Posted on Sunday, September 16, 2012 • Category: FM Transmitters
Here is a simple USB FM transmitter that could be used to play audio files from an MP3 player or computer on a standard VHF FM radio by connecting it to an USB port. The circuit use no coils that have to be wound. This USB transmitter can be used to listen to your own music throughout your home. To keep the fm transmitter circuit simple as well as compact, it was decided to use a chip made by Maxim Integrated Products, the MAX2606. This IC from the MAX2605-MAX2609 series has been specifically designed for low-noise RF applications with a fixed frequency. The VCO (Voltage Controlled Oscillator) in this IC uses a Colpitts oscillator circuit. The variable-capacitance (varicap) diode and feedback capacitors for the tuning have also been integrated on this chip, so that you only need an external inductor to fix the central oscillator frequency.
Posted on Monday, August 20, 2012 • Category: FM Transmitters
This easy to build FM transmitter bug can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Transmitter frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the fm transmitter bug with a 9Volt Battery, or you can plug a power supply to feed in 9-12 Volts. That bug will pick even a low whisper or even the sound of a breath well far from the microphone. Great spy transmitter equipment.
Posted on Saturday, June 23, 2012 • Category: FM Transmitters
After building FM transmitter I decided to build a 6W RF Transmitter amplifier for the FM band to get more power and we chose to copy a 6 Watt design built around 2SC1971 RF power transistor. We were not satisfied with finished result and decided to replace the fixed capacitors around the pcb inductors with variable capacitors, this is much better and possible to tune to your transmitter frequency.
Posted on Friday, June 15, 2012 • Category: Antennas
This HD TV UHF wideband amplifier(Ultra High Frequency amplifier) has a total gain of 10 to 15 dB in the 400 – 850 MHz domain frequency so it can be used where the tv signal is weak.
For this UHF antenna tv amplifier to work correctly you need to cut the components pins as short as possible. C1, C2, C6, C7 are SMD type ( surface mounted ). This antenna tv amplifier or uhf wideband amplifier need to be build inside of a metal box and then connected close to the tv antenna.
Posted on Sunday, June 10, 2012 • Category: Amplifiers
Single Ended Valve Triode Amplifier has not same tone with Push Psu Amplifier. Over 90% of Amplifiers are push pull, and push pull amplifier does not 2nd harmonic and off course
does not get 2nd 4th, 6th harmonic vs SE has 2nd, 4th, 6th harmonic. Push pull has minor distortion than SE Amplifier.2nd harmonic is make good tone for Music.not too much and not less than.feel good sound get from Single Ended Amplifiers with high efficiency speakers from 88dB/m to 100dB/m. I means Single Ended Amplifier
is almost Single Ended Triode Amplifier.or Penthode but wired Triode. Tone is Different.good for Jazz and
small room Classic.
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