ferrite ring

ferrite ring

Antennas : Baluns

• QRP Balun: A DIY Project - DIY project of a QRP Balun. Using a high permeability ferrite rod and an old B&W dipole center insulator, he constructs a choke type balun for QRP use. The balun aims to create as much inductance as possible at HF, offering a high impedance to common mode currents
  [ Hits: 59 | Votes: 0 | Rating: 0 ]
• Baluns and Ferrites Basics - Unlock the secrets of RF signal optimization in a presentation covering Balun essentials, diverse types, SWR Analyzer checks, revealing results, Ferrite impedance measurements, and practical applications on feeders and house conductors.
  [ Hits: 198 | Votes: 3 | Rating: 9.67 ]

• 4:1 QRO Balun - A home made 4:1 Ferrite QRO Bal-un with a FB 241-61 Type K
  [ Hits: 813 | Votes: 5 | Rating: 6 ]

• Beverage Transformers for HF Receiving Antennas - This FAQ covers building and buying transformers for loop-on-ground and Beverage antennas. Building one uses ferrite cores and thin wire. Buying is an option, with the DX Engineering BFS-1 being recommended. These transformers isolate the antenna from the cable to prevent unwanted signal pickup.
  [ Hits: 20 | Votes: 0 | Rating: 0 ]

• Chokes and Isolation Transformers for Receiving Antennas - Chokes and isolation transformers are essential for receiving antennas to mitigate common mode current, which induces noise and interferes with signal quality. Common mode chokes, formed by winding feedline through ferrite cores, block unwanted current effectively. Proper selection of core material and winding turns ensures resonance near the operating frequency, reducing interference. Isolation transformers further minimize interference, crucial for multi-transmitter stations.
  [ Hits: 59 | Votes: 1 | Rating: 9 ]

• Pro Audio Engineering - High-quality products for broadcast and amateur radio. Kx33 Low-RFI AC Power Supply for HF Transceivers, Elecraft Heatsinks, Fair-Rite Mix 31 Ferrites
  [ Hits: 119 | Votes: 0 | Rating: 0 ]

• Coil32 - Coil32 is a free coil inductance calculator, that allows to calculate: single layer and multi layer air core coils, toroidal air core coils, inductors on ferrite rings, in pot core, flat coils on the PCB, and also LC resonance parameters. The program have additional plugins to calculate another kinds of coils. The application is free for usage and distributing.
  [ Hits: 1571 | Votes: 6 | Rating: 7 ]
• 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: 396 | Votes: 1 | Rating: 1 ]

• Measured Data For HF Ferrite Chokes - FT-240 toroids measurements. The data was measured using well-calibrated HP instrumentation. All plots have been adjusted to a frequency range of 1-100 MHz on the horizontal axis and a resistance/impedance range of 10-1,000 ohms on the vertical axis. This adjustment facilitates comparison among different materials and aids in determining their suitability for use on the HF ham bands.
  [ Hits: 38 | Votes: 0 | Rating: 0 ]

• Behringer HA400 Headphone Amplifier and RFI - Removing disturbing RFI from the Behringer HA400 Headphone Amplifier, using ferrites and capacitors soldered in the main circuit board of the small amplifier.
  [ Hits: 121 | Votes: 2 | Rating: 5.5 ]
• Prevention and Suppression of RF Interference to Audio Systems - In this study, the author builds upon Muncy's research, demonstrating that radio-frequency current on cable shields affects audio systems through the "pin 1 problem" and shield-current-induced noise (SCIN). An enhanced equivalent circuit for ferrite chokes is proposed, addressing dimensional resonance and inductor self-resonance. Field tests confirm that chokes reduce interference across 500 kHz to 1,000 MHz. Guidelines for diagnosing and mitigating EMI from various sources are provided for product development and field installations.
  [ Hits: 47 | Votes: 0 | Rating: 0 ]

• DIY EMC/RFI Mains Filter for a Clean Shack - Utilizing snap-on ferrite cores and practical insights, the author enhances their shack's cleanliness against electromagnetic interference. With meticulous experimentation and installation, they improve noise levels across HF bands, reflecting on the effectiveness of their filter in minimizing common-mode disturbances. Updates underscore ongoing refinement and cautionary advice for optimal filtering and radio reception amid changing RF environments.
  [ Hits: 153 | Votes: 1 | Rating: 10 ]