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Universal USB digimode interface supports CAT (Yaesu), CI/V (Icom) & RS-232 (Kenwood) units - Microcontroller based electronic circuit __ Designed by Aleksander Stare
USB / CAT (CI-V) adapter tested with FT-8900, FTB-9800, VX-7R, VX-7, FT-817 & IC-706MkIIG - Schematic only, no circuit description included. __ Designed by Aleksander Stare
Use an Astron power supply remotely? - Don't run to the repeater site to reset the Astron anymore! (scroll down to the Reset Circuits) __ Contact: Mike Morris WA6ILQ
Using Part 15 Wireless Ethernet Devices for AM ateur Radio - Hints, tips and rules for using off-the-shelf hardware for amateur radio Part 97 operations. __ Amateur Radio circuits from Green Bay Professional Packet Radio
Using the MC145158 PLL Frequency Synthesizer - Simple overview and source code for the Motorola MC145158. __ Amateur Radio circuits from Green Bay Professional Packet Radio
Variable Bandwidth CW Filter - As the sunspots return and DX propagation conditions to improve, the age old problem with QRM begins to show up on the amateur bands. Fortunately, help is at hand. The circuit in figure 1 is a variable bandwidth CW filter using two IC's. The first IC is a 741 op amp used as an active filter and the second IC is a 386 audio amp IC. This circuit connects to the headphone or speaker jack of your HF rig __ Designed by Radio Amateur Society of Norwich
Versatile end-fed wire - A piece of wire of almost any length can be used as an antenna on the HF bands. However, just because an antenna can be made to work is no guarantee that it will perform efficiently. This article will initially concentrate on the half wavelength of wire and its useamateur radio construction projects. __ Designed by Peter Parker VK3YE
Very High Gain Crystal Earphone Amplifier - This simple, one-transistor amplifier provides a voltage gain over 1000 (60 dB) for driving a high impedance ceramic (crystal) earphone. The high gain is achieved by replacing the traditional collector resistor. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Very Simple Circuit ADSB Receiver using a TV tunder to alLow reception of aircraft transponders - With this design you can expect to get several 100 km range with a good antenna. I use a home made J-pole with a single 32 Eurocent BFP420 transistor giving excellent low noise gain for very little money. It can be bought like most of the needed components at Reichelt. Many good quality (Kathrein for example) Satellite L band line amplifiers use this transistor and if you can get at least 12 Volts to the preamp they offer excellent performance despite being laid out for 75 Ohms. I'll document the preamp later. This is what you can get in Luxembourg with a clear view to the South for several kilometers __ Designed by Edward John Cardew
VFO from 2001 ARRL Handbook
4.20 - Schematic only __ Designed by Jim Osburn, WD9EYB
VFO from 2001 ARRL Handbook
7.74 - Schematic only __ Designed by Jim Osburn, WD9EYB
VHF 6 Meterband RF Amplifier - Ham RadioAF AmplifiersSchematic __ Designed by Guy Roels ON6MU
VHF Receiver Converterer - For Q1 and Q2 I used a pair of 3SK45 dual gate FET's. Most VHF N-Channel dual gate MOSFETs should work fine. I have used 3SK88, BF961, and BF981 FET's in this circuit. If you decide to use a GaAsFET for Q1, you will probably need to use a Zener diode to reduce the drain voltage to a safe level. L1 is 5 turns of 1mm copper wire, tapped at 1 turn,coil diameter 7mm, L2 and L3 are 5 turns each. T1 primary is 9 turns on a Toko 10mm former (old IF transformer) T1 secondary is 2 turns. The screening can and outer ferrite cup are not used. __ Designed by EI9GQ homebrew radio
VHF Receiver for Weather Satellites - Build this compact 2-channel VHF FM receiver and pull in your own weather satellite pictures.__ SiliconChip
VHF Synthesizer - This synthesizer was designed to drive a low cost VHF Aircraft Band receiver, but it has applications to any VHF radio in the 75 to 180 MHz band. Low phase noise and reference feed through were also design goals. The design was implemented in just a few day's and was fully tested and characterized. Code was written to allow the synthesizer to be turned on and programmed, thus eliminating extra firmware support from the client. __ Designed by Steve Hageman
VLF Upconverter for Shortwave Receiver - The schematic above is a simple up converter which I used in conjunction with a short-wave receiver to quite successfully to monitor solar flare activity a few years ago. You can use a 3.5 or 4 MHz crystal for Y1 to up convert from about 10 KHz to 150 KHz to either 3.510 or 4.010 MHz respectively. A long wire antenna was used here but a VLF loop antenna __ Designed by Radio-Sky Publishing
Wee Willy 75 Meter DSB Transceiver Project - Many amateur experimenters stay in the familiar comfort zone of HF. A small number venture into VHF, and even fewer devote time designing, building and operating for the UHF & microwave spectrums.
Wideband SWR meter - A very simple design, cheap to built, does not require adjustment and works well! Depending on specific components and construction technique used, the upper frequency limit will be somewhere between 150MHz and 5GHz! __ Designed by Manfred Mornhinweg
Wideband VHF/UHF/SHF 22dB RF preamp with MAR-6 or MAR-8 (MSA-0885) - The MAR6 (MSA-0686, 0685, 0885) is a high performance silicon bipolar Monolithic Microwave Integrated Circuit (MMIC) housed in a low cost, surface mount plastic package.
This MMIC is designed for use as a general purpose 50 W gain block. Applications include narrow and broad band IF and RF amplifiers in commercial and industrial applications. __ Designed by Guy Roels ON6MU
Wireless Network How-To - Extremely detailed account of a Part 97 point-to-point 2.4 GHz wireless link. __ Amateur Radio circuits from Green Bay Professional Packet Radio
Xtal Radio Plans - The radio in diagram 1 uses a variable inductor (coil) for tuning. The radio in diagram 2 uses a variable capacitor for tuning. Both radios are otherwise the same. The coil consists of 110 turns of 28 gauge enameled magnet wire wound on a 1.5" form. (toilet paper tube is easiest to get, but you can use something like plastic or other non-conductive material- hollow is best. D1 is a common 1N34 germanium diode- this is the detector. The crystal earplug is not the same thing as one would commonly find at your electronics parts store __ Designed by Keith Addison
Zinc RF Amplifier - Zinc negative resistance RF amplifier for crystal sets and negative resistance regenerative receivers. __ Designed by Nyle Steiner K7NS |
