The transmitter operates in the UHF range (UHF) and built on a single chip and two microwave transistors. It ensures the perfect quality color picture at a distance of about 50 m. the Maximum range depends from the sensitivity of the TV, antennas used, and for color is 300 m, and black and white - more than 500.
Schematic diagram the transmitter is shown in the figure.
Coils L1, L4, L5 contain 1.5 round (ring conclusions down) of PEV 0.5 mm, and the coil L3 2+2 turns of the same wire, and consists of two halves, between which is placed the coil L4. The gap between coils L3 and L4 of about 1 mm. Coil L2 is taken from the contour of rejection of any sound TV. The contour L2 C12 tuned to the subcarrier frequency sound 6.5 MHz, so the capacitor C12 may be another tank, which was part of the circuit TV.
Details of the transmitter is placed on the printed Board of foil on one side of the fiberglass. Schematic diagram drawn so as to easily trace the wiring a printed circuit Board. However, note that the width of the conductors must be not less than 1 mm. Conductor "mass" is solid filled free space Board, at a distance of 1-2 mm from the other conductors. It is important that the pins 5 and 14 connected with each other under the chip and with a mass the shortest way. One should strive to see the rest of the wires were the minimum length. Mandatory welds both pins of the microwave emitter transistors.
Fee top brass closes the screen height of 20...25 mm with holes opposite the adjusting elements (R7, C13, 14, 21, L2) and output antennas. Screen propivaetsya the contour of the bottom of the Board. To install the antenna on the Board raspivaetsya brass sleeve with inner thread M2, where and wrapped the probe antenna. The antenna is a a piece of bare copper wire from lighting wire cross-section 2.5 mm2. Antenna length is determined experimentally and is approximately 30 cm.
Setup is to install the point of the modulation resistor R7 (this also changes the operating frequency) the lack of green and pink contours "Tyagunov" on the image, contours and matching with the antenna. In the last turn circuit is configured on L2 frequency 6.5 MHz (on the ear for pure sound transmission). The output signal of the transmitter must have sufficient power to receive "input" of the TV from a distance about one meter.
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