Title: Broadcast Hardware

300W RF Power Amplifier for FM Broadcast MRF6V2300N

Published on Sun, 22 Nov 2009 17:41:00

Here's a 300 watt singleended RF power amplifier for the FM broadcast band. This broadband FM power amplifier with simplicity and reliability is possible and compact to design and build at low cost. This RF power amplifier using the low cost OMP Freescale MRF6V2300N LDMOS transistor. It operates at Vdd = 50 VDC with an average drain efficiency in excess of 60% and a gain of 24 dB with a 1 dB gain flatness over the 88-108 MHz band. No tuning is required as the amplifier is broadband. Enhanc read more..

i-mobile Wireless FM Transmitter with Remote Control

Published on Mon, 09 Nov 2009 11:36:00

This handy MP3 FM Modulator turns any USB Memory Flash Drives / Memory Cards into an MP3 player. It also has the general line-in function for other portable audio devices (e.g. iPod). It is a perfect product to fully utilize and enhance your car audio equipments. You don't have to worry about the unstable playback from the traditional CD audio player, simply download the MP3 to the Memory Card / Flash Disk, plug this Modulator to your car cigarette lighter, tune your radio to match the freque read more..

Two Way Radio-Microphone Connections

Published on Sun, 11 Oct 2009 13:28:00

Are looking for internal cable connection of your rig microphone? Here is  the right place of your choice. This site collects any info about microphone connections and sockects. If you have any Microphone information You would like to add to help other radio amateurs or two way radios. Check this out!. Kenwood Most Popular Microphone Connections If you wan to know more about your rig microphone connections or your two way radio external microphones visit this best site g4wpw read more..

RF Power Amplifier 144 MHz 50W 2N6084

Published on Fri, 09 Oct 2009 08:17:00

This RF Power Amplifier for 144-146 MHz. It uses a 2N6084 RF transistor with power output 50w max. It is a class C amplifier design, and therefore good for FM mode only. RP Power Amplifier Schematic RF Sensing Schematic Source: 2N6084 144MHz FM Power Amplifier read more..

RF Amplifier Broadband 88-108 MHz 100W

Published on Sat, 19 Sep 2009 05:31:00

This RF amplifier for FM 88-108 MHz with no tune (broadband) needed to cover all the FM Band. This RF Power amplifier is equiped with a bipolar transistor, the famous MRF317. As lots of FM amplifier application ,the power transistor is in a C class bias. All the impedance networks (Input-Output) of this RF amplifier have been determined by using the softwares: Mimp.EXE. This RF Amplifier need a 9 elements low pass filter ensures that its harmonic frequency meet at least a 60 dB rejecti read more..

RF Filter Design With AADE Version 4.4

Published on Fri, 11 Sep 2009 19:59:00

Here's a free Filter Software you can download that it will design most classical passive ladder Low-pass Filter, High-pass Filter, Band-pass Filter, and Band-Reject filters and analyze them in both the frequency and time domains. You can also enter a schematic and parts list from a book or magazine for analysis. Download AADE Filter Design DESIGN Butterworth, Chebyshev, Elliptic (Cauer), Bessel, Legendre and Linear Phase: low-pass, high-pass, band-Pass, and band-reject filters. Coupled read more..

Elliptical RF Low-Pass Filter 88-108 MHz

Published on Fri, 11 Sep 2009 19:37:00

Here's a reference circuit for building Elliptical FM Low-pass Filter (from Cauer) for Power Amplifier 88-108 MHz. A ninth-order, elliptic, low-pass filter attenuates harmonics generated in the power amplifier. The capacitors for the filter are circuit board pads. The directional coupler (reflectometer) uses printed circuit board traces for micro-strip transmission lines. Transmission line segments (with an impedance of about 82 ohms) on either side of a 50 ohm conductor provide sample vo read more..

Harmonic Absorbing Filter for FM RF Amplifier

Published on Wed, 29 Jul 2009 07:15:00

All RF amplifiers will "react" in some way when a low pass filter is attached. This reaction is mainly caused by reflected harmonics. All RF amplifers generate harmonics. When a low pass filter is attached to the amplifer most of the harmonic energy is reflected back to the transistor causing reduced efficency and output power. The transistor will also run hotter. The new LDMOS transistors have higher harmonics and more bandwidth; therefore, they are more sensitive to the low pass filter. Fo read more..

