Electronic Transmitter Guide
Help You for Building Your Own AM, FM and TV Transmitters - RF Transmitter Technical Guide
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TV RF Power Amplifier 14W #2
2009-11-27 23:07:06
From #1 TV RF Power Amplifier 14W BIAS CIRCUIT Below is the RF power amplifier's components part list and bias circuit for supply feeding. C1, C2, C4, C5, C6 = 1nF LCC Chip + 10nF LCC Chip C3 = 100µF Sprague C7 = 10µF Sprague D1 = 1N 4001 L1, L2 = 5 Turns , Diameter 0.5 mm, W Diameter 3mm P1 = 1k. R1 = 56 ohm/ 1/2W R2 = 5600 ohm, 1/2W R3 = 2.2 ohm, 3W R4, R5 = 56 ohm, 1W R6 = 4,7 ohm, 1/2W T1 : BDX 54 B/BD139 Printed Circuit Board you can Click image for enlarge and see more deatil of printed circuit board and component layout. See more : PLL Transmitter - Audio Video RF Modulator - UHF TV Power Amplifier
2009-11-27 23:07:06
From #1 TV RF Power Amplifier 14W BIAS CIRCUIT Below is the RF power amplifier's components part list and bias circuit for supply feeding. C1, C2, C4, C5, C6 = 1nF LCC Chip + 10nF LCC Chip C3 = 100µF Sprague C7 = 10µF Sprague D1 = 1N 4001 L1, L2 = 5 Turns , Diameter 0.5 mm, W Diameter 3mm P1 = 1k. R1 = 56 ohm/ 1/2W R2 = 5600 ohm, 1/2W R3 = 2.2 ohm, 3W R4, R5 = 56 ohm, 1W R6 = 4,7 ohm, 1/2W T1 : BDX 54 B/BD139 Printed Circuit Board you can Click image for enlarge and see more deatil of printed circuit board and component layout. See more : PLL Transmitter - Audio Video RF Modulator - UHF TV Power Amplifier
TV RF Power Amplifier 14W #1
2009-11-27 23:06:43
This RF power amplifier works in frequency 470 - 860 MHz UHF Band IV and V with power out 14 Watts with input power 1.5 Watts. The power amplifier is suitable for amplifying rf signal your tv transmitter with 0.5 - 2 watts power output. TV Power Amplifier Schematic RF power amplifier circuit is taken from Philips transistor application note, as you can see below. Part Lists: C1 = C6 = C16 = 4,7 pF (500 V) multilayer ceramic chip capacitor C2 = C3 = C20 = C21 = 33 pF multilayer ceramic chip capacitor C4 = C9 = C13 = C19 = 1,2 to 3,5 pF film dielectric trimmer C5 = C7 = C15 = C17 = 100 nF multilayer ceramic chip capacitor C8 = C10 = C11 = C12 = 220 pF multilayer ceramic chip capacitor C14 = C18 = 6,8 mF/40 V solid aluminium electrolytic capacitor C22 = C23 = 1 pF (500 V) multilayer ceramic chip capacitor L1 = L2 = L13 = L14 = Coax. 50 Ohm with diameter 2,2 mm; lenght 29,0 mm, soldered on striplines 75 W (1,1 mm ´ 28,0 mm). inner L1 dan L13 not connected L3 = L4 = 52 W stripline (
2009-11-27 23:06:43
This RF power amplifier works in frequency 470 - 860 MHz UHF Band IV and V with power out 14 Watts with input power 1.5 Watts. The power amplifier is suitable for amplifying rf signal your tv transmitter with 0.5 - 2 watts power output. TV Power Amplifier Schematic RF power amplifier circuit is taken from Philips transistor application note, as you can see below. Part Lists: C1 = C6 = C16 = 4,7 pF (500 V) multilayer ceramic chip capacitor C2 = C3 = C20 = C21 = 33 pF multilayer ceramic chip capacitor C4 = C9 = C13 = C19 = 1,2 to 3,5 pF film dielectric trimmer C5 = C7 = C15 = C17 = 100 nF multilayer ceramic chip capacitor C8 = C10 = C11 = C12 = 220 pF multilayer ceramic chip capacitor C14 = C18 = 6,8 mF/40 V solid aluminium electrolytic capacitor C22 = C23 = 1 pF (500 V) multilayer ceramic chip capacitor L1 = L2 = L13 = L14 = Coax. 50 Ohm with diameter 2,2 mm; lenght 29,0 mm, soldered on striplines 75 W (1,1 mm ´ 28,0 mm). inner L1 dan L13 not connected L3 = L4 = 52 W stripline (
Ring Circular Polarized Antenna for 88-108 MHz
2009-11-27 23:03:31
This simple antenna called Ring Circular Polarized Antenna. You should construct this antenna with .5 inch copper. With a little experiment I did, antenna can be tuned in 88-108 MHz FM frequency range with only changing the vertical elements. The secret is a ratio of vertical and horizontal dimensions. In FM transmitter you need signal transmitted to any direction so you need antenna type that transmitted with polarized circularly. Antenna Gain -3.2 dB, bandwith 500 KHz with maximum power handling 500 Watts. In order to use antenna on 88-108 MHz, broadband antenna type must be designed with no tune involved. How to double Your Transmitter Power Amplification of signal to transmit based on antenna gain in Decible. Power from transmitter be able to doubled, tripled or even become more power. The value is called ERP (Emmittion Radiating Power). For Doubled your transmitter power to be ERP Power need stacked 4 antennas (3.12 dB gain antenna), 6 antennas (5.12 dB), 8 antennas (6.4 dB)
2009-11-27 23:03:31
