08-02-2017, 06:19 PM
14-02-2017, 12:51 PM
This Kit is a powerful 3-stage 9V (Tx) FM transmitter with a range of up to 1 kilometre outdoors. It uses one RF transistor in its output phase and two BC547 for the first two stages. The transmission distance depends critically on operating conditions (in a building or open), the type of antenna used (single cable or dipole), operating voltage (12V is better than 6V) and if the Circuit is maximum for maximum performance. The kit is built in a one-sided printed circuit board (PCB). It has a silk screen superimposed on the top to assist the construction. At the bottom there is a welding mask to assist in welding. Protel Autotrax and Schematic were used to design the dashboard.
ASSEMBLY INSTRUCTIONS
Components can be added to the PCB in any order. It is usually easier to add the lowest height components first and then proceed to the higher components. The electric microphone must be inserted with the pin attached to the metal casing connected to the negative rail (ie, to earth side or zero voltage of the circuit). This is marked with a '-' sign on the MIC in the Printed Overprint circuit. To save space, all resistors should be placed at one end. Be careful to put the transistors around the correct way. Note three points: - the two 100n capacitors of the PCB have a spacing of 0.2 "and 0.1". We have put in components with the correct spacing to facilitate the construction. - we have supplied pre-welded pre-welded wire coils of 6 and 8 turns. The legs should be welded directly to the pads of the PCB. However, pay particular attention to soldering in case all enamel has not been removed. You may need to weld or scrape more enamel from the ends of the two enamelled coils. - a connection (or tap) is required from the centre of the tinned copper wire coil L1 to the TAP marked pad next to the coil. Weld a piece of wire to the top of the middle turn as shown in the overlay. Then weld the other end to the pad immediately next to the coil L1. Extend the L1 coils approximately 1 mm or more apart. Make sure that none of the coil loops are touching the loop next to it.
ASSEMBLY INSTRUCTIONS
Components can be added to the PCB in any order. It is usually easier to add the lowest height components first and then proceed to the higher components. The electric microphone must be inserted with the pin attached to the metal casing connected to the negative rail (ie, to earth side or zero voltage of the circuit). This is marked with a '-' sign on the MIC in the Printed Overprint circuit. To save space, all resistors should be placed at one end. Be careful to put the transistors around the correct way. Note three points: - the two 100n capacitors of the PCB have a spacing of 0.2 "and 0.1". We have put in components with the correct spacing to facilitate the construction. - we have supplied pre-welded pre-welded wire coils of 6 and 8 turns. The legs should be welded directly to the pads of the PCB. However, pay particular attention to soldering in case all enamel has not been removed. You may need to weld or scrape more enamel from the ends of the two enamelled coils. - a connection (or tap) is required from the centre of the tinned copper wire coil L1 to the TAP marked pad next to the coil. Weld a piece of wire to the top of the middle turn as shown in the overlay. Then weld the other end to the pad immediately next to the coil L1. Extend the L1 coils approximately 1 mm or more apart. Make sure that none of the coil loops are touching the loop next to it.