3 threaded rods on the bottom of the housing, together with a
tooth lock washer and M3 countersunk-head bolts (see figure 8.0).
Mount the PCB on the threaded rods using 3 x M3 bolts.
18. Fitting inside the housing
HOUSING
6mm M3 BOLT
PCB
LOCK WASHER
8mm M3 SPACER
4mm M3 BOLT
Fig 7.0
Fig 8.0
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Preparation:
Set trimmer potentiometers RV1 (audio) and RV2 (video) to a maximum (completely clockwise).
Set the frequency trimmer capacitor, CV1, to the middle of its range.
Carefully turn the core of L4 completely down using a suitable screwdriver.
Put the housing cover into place.
Connect a video and audio signal to the inputs of the modulator
Using a cable and connectors, connect the antenna output of the modulator to the antenna input of the
TV set, or connect a 30cm length of stiff wire to the modulator antenna connector.
ATTENTION: As soon as an antenna is connected to the modulator, it becomes a transmitter
which is prohibited in some countries.
Connect a supply voltage (adaptor) of between 12 and 15 VDC to the supply voltage connector. Check
the polarity, the edge of the connector must be negative.
Set the modulator switch to ON. The control LED should now light up.
19. Test and setup
Test and setup
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Adjusting the picture:
Set the TV set to "search" on the UHF band until a clear picture is obtained. If a clear picture cannot be
obtained then try turning the trimmer capacitor to a different setting (turn 1 to 2 mm per test).
"Expand" or "compress" (see fig. 9.0) also have an influence on the picture quality, and it is always
necessary to close the housing before doing the test (if the test is done with an open housing then the
settings will probably have to be done again after the cover has been put in place).
Test and setup
Fig 9.0
L2
L2
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The modulation of the video signal can be further adjusted using trimmer potentiometer RV2.
NOTE: The above instructions for setting the received picture are only guidelines. A little
experimentation with the setting of the frequency capacitor, CV1, and also variations in inductor L2
and potentiometer RV2 can greatly improve the picture quality.
Setting the sound:
Once a good picture has been obtained the sound carrier can be set.
Carefully turn the core of L4 with a suitable screwdriver, until the background noise is suppressed and a
normal sound can be heard.
The audio modulation can be further adjusted using RV1 (with overmodulation distortion becomes
audible).
The modulator is now ready for use
Test and setup
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Diagram
20. DIAGRAM
J2
J1
J4
SW1
+
C17
C23
ZD1
C3
R10 L3
RF
C4 GND
C5
R6 T4
C9
C7
C14
RV2
C6
R13
LD1
C2
R7
C16
VCC
T2
L1
C1
CV1
VCC
ZD2
R8
C18
R12
R5
R11 C8
C10
C15
C12
T1
R9 C13
C20
RV1
R2
C22
C19
GND
GND
IN
IN R15
C21 C11
T3
L4
R3
L2
R1
R4C24
-VCC
R14
OUT
VIDEO
AUDIO
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21. PCB
PCB
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Modifications and typographical errors reserved
© Velleman Components nv.
H4601IP - 2004 - ED2
VELLEMAN Components NV
Legen Heirweg 33
9890 Gavere
Belgium Europe
www.velleman.be
www.velleman-kit.com
5410329 290412
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