rf choke

rf choke

Pages: [prev] 1 2

• 40m loaded dipole - This is an short dipole for 7 MHz. Total length of this dipole is just 10 meters, 33 feet. Missing lenght is balanced by a coil made of 49 turns of a 40mm diameter pvc pipe. The use of a choke balun is recommended, as always, to adapt the unbalanced coax cable to the balanced antenna, and to prevent RF feed back along the coax shield.
  [ Hits: 194 | Votes: 4 | Rating: 8.75 ]

• Choking balun for 160-30 meter band - Choking balun for lower HF and MF bands. (1.8MHz - 10MHz). Requiring a choking balun to isolate the potential RF pick up on the coax cable as it runs past equipment such as computer within the radio room at lower HF and MF frequencies a simple method of winding RG58 coax onto a Powdered Iron Toroid Core was constructed.
  [ Hits: 196 | Votes: 3 | Rating: 6 ]

• How to evaluate Choke performance - If you want to build your own common mode choke, this article explains how to measure the efficiecy of your choke before using it. In the examples has been used Amidon FT240-31 toroids.
  [ Hits: 210 | Votes: 1 | Rating: 8 ]
• High Performance common-mode chokes - May 2015 Radcom Article on common-mode chokes that can be used for control cables, phone lines, but mostly on typical HF antenna systems. This article explain what common mode chokes does, why you meay need one, properties common mode chokes should have, how to build and measure performances.
  [ Hits: 687 | Votes: 1 | Rating: 10 ]
• Patented RF choke test - A reproduction test of a a binocular ferrite core and winds a total of 7 turns is a patented rf choke with an unusual winding, although this winding scheme reduces the inductance, it might result in a much larger bandwidth over which the choke has a sufficiently large impedance. The Author test this model by reproducing the choke.
  [ Hits: 105 | Votes: 0 | Rating: 0 ]
• High Performance Common-Mode Chokes - This article is an attempt to shed some light on this misunderstood component, covering topics like why you need a common mode coke, what it does, what properties it should have, ho to build one and how to measure its performance.
  [ Hits: 132 | Votes: 0 | Rating: 0 ]
• A High Performance RF Choke for the