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Bidirectional 2.4 GHz One Watt Amplifier - This will show you how to add a bi-directional, 2.4 GHz amplifier to your Proxim Symphony for under $100. Bi-directional means you can mount the amplifier at the antenna to help overcome any cable loss, and the amplifier will automatically switch between receive and transmit modes. The cost is reduced by using readily available materials and components. __ Green Bay Professional Packet Radio
Bidirectional 900MHz One Watt Amplifier - This device is a stereo amplifier for a high sensitivity stereo parabolic microphone. It can be used for listening to distant sounds. Typical parabolic microphones are monophonic, this unit has a stereo audio path that helps produce more realistic sounding audio. The Big-E can be used with headphones or as an audio source for a stereo tape recorder __ Green Bay Professional Packet Radio
Bipolar transistor mixer - Ham RadioV-U)HF AMPLIFIERSchematic __ Designed by Guy Roels ON6MU
Bipolar Transistor Tester - This tester is primarily meant to test bipolar transistors. It can indicate the type of the transistor as well as identify its base, collector and emitter pins. The circuit is very__ Electronics Projects for You
Bootstrapping a Phase Locked Loop for Better Performance - This paper describes a bootstrapping technique for phase locked loops to improve the oscillators’ performance 1 . The compensation scheme may be useful for correcting aging, warm-up characteristics, temperature stability, short-term stability, and vibration induced phase noise. __ Designed by Charles Wenzel
Broadband UHF Amplifier - This design uses an GALI-39+ (from Minicircuits) as it has the lowest noise figure (of this series) NF = 2.4 dB. The gain is 20 dB. The bias current can be adjusted by choosing six resistors. The bias of the monolithic amplifier is done with an TCBT-14+ (Minicircuits), as it is very challenging to do it better __ Designed by Alexander C. Frank, aka Ajarn Changpuak
Broadcast-Band RF Amplifier - The complete schematic is shown in Fig.1. The circuit has frequency response ranging from 100Hz to 3MHz; gain is about 30dB. Field Effect Transistor Q1 is configured in the common-source self-biased mode; optional resistor R1 allows you to set the input impedance to any desired value. Commonly, it will be 50 ohms __ Designed by Tony van Roon VA3AVR
Bug Detector - Figure 1 shows a schematic diagram of the Countersurveillance Monitor. The circuit, built around a single integrated circuit (U1. an MC3403P quad op-amp), three transistors (Q1-Q3), and a few support components, receives its input from the antenna (ANT1). That signal is fed through a high-pass filter, formed by C1, C2, and R1, which eliminates bothersome 60-Hz pickup from any nearby power lines or line cords located in and around buildings and home. __ Designed by Vincent Vollono and Tony van Roon
Bug Detector (mini) - This project is a handy piece of TEST EQUIPMENT. You can never have enough assistance when designing FM bugs. The first thing you need to know after putting a bug together is the fact it is transmitting.
This project gives you this indication. Once you know a bug is transmitting, you can work on getting the best output power and adjusting the frequency to a blank spot on the dial. __ Designed by Collin Mitchell
Bug Detector with Beep - This circuit is not open for discussion. Although working perfectly, it was experimental. I will answer no emails in regards to this circuit. If you are looking for a more serious and reliable bug detector, . __ Designed by Tony van Roon VA3AVR
Build a Band Pass-Band Reject Two Meter Duplexer - From the W1GAN article in the July 1972 QST
Build a good Audio Buffer Amplifier - Audio power amplifier circuit diagrams / circuit schematics __ Designed by Kevin Custer W3KKC
Build a good GaAs FET preamp for 2 meters, 222MHz or 440MHz - This circuit will work on 2 meters, 220 or 440 Mc. Some part values are different for the 3 bands, however general layout and construction are similar. __ Designed by © Kevin K. Custer W3KKC
Build a Rugged Half-Wave Coaxial Antenna - This is a coaxial sleeve dipole antenna and is the same basic design as the California Highway Patrol uses at some base stations (others use full dipoles, ot even a pair of them). __ Designed by Courtesy of the Scanner Buff Network
Build a Two Channel Signal to Noise Voter - As hand-held transceivers (H-Ts) become smaller, and low power, battery conserving operation becomes more popular, the disparity between the transmitting range of a typical 100 watt repeater compared to the repeater accessing range of a typical 1 watt or less H-T becomes more and more apparent. How often have you found it difficult (or impossible) to access a repeater with a low power H-T even though you can hear the repeater at full quieting? This can happen even if the repeater is equipped with a high sensitivity, state-of-the-art receiver. __ Designed by Mark Kolber WB2WHC
Build your own Iso-Tee - Build an Iso-Tee from an ordinary T-adapter. __ Designed by Ted Bleiman K9MDM
Build Youself a Service Monitor? - A simple deviation monitor circuit used with a scanner receiver. __ Designed by Tom Alldread VA7TA
Build Youself a Service Monitor? - For creating a COS signal on radios that don't have one. This is a VOX circuit that uses a FET as the input amplifier to avoid loading down the source. __ Designed by Tom Alldread VA7TA
Building a simple crystal radio - A crystal radio is the distilled essence of a radio. It has very few parts, it needs no batteries or other power source, and it can be built in a short time out of things you can find around the house. __ Designed by Simon Quellen Field
Building blocks - Radio building blocks __ Designed by EI9GQ homebrew radio |
