badmiro

Prezent
Ulubiony
Wiadomość

Mężczyzna miro

widziany: 16.03.2021 23:47

dodatkowe uprawnienia

7719
137
189
744

10500 plików
186,09 GB

Ukryj opis

Foldery

100 Watt inverter circuit

6 Channel Auto Reverse Sequential Disco Running Lights

538-K Elektronicz ny odstraszacz młodzieży

Automatic solar tracking system

Dancing LEDs

Efekty gitarowe_schem aty

Elektronika Praktyczna

Fire alarm circuit

Flash

Infrared motion detector circuit

Interfejs MIDI - schematy

Ipod Stereo FM transmitter with 1W output power

Lead acid battery charger circuit

Long Range FM Transmitter 1

Mini Strobo- stroboskop z lampy blyskowej aparatu fotograficzneg o

Modelist 1964

Moj zeszyt - schematy

Mosquito repellant

Programator EPROM 2764

eprom_prog

Radio Collar Transmitter

Remote controlled appliance switch circuit

Sonic Distortion

Strobelight_12 W

Stroboskop - zarowka ksenonowa OXP15

Triple Stroboscope

VGA to SCART converter

VGA to SCART converter2

Wyciszenie komputera-ster ownik silnika 12V

Wentylator PC

Filmy

Galeria

	500 W Tweeter Boxes
	gitary

Videoclipy - do playerka ;)

zachomikowane

Ostatnio pobierane pliki

PC Camera Drivers.zip

surelabs_setup.zip

Disco Setup.exe

DMX_512_WinAmp_Light_Show_.exe

Vectric VCarve Pro 6.091.exe

mach3_CNC_+_license_(((F_U_N_Z_I_O_N_A_N_T_E_!_!_!))).zip

mach3 CNC + license.rar

kxdrv3537-full.exe

USBDMX Interface.rar

WinPCNC_37911.zip

Long Range FM Transmitter 1

Galeria

sortuj według:
nazwa
typ pliku
rozmiar
data dodania

11 KB
12 lut 10 18:03

How to make a long range FM transmitter at low cost

Description

The use of transmitters which have a more powerful output than the ‘flea-power’ are sometimes required when there are many obstacles in the path of the surveillance transmitter and monitoring station receiver, or the distance between them is too far so as to make a low powered device feasible. Whereas a typical microtransmitter will produce an RF power in the order of just a few milliwatts, i.e. a few thousandths of a watt, the VHF-FM transmitter described has a power output of between around a half and 2 watts, depending on the power source, which may be anywhere between 6 volts and 30 volts d.c. The battery or batteries should be of the alkaline high power type, since the current drain will be found to be relatively higher when compared to microtransmitter current drain. The power output of this device is somewhat proportional to the current drain and so therefore both may be decreased by altering the value of R6 to a higher resistance, or a variable resistor with a value of around 1k may be introduced in series with the existing R6, so as to give a variable power output. The variable resistor must not be a wirewound device because this would act as an inductor which will cause feedback problems.The audio input to the power oscillator, which incidentally is formed by TR2 and associated components, is derived from a piezoelectric microphone which drives the simple audio frequency amplifier TR1. The input of the audio amplifier is controlled by the gain pot R1, which selects the correct amount of voltage that is generated by the piezoelectric microphone, then connects this signal to the base of audio amplifier TR1 via C7. It may be found that there is insufficient housing space for a bulky piezoelectric microphone, so with a slight modification to the circuit, it is possible to employ an electret microphone insert as shown. Since the RF field that is generated by this transmitter is relatively large, the problem of RF feedback may very well be encountered. This may be overcome by placing the transmitter inside a metal enclosure, keeping all internal wiring as short as possible and the aerial wire.
Component listing for 1 watt transmitter

Resistors Semiconductors R1 = 27k TR1 = BC547 R2 = 330k TR2 = 2N2219 fitted with heatsink R3 = 5k6 MIC = piezoelectric microphone R4, 5 = 10k R6 = 100R

L = 6 turns 22 gauge enamelled wire wound on 3⁄16″ former

Capacitors

C1, 2, 3, 8 = 330 pF C4 = 2–10 pF trimmer C5 = 4p7 C6 = 1 nF

C7,C8 = 40uF/25V Electrolytic

Pobierz folder
Zachomikuj folder

1 plików
11 KB

bezpośredni link do folderu

Chomikowe rozmowy

Tiili napisano 23.06.2017 21:28

Witam, pozdrawiam i zapraszam do mnie Filmy, ciekawe Filmy Dokumentalne, Seriale, TV Show, Książki, Artykuły, Teledyski, Tapety, Emotki i wiele innych. obrazek