This simple antenna called Ring Circular Polarized Antenna. You should construct this antenna with .5 inch copper. With a little experiment I did, antenna can be tuned in 88-108 MHz FM frequency range with only changing the vertical elements. The secret is a ratio of vertical and horizontal dimensions. In FM transmitter you need signal transmitted to any direction so you need antenna type that transmitted with polarized circularly. Antenna Gain -3.2 dB, bandwith 500 KHz with maximum power handling 500 Watts. In order to use antenna on 88-108 MHz, broadband antenna type must be designed with no tune involved. How to double Your Transmitter Power Amplification of signal to transmit based on antenna gain in Decible. Power from transmitter be able to doubled, tripled or even become more power. The value is called ERP (Emmittion Radiating Power). For Doubled your transmitter power to be ERP Power need stacked 4 antennas (3.12 dB gain antenna), 6 antennas (5.12 dB), 8 antennas (6.4 dB)
FM Stereo Encoder for Beginner
2009-11-27 23:03:01
This circuit is a simple fm stereo encoder. A method commonly used in (double side-band suppressed carrier) DSB-SC modulation to provide synchronisation between modulator and demodulator is to transmit a sinusoidal tone (pilot tone) whose frequency and phase are related to the carrier frequency. This tone is positioned at 19 kHz, outside the pass-band of the modulated signal. The carrier frequency is 38 kHz, double that of the pilot tone. The receiver circuitry detects the pilot tone and translates it to 38 kHz, which is then used to demodulated the encoded signal. In stereo broadcasting it is necessary to transmit and receive both left (L) and right (R) audio channels while also providing the sum (L+R) to monophonic receivers. To serve both stereophonic and monophonic receivers, the (L+R) signal occupies the normal audio spectrum in the frequency range 20 Hz to 15 kHz and the (L-R) signal, also in the same frequency range, is shifted in frequency using DSB-SC modulation. The carri
2009-11-27 23:03:01
This circuit is a simple fm stereo encoder. A method commonly used in (double side-band suppressed carrier) DSB-SC modulation to provide synchronisation between modulator and demodulator is to transmit a sinusoidal tone (pilot tone) whose frequency and phase are related to the carrier frequency. This tone is positioned at 19 kHz, outside the pass-band of the modulated signal. The carrier frequency is 38 kHz, double that of the pilot tone. The receiver circuitry detects the pilot tone and translates it to 38 kHz, which is then used to demodulated the encoded signal. In stereo broadcasting it is necessary to transmit and receive both left (L) and right (R) audio channels while also providing the sum (L+R) to monophonic receivers. To serve both stereophonic and monophonic receivers, the (L+R) signal occupies the normal audio spectrum in the frequency range 20 Hz to 15 kHz and the (L-R) signal, also in the same frequency range, is shifted in frequency using DSB-SC modulation. The carri
80mW FM Transmitter with Dipole Antenna
2009-11-27 23:02:30
This electronic circuit is a fm transmitter circuit that suitable for beginners for stereo encoder testing. Provided the input stage is designed to accommodate line input levels i.e. approx. 2Vrms into 50kOhm. The transmitter output power is approx. 80mW, which is sufficient to cover an area of about one hundred meters. The RF portion consists of a totally screened oscillator which is operated by a stabilised voltage and a loosely coupled buffer stage. With this two-stage lay-out a good frequency stability and low harmonic interference radiation is achieved. The frequency of the oscillator can be adjusted in the commercial range (88-108MHz) by a trimmer capacitor Cl. The FM-modulation of the transmitter is achieved by a varicap BA138. The frequency ratio can be adjusted by the capacitor C6. To enlarge the transmission range, the output circuit which is tuned with capacitor C14, can be terminated into a full wavelength antenna. RF filters (RFC1-3) minimize power supply hum in the tr
2009-11-27 23:02:30
This electronic circuit is a fm transmitter circuit that suitable for beginners for stereo encoder testing. Provided the input stage is designed to accommodate line input levels i.e. approx. 2Vrms into 50kOhm. The transmitter output power is approx. 80mW, which is sufficient to cover an area of about one hundred meters. The RF portion consists of a totally screened oscillator which is operated by a stabilised voltage and a loosely coupled buffer stage. With this two-stage lay-out a good frequency stability and low harmonic interference radiation is achieved. The frequency of the oscillator can be adjusted in the commercial range (88-108MHz) by a trimmer capacitor Cl. The FM-modulation of the transmitter is achieved by a varicap BA138. The frequency ratio can be adjusted by the capacitor C6. To enlarge the transmission range, the output circuit which is tuned with capacitor C14, can be terminated into a full wavelength antenna. RF filters (RFC1-3) minimize power supply hum in the tr