FM Transmitter for MP3 Player Powered from USB

Published on Wed, 15 Jul 2009 11:18:00

This's a simple VHF FM transmitter for MP3 Player that could be used to play audio files on a standard VHF FM radio. The transmitter circuit use no coils that have to be wound. This FM transmitter can be used to listen to your own music throughout your home. When this FM transmitter used in the car, there is no need for a separate input to the car stereo to play back the music files from your MP3 player. This FM transmitter use a chip made by Maxim Integrated Products, the MAX2606 [1]. This I read more..

Pre-emphasis for FM Transmitter

Published on Tue, 14 Jul 2009 16:14:00

This Pre-emphasis circuit was specially designed to be used with the FM Audio Transmitter. The circuit uses a dual opamp. The first opamp (IC1A) functions as a mixer and a buffer for the following correction network. The input sensitivity can be adjusted with the help of R3 (a lower value reduces the sensitivity). The 50 μs correction for the pre-emphasis is carried out by C5 and R6. IC1B buffers the signal before it is fed to the transmitter via K1. Since the FM transmitter is a mono ve read more..

FM Power Amplifier 88-108 MHz 600W BLF574

Published on Mon, 06 Jul 2009 04:27:00

BLF574, 50V, push-pull transistor using NXP’s High Voltage 6th generation of LDMOS technology was introduced recently and makes this FM amplifier possible with a single transistor. This eliminates the need for combiners and associated losses. The BLF574 is the latest high performance technology from NXP. These new 50 volt LDMOS transistors are ideal for that 1KW amplifier project. 600W BLF574 48V FM Pallet info. The two push-pull sections of the device are completely independent from ea read more..

Wireless FM Transmitter

Published on Mon, 20 Apr 2009 05:11:00

The following transmitter circuit works on 88-108 MHz frequency range. The most important part of this 88-108 transmitter is the Colpitts oscillator. C3,C4,C5,C6,CD1-CD2 ans L1 determine the transmission frequency. The RF Oscillator circuit has the BF982 MOSFET transistor wich is the active part. The others 2 transistors separate the VCO from antenna. Now we take a look at FM transmitter schematic. The first stage BF199 amplifies the weak signal from the vco and functions in constant load. read more..

FM Wireless Microphone Transmitter LMX4467

Published on Mon, 20 Apr 2009 04:58:00

This simple FM wireless microphone transmitter can transmit speech over a short range. It can be used as a simple cordless microphone. The circuit uses two integrated circuits from Maxim. IC1 a MAX4467, is an amplifier raising the microphone signal to a level suitable for frequency modulation (FM). IC2 is a voltage-controlled oscillator (VCO) with integrated varactor (a.k.a. varicap diode). Its nominal frequency of oscillation is set by inductor L1. The inductor value 390 nH provides an oscil read more..

Simple AM Transmitter with BC109

Published on Sun, 08 Feb 2009 18:45:00

Here's a simple Amplitude Modulation (AM) transmitter. This circuit is deliberately limited in power output but will provide amplitude modulation (AM) of voice over the medium wave band. The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator of this AM transmitter is built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to 1600KHz. These components can be used from an old MW radio, if available. Q1 needs regenerat read more..

13.8V 20A Linear Power Supply With 2N3055

Published on Tue, 03 Feb 2009 10:57:00

Linear power supplies for communication equipment are among the most commonly built electronic projects. Almost every technically inclined radio amateur has built at least one. But unfortunately most designs, even those published in well respected books, are unnecessarily complicated, or have some specific drawbacks. The design presented here is a little bit unusual in its arrangement, but offers some advantages over the usual designs that I will explain in the following paragraphs. A linea read more..

13.8V 20A Power Supply Using FET BUZ11-24

Published on Tue, 03 Feb 2009 10:31:00

This is a regulated DC power supply, short circuit safe, and with current limiter. It has been especially designed for current-hungry ham radio transceivers. It delivers safely around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. Let us see what we have got here. The power transformer should be capable to deliver at least 25A at 17.5 to 20V. The lower the voltage, the lower power dissipation. The rectified curre read more..

