Antennas : 2M
- 2m Quad Turnstile Antenna
- The loops are made of 10 mm round aluminum tube. No bending pliers was used to gently bend 90 degrees to obtain a square with 53 cm inner sides.
Each loop has an impedance of approximately 100 Ohm. To connect both radiators in phase, a quarter wave long feeder of 100 Ohm is required.
[ Hits: 163 | Votes: 0 | Rating: 0 ]
- Six Meter Quad Turnstile Antenna
- Simple 6 Metre DX Antenna based on an article by LB Cebick in QST May 2002 on a Quad Turnstile antenna. This antenna is basically two full wave loops mounted at right angles fed 90 degrees out of phase to produce an omni-directional horizontally polarized pattern
[ Hits: 543 | Votes: 1 | Rating: 9 ]
- 6 Meter Quad Turnstile Antenna
- A quad turnstile consists of two cubical quad loops oriented in a diamond configuration and angled 90 degrees apart from one another with both diamonds sharing the same top and bottom points
[ Hits: 115 | Votes: 0 | Rating: 0 ]
- The Antenna Torque Calculator
- This unique online tool helps Ham Radio operators to choose the right rotator for medium and large HF antenna systems. The algorithm implemented in this calculator is the result of 40 years of experience in the HF Antenna sector. Given the Wind Speed, the total antenna square area, and the boom length, it will return the calculated torque value.
[ Hits: 83 | Votes: 0 | Rating: 0 ]
- Making a good balun
- The normal way to make a good balun is to wind a core with a bifilar winding about 8-10 turns, and then connect the coax to one side and the antenna to the other.
[ Hits: 431 | Votes: 0 | Rating: 0 ]
- DIY isolation transformers
- Article about isolation transformer construction to perform optimal impedance matching. Winding the FCP isolation transformer, includes interesting table for Winding Turns and Lengths and Core Configurations for T300 T200 T400 toroids
[ Hits: 225 | Votes: 0 | Rating: 0 ]
- End-Fed HalfWave Matching Unit for SOTA operations
- An end-fed half wave antenna matching unit made of 3:24 turns ratio on a FT140-43 toroid with a 150pF capacitor across the input.
[ Hits: 185 | Votes: 0 | Rating: 0 ]
- The End-Fed Half-Wave Antenna - Presentation
- A very well done presentation about End-Fed Half-Wave antennas. This PDF document contains a summary of experiences in how to build custom EFHW antennas. Includes an interesting comparison table of UnUn configurations with recommended toroids, Wire size, turns and capacitors. An useful recap on common errors in building homebrew EFHW Ununs completes the document.
[ Hits: 220 | Votes: 3 | Rating: 8.67 ]
- Magnetic Loop Antennas
- A complete guide to magnetic loop antenna construction, with analysis of multi-turn and single-turn magneti loops, and and insight on choosing the optimal capacitor, or homebrewing your own butterfly capacitor
[ Hits: 1120 | Votes: 1 | Rating: 10 ]
- DIY Dual Band 144-440 MHz vertical antenna
- A homemade VHF/UHF vertical antenna made essentially with RG58 coax cable, with a 9 turns choke balun to prevent the shield acting as a RF Radiator.
[ Hits: 594 | Votes: 4 | Rating: 3.75 ]
- High Altitude Ballooning, From The Ground Up (and back again)
- High Altitude Ballooning makes for a challenging project that sometimes turns into an engrossing hobby. Whilst it is not rocket science it does encompass a wide range of fields (sometimes literally) and there is a lot to learn before you send your first flight up into the sky.
[ Hits: 81 | Votes: 1 | Rating: 10 ]
- Icom IC-2720H One Page Operating Guide
- An operating guide for the com IC-2720H VHF/UHF Radio, includes Turning the power On or Off, Selecting the Output Power, Activating Memory Mode, Operating in Memory Mode
[ Hits: 152 | Votes: 0 | Rating: 0 ]
- mini Ring-Core-Calculator - Calculate windings on ferrite cores
- The program can be used to calculate inductors (coils) and their number of turns on ferrite cores, ferrite shells and air coils. These can be used for baluns, Ununs, bandpass filters, low pass filters, resonant circuits, and more. The technical specifications of the cores are already integrated in the program.
Application is free and runs on Windows 32 bit versions only. To make it run on Windows 10 64 bit need to be unzipped in a single folder.
[ Hits: 160 | Votes: 0 | Rating: 0 ]
- Online Helical Coil Calculator
- This online calculator will give as output the Inductance L of a coil, including the total lenght of the wire needed to wound the coil.
As input, requires the Diameter, number of turns, wire diameter and turn spacing
[ Hits: 120 | Votes: 3 | Rating: 5.33 ]
- Online Coil Inductance Calculator
- This online calculator will return the inductance of a coil. It will ask you the total number of turns, the total diameter of the coil and its lenght, from the first winding to the last.
Obtaining the correct inductance in winding a coil can be easy if you already know how many turns are needed.
Available in inched and centimeters,
[ Hits: 44 | Votes: 0 | Rating: 0 ]
- One-turn loop inductance Online Calculator
- The high-frequency inductance of single-turn loops of various shapes made of round wire can be estimated accurately with a simplified formula
[ Hits: 67 | Votes: 1 | Rating: 10 ]
- RV marine battery as power source
- Turning an RV marine battery into a massive 12-volt emergency power source
[ Hits: 158 | Votes: 2 | Rating: 9 ]
- How to convert Server Power Supplies
- The practice of converting computer server power supplies to make a very high quality high power supply at low cost is attractive. It doesn't normally require any modification to the supply but the hard part is figuring out how to trick them into turning on.
[ Hits: 714 | Votes: 0 | Rating: 0 ]
- How to make a MMDVM Digital Repeater
- The MMDVM is a device that interfaces PC to radios, can be used with a raspberry pi, turning a normal analog radios into a digital node connected to the internet or very simply as a digital repeater.
[ Hits: 150 | Votes: 0 | Rating: 0 ]
- Return Loss Bridge
- This Return Loss Bridge has been designed to characterize the input impedance of a receive strip, and the output impedance of a transmit strip
[ Hits: 238 | Votes: 0 | Rating: 0 ]