Stereo Compressor Limiter with Clipper for FM Broadcast
2009-11-27 22:59:26
This application circuit is stereo audio compressor limiter with clipper for processing your FM audio signal. Limiter is a device, which weakens loud signals and intensifies silent signals. On its output there is signal with constant level. Signal clipping on the limiter output allows to increase the signal level without exceeding maximum frequency deviation limit 75 kHz. It's very suitable since preemphasis is used. Be careful if you want to buy any simple compressor/limiter board available on the market! Although a big list of features is mentioned, some of these toys have no signal overshooting protection and have no precise preemphasis with HF clipping option. With these devices it's not possible to keep loud sound AND meet the frequency deviation limit. So there is no reason why to pay for them. Circuit Schematic: Left Channel Schematic Right Channel Schematic Printed Ciruit Boards (PCB): Part list: Left channel: R1, R3 - 10k R2 - 1k R4, R5 - 1M R6 -
2009-11-27 22:59:26
This application circuit is stereo audio compressor limiter with clipper for processing your FM audio signal. Limiter is a device, which weakens loud signals and intensifies silent signals. On its output there is signal with constant level. Signal clipping on the limiter output allows to increase the signal level without exceeding maximum frequency deviation limit 75 kHz. It's very suitable since preemphasis is used. Be careful if you want to buy any simple compressor/limiter board available on the market! Although a big list of features is mentioned, some of these toys have no signal overshooting protection and have no precise preemphasis with HF clipping option. With these devices it's not possible to keep loud sound AND meet the frequency deviation limit. So there is no reason why to pay for them. Circuit Schematic: Left Channel Schematic Right Channel Schematic Printed Ciruit Boards (PCB): Part list: Left channel: R1, R3 - 10k R2 - 1k R4, R5 - 1M R6 -
Tunable Dipole Antenna For FM Broadcast
2009-11-27 22:56:30
This is a simple dipole antenna for FM broadcast. It can be tune for 88-108 MHz frequency range. It's very clear and easy to build. For more gain it can be stacked (2 or 4 antennas and used power divider for distributing RF energy). How to construct: Solder all copper pieces before attaching to the 1/2[inch] plastic T. The aluminum tubing is attached to the copper fitting with 2 self-tapping #6 screws, 1/2[inch] long, one on each side. The antenna element to which the ground side of the SO239(=PL259) is attached always points downwards. Tune the antenna by adjusting the lengt of the adjustable elements. Length in inches is equal to 2952 divided by the frequency in MHz Visit Free Radio See more : Video Modulator - PLL FM Transmitter - FM Antenna
2009-11-27 22:56:30
This is a simple dipole antenna for FM broadcast. It can be tune for 88-108 MHz frequency range. It's very clear and easy to build. For more gain it can be stacked (2 or 4 antennas and used power divider for distributing RF energy). How to construct: Solder all copper pieces before attaching to the 1/2[inch] plastic T. The aluminum tubing is attached to the copper fitting with 2 self-tapping #6 screws, 1/2[inch] long, one on each side. The antenna element to which the ground side of the SO239(=PL259) is attached always points downwards. Tune the antenna by adjusting the lengt of the adjustable elements. Length in inches is equal to 2952 divided by the frequency in MHz Visit Free Radio See more : Video Modulator - PLL FM Transmitter - FM Antenna
RF Power Amplifier 80W 2SC2782
2009-11-27 22:55:29
This is a conventional FM RF power amplifier design, using bipolar transistors in a tuned class C circuit. Thanks to the use of two stages, the amplifier can be driven to full power with less than 1 watt driving power, so that a large gain margin results in this FM transmitter. Bipolar VHF power transistors have a severe affinity for low frequency self- oscillation. To obtain stability in this amplifier, I employed several techniques, such as placing the resonances of base and collector chokes far apart, damping the chokes with resistors, using RC combinations for absorption of unwanted frequencies, using feedtrough capacitors for bypassing on the board, etc. It took some tweaking, but the amplifier ended up unconditionally stable. The impedance matching network between the two transistors calls for such a low inductance, that it would be impractical to make it with actual wire. So I used a micro stripline etched on the PCB. Also, the power and SWR sensor at the output was
2009-11-27 22:55:29
