An FM transmitter is a gadget that uses the standards of frequency modulation to broadcast sound provided at its input. Typically, the reflector element is 5 % longer than the driven element and the director is 5% shorter than the driven element. I think I need to build an external antenna but need to know where to hook it up to the thing. The middle element is the simple half-wave, folded dipole. 2 Cut the ½ inch casing for reflector, driven element (also called folded dipole) and the directors as per size as above. The reflector reflects RF energy and the director directs the RF energy. I would like to boost the range of the device. Say if its 1.5 meters then cut it to 2 pcs exactly from the center. Step 2: Length Detail. Halloween Pumpkin With a Moving Animatronic Eye | This Pumpkin Can Roll Its Eye. INCREASE RANGE OF SIMPLE LOW POWER FM TRANSMITTER BY YAGI ANTENNA Step 1: DESIGNING a YAGI UDA ANTENNA: (YAGI ANTENNA). 3 Run an un-insulated or enameled copper wire (shown as “straight wire” in diagram below) of say 10 to 16 SWG (used in motor winding) along the length of the boom on the top (not inside).If enameled copper wire is used then remove the enamel at the soldering joints and also for the at the 2 end points of the driven element ie the dipole. Length between reflector to dipole=43/106= 0.4 meters approx. Extremely thorough on practical power electronics & electrical. F=106 MHz as in the first diagram and the 2nd one is with 107.9 MHz: as per the following calculations, Reflector length=150/107.9=1.39 or rounded to 1.4 meters. The lengths of various antenna elements are related to the frequency. Share it with us! 14 Use any pipe to get Yagi antenna stand straight on some height while aiming the director side to the desired direction that you would like to get the range. gap between director to director = same 0.41. Now fix them at the same place where the driven element is supposed to be there. Length between reflector to dipole=43/106= 0.4 meters approx. 6 Take another wire more than the double of the driven element ie the folded dipole, 7 Join its center to the boom point wire by soldering. Using a balloon transformer would bring about a better matching impedance. One is called the director elements. gap reflector to driven=(43/107.9)=0.398-rounded to 0.4 . But maintain the gap as calculated. Antenna stacking space is 1/2 to 1 wave length Reflector length =150/f(MHz) =150/106=1.41 Meters, Driven element length =143/f(MHz) =143/106=1.35 Meters, First Director length =138/f(MHz) =138/106=1.30 Meters, Second Director length=134/f(MHz) =134/106=1.26 Meters, Length of Boom=(43/106) + (45/106) + (45 /106)= 1.25 Meters approximately. Extremely conversant with simulation software like Multisim, Circuit m…. Any obstructions in the line of sight also affect the range. Given below an example for 107.9 MHz using a small portion of the same co-axial cable as per connections seen below, 1 Get from electrical shop 1 inch wide rectangular Plastic casing ( used in house wiring), 12 feet long - 1 no, 2 Also get from any electrical shop ½ inch wide 12 feet long casings -2 nos, 3 Any pole wooden / bamboo stick /iron pipe to hold the antenna straight. Connect the co-axial cable to the driven element. Battery Powered Lamp That Turns on Through the Use of Magnets! 1. 5 Join the center points to the wire on the boom for directors ,reflector by soldering, be careful as the plastic is near by. Stacking (adding) antennas to increase antenna power gain. For omnidirectional transmission, omnidirectional antenna type will be used. B) However a standard antenna with aluminum pipes as were, used in our TV in earlier days is the best if you can get it made to order. There are two ways to increase the antenna gain. The transmitter I have is a ge FM transmitter for ipod. (I know it is illegal but would like to get more range than 2 feet.) 8 Place the plastic case meant for the dipole over the boom top now and tape to hold the wire firmly. Length between director to director=45/106 =0.425 meters approx. The other three outer elements are called parasitic elements. The above fig shows a basic yagi antenna consisting of four elements. This antenna was invented in the early 20th century by two Japanese engineers named Uda and Yagi. For good efficacy and directivity for reception on radio spectrum, we need a good Yagi-Uda antenna. It is termed the ‘driven element’ because it is only element that is directly connected to the FM transmitter, driving the entire antenna. The Yagi antenna is a narrow-band antenna designed to work only on FM channel. A) Making a simple and cheap Yagi antenna at home as explained above ,by not using aluminum pipes but plastic material and some wire , may give a range of about 1 KM for a simple transmitter that covers hardly 100 meters.The out put from the transmitter is fed to a co-axial cable (generally used for cable TV ) which nearly matches to the Yagi antenna impedance of 75 ohms for best results. About: 42 years of experience from manufacturing, R&D, based to training. For the highest gain or discriminating against an interfering signal 20deg-40 deg azimuth off the desired signal, we use a yagi antenna. Do not place the plastic case now. Did you make this project? Or buy a TV antenna whose dipole ( driven element) is bigger than 1.35 meters. The antenna parameters element lengths and spacing are given in terms of wavelength, so an antenna for a given frequency can be easily designed. To increase transmission range, the antenna gain and height must be increased for both systems. 4 Run similar wire as per the size for the directors and the reflector on the boom wire at right angles to the boom wire. 6 Get co-axial cable , as used by cable TV connection as per your need to get a good height to mount the antenna at rooftop. I bought a FM transmitter for an ipod. The cable, impedance matching, and height at which it is installed are also important. It has the best gain for its sizes and a correspondingly narrow main lobe (beam). Typical FM transmitter design’s normally comply with the block graph below. Thus make the boom about 1.5 meters. This is to be used as feeder wire from the transmitter circuit to the antenna. Add all the gaps and that will be the boom length. Basically an yagi antenna consists of one reflector (in the rear), one driven element and one or more directors (in the direction of direction/reception). No need to size the directors even if they are smaller than the design parameters. Length between dipole to director=45/106 = 0.425 meters approx. Thus the boom length= 0.4+0.41+0.41=1.22 meters. The best way to increase the range of your FM transmitter is to use a matched antenna as per the impedance without which one gets very little range coverage. FM transmitter we are going to make is long-range although you can increase more range with the help of a large antenna. Then make each pc 1.35/2 by again cutting them. 9 Fold both the ends of that dipole wire at the ends of the plastic casing and bring them at the top of the casing and tape it firmly, 10 Take out 2 ends for connection and use cello tape to keep them in firm place, 11 These 2 ends are meant for feed from the transmitter through the co-axial cable, 12 Now place the plastic casings of reflector and the 2 directors on the top of the boom over their respective wire and tape them for the wire to be sticking to the plastic case, 13 Use cello tape in cress cross way to bind the reflector ,dipole and the 2 directors on the boom firmly, to look like an olden day television antenna. gap between driven to first director=(45/107.9)=0.41. 1 Use the 1 inch plastic rectangular casing as main support ,let us call it boom (see the diagram above).