4 man boat £21
£9 tent
6v 100AH £28ea
New RF modulators/video senders in stock.
Allows a camcorder,cctv module or other device with AV output to transmit to a standard television. Preset to channel 36 the units have a video in socket, audio in and TV aerial out socket. Power requirement is 4.5-15v DC 25mA or PP3 internal battery (not included) Designed to connect together the unit and TV using the supplied cable but would probably work well with UHF aerials for wireless transmission.105x60x25mm.
XXXX-KEEMOD1
Video Sender Kit
Just in are these new video sender kits, please note that it is not illegal to own or build but once completed it may well be illegal to own one.
Click
image to enlarge details
A/V SENDER KIT
This kit provides you with wireless audio and visual transmission to a TV. The TV acts as a receiver, eliminating the need to buy a separate monitor. You can also hook it up to a VCR or a CCD Camera, and even set up a remote CCTV security system!
XXXX-VSXX2
Circuit Analysis:
Q3 VC 1 ~ C 13, C 16 and 13 all make up a colpitts oscillator circuit that fluctuates from 22O~25O MHz. You can regulate the frequency to any value within this threshold by tuning VC I or 13. C 13 modulates the signal rate. When the capacitance increases, so does the modulation. R9 and C 16 bias the local oscillation. If we lower R9’s frequency to 68OR the oscillator’s output level will increase.
Q2 and L2 act as a frequency doubler. C7, along with FCZ783R5 (IF Trans former), the Q4 transistor, C14, C19 and R12 all make up the mixer. This mixer takes both audio and visual signals together and "mix" them into one and passes through RF Amplifier Q I to transmit the signal to the antenna.
Testing:
1: Turning the blue component’s trimmer on VC 1 varies the frequency. When we turn the trimmer, the television’s channel has to be changed accordingly. It is easier to tune the A/V Sender if you have a spectrum analyser to help you find the correct frequencies. If the frequency is tuned to 474 MHz, then this would be the equivalent of your TV’s channel 14 UHF band.
2: The IF Transformer Is used to synchronise the audio and video frequency’s level ratio. If the TV’s image is too blurry then you can adjust the IFT to fine-tune the image.
3: SVR1 controls the video signal input ratio~ while SVR2 controls the audio portion. You can tune these components according to your needs.
Parts List:
Resistors 5% 1/8W
68R R1
4.3K R2
1K R3.R9,R15
6.8K R4,R7
2.2K " R5
560 R6
5.6K R8
470 R1O,R12
270K " R11
100 R13
10K R14,R17
1M R16
Capacitors:
2P (NPO) 2.54mm Cl, C2
22P (NPO) C3
103 C4,C8,C17
102 C9, C10, C15, C20
104 C21
3P (NPO) C11
12P (NPO) C6
470P C23
5P (NPO) C7,C13
47P (NPO) C16.C19
lOOP (NPO) C14,C18
220uF/16V (6Xllmm) CS
4.7uF/16V(4x7mm) C12, C22
lOuF/16V C24
Transistors:
2SC2369 or 2SC3358 Q1
2SC1674 Q2,Q3
2SC945 Q4, QS
Diodes:
Zener 11V/, 1/4W Dl
5V, D2(or 5.1V)
3V, D3(or 5.1V)
60-2
SVR1 1K/6mm (3 pin) SVR2 1OK/6mm(3 pin)
VCl / SP/ 6mm(2 pin)
LI d=3mm D=4mm O.7mm, 2T
.L2,L3 3T
End of parts list
Click
image to enlarge circuit diagram
Click image to enlarge
pcb layout
Complete kit excluding aerial and psu but including all components,
PCB and a case is
XXXX-VSXX2