This is a conventional FM RF power amplifier design, using bipolar transistors in a tuned class C circuit. Thanks to the use of two stages, the amplifier can be driven to full power with less than 1 watt driving power, so that a large gain margin results in this FM transmitter. Bipolar VHF power transistors have a severe affinity for low frequency self- oscillation. To obtain stability in this amplifier, I employed several techniques, such as placing the resonances of base and collector chokes far apart, damping the chokes with resistors, using RC combinations for absorption of unwanted frequencies, using feedtrough capacitors for bypassing on the board, etc. It took some tweaking, but the amplifier ended up unconditionally stable. The impedance matching network between the two transistors calls for such a low inductance, that it would be impractical to make it with actual wire. So I used a micro stripline etched on the PCB. Also, the power and SWR sensor at the output was
30W VHF FM Amplifier BLF245
2009-11-27 22:54:11
This FM amplifier has been designed to take place on a heatsink microprocessor PC equipped with its fans, the advantage of this method of cooling has been selected for the fact that it is not very common and expensive. The Power out of the VHF FM amplifier can be achieved by 30 Watt. The size of the printed circuit of the amplifier will adapt quite easily to the type of heatsink as you have available, if possible, because in many cases, those of recovery, the fans have already lived and the price of a model remains very affordable. The dimensions of the circuit must be respected at best because of the presence of lines granted strip-line. These dimensions are 73 mm wide and 63 mm in height. The method of amplification is Class AB. Below is a description of mounting image. The layouts are made of carnations, but it is also possible to achieve with simple crossings "legs of resistance", for example .. The printed circuit will be achieved with double-sided glass epox
2009-11-27 22:54:11
This FM amplifier has been designed to take place on a heatsink microprocessor PC equipped with its fans, the advantage of this method of cooling has been selected for the fact that it is not very common and expensive. The Power out of the VHF FM amplifier can be achieved by 30 Watt. The size of the printed circuit of the amplifier will adapt quite easily to the type of heatsink as you have available, if possible, because in many cases, those of recovery, the fans have already lived and the price of a model remains very affordable. The dimensions of the circuit must be respected at best because of the presence of lines granted strip-line. These dimensions are 73 mm wide and 63 mm in height. The method of amplification is Class AB. Below is a description of mounting image. The layouts are made of carnations, but it is also possible to achieve with simple crossings "legs of resistance", for example .. The printed circuit will be achieved with double-sided glass epox
High Fidelity FM Stereo Modulator
2009-11-27 22:53:33
This circuit is a stereo encoder for FM transmitter. It is used for generating a high quality FM stereo multiplex signal that is suitable for driving mono FM transmitters. This version features improvements to the audio mixer stage, better gain adjustments in the audio filter stage and a rework of the multiplexer stage. When it is adjusted properly, the Rev E design produces an FM stereo signal with excellent fidelity. In addition, It is a good idea to have a stereo compressor between the signal source and the transmitter, when properly set, it can save the operator from having to "ride" the volume level between the point of good modulation and the point of distortion. This circuit does not perform pre-emphasis (high frequency boosting), a graphic equalizer in front of the compressor can be used if desired. This is a fairly high-level project, it should only be attempted by someone with a fair amount of electronics experience. A decent oscilloscope and an audio signal generator are
2009-11-27 22:53:33
This circuit is a stereo encoder for FM transmitter. It is used for generating a high quality FM stereo multiplex signal that is suitable for driving mono FM transmitters. This version features improvements to the audio mixer stage, better gain adjustments in the audio filter stage and a rework of the multiplexer stage. When it is adjusted properly, the Rev E design produces an FM stereo signal with excellent fidelity. In addition, It is a good idea to have a stereo compressor between the signal source and the transmitter, when properly set, it can save the operator from having to "ride" the volume level between the point of good modulation and the point of distortion. This circuit does not perform pre-emphasis (high frequency boosting), a graphic equalizer in front of the compressor can be used if desired. This is a fairly high-level project, it should only be attempted by someone with a fair amount of electronics experience. A decent oscilloscope and an audio signal generator are