How To Design RF Filter Faster

Published on Mon, 02 Feb 2009 11:59:00

How to design RF Filter Fast? A Windows® electrical filter design and analysis program designed to expedite the design of lowpass and highpass filters using Standard Value Components (nearest-5% values). You can view your spectrum analysis filter design. SVCfilter™ is a program designed to expedite the design and analysis of lowpass (and highpass) filters with nearest 5% component values. Here are some pertinent features: SVCfilter is 32-bit Windows® electrical filter design softw read more..

Directional RF Power Meter

Published on Sun, 04 Jan 2009 15:59:00

Here's a powerful bench-top power meter that is based around two AD8307 log detectors which have a 90dB dynamic range for signal strength measurements. Tie that to a good directional coupler and you have yourself a very easy to build and calibrate power meter! Since the AD8307s respond very quickly to changes in signal level they are also perfect for deriving percent of modulation, peak power, average power and more. The real advantage to this power meter is its ability to measure very sm read more..

FM RF Amplifier 88-108 MHz 100mW-8W

Published on Mon, 29 Dec 2008 00:10:00

Here's FM RF amplifier 100mW-8W for 88-108 MHz. This amplifier circuit using the transistor BFR96 and 2SC1971 and equipped with a low pass filter Click link for more: Schematic Photo View Parts List Silkscreen Copper bottom Component layout read more..

Where Go for Test Equipment Rental

Published on Sat, 22 Nov 2008 01:24:00

Here is the best place to rent equipment when you do not want to buy it. At TestEquity, they not only strive to provide the best in new and used test equipment, but also the widest variety of purchasing options available. Whether your needs include buying, renting, or leasing equipment, TestEquity has a plan that will meet those needs. Below is a brief summary of our Test Equipment Rental and Leasing options. TestEquity is an Authorized Agilent Rental Company. TestEquity offers fast delivery read more..

Small AM Transmitter

Published on Thu, 20 Nov 2008 18:14:00

Here's a small AM Transmitter you may needed. It/s built into a plastic project box, and uses a piece of perfboard rather than a printed circuit board. Of course, a PCB would have been much more elegant, but designing and making one would have increased construction time by at least five times! The RF transformer of the transmitter is actually a 455kHz IF transformer taken from a junked transistor radio from the 1970s. I removed its internal 470pF capacitor. With the external 100pF capacito read more..

4 Channel Video Mixer Edirol LVS-400

Published on Sun, 16 Nov 2008 12:06:00

Here's a video mixer LVS-400 from Edirol , It  compact, simply-operated 4 channel video switcher is so easy to use, that even without any previous video experience, you can create very professional video transition and key effects for a professional video performance. LVS-400 is ideally suited for installations and It  offers both BNC and S-Video inputs and outputs. It includes 17 back-lit buttons for easy control in low-light environments, a T-Bar for manual transitions, a time con read more..

Circular Dipole Broadcast Antenna 88-108 MHz

Published on Sat, 15 Nov 2008 20:34:00

Here's a Circular Dipole Antenna construction for FM broadcast 88-108 MHz. This antenna is made of copper pipes with a diameter of 15 mm. This is a dual antenna type circular polarization Vertical / Horizontal, one of its features is the main penetration, that is to cover urban areas. This Circular Dipole Antenna designed by EA3ABN. See the diagram below for antenna dimension and download documentation for its construction DETAILS OF CONSTRUCTION   You can design a circular dipole a read more..

Directional Coupler with RF Filter for 88-108 MHz

Published on Tue, 28 Oct 2008 22:52:00

Here's Directional Coupler equipped RF filter with bandwidth is wide enough to pass any VHF 87.5 to 108 Mhz, cutoff frequency of 115 MHz being something similar. The harmonic 2 is located at 65 dB and harmonic 3 at 70 dB, to ensure optimum purity of the carrier. The low-pass filter is made in cells L / C type Butterworth, mounting parallel to 9 poles. Impedance input and output is 50 ohms. The low-pass filter is followed by the party meter reflectometer composed of a main line and two a read more..

20 dB/150 Watt RF Attenuator

Published on Fri, 17 Oct 2008 20:44:00

Here is an attenuator schematic for your spectrum analyzer. It's simple, easy and cheap way to make fairly high power RF attenuators. These are useful for directly connecting the output of a high power RF amplifier into a spectrum analyzer, frequency counter or other piece of test equipment (additional attenuation maybe required). This attenuator circuit  is based around a Bird Component Products attenuator chip, which are available from Radio Dan for $30 a piece. When properly hea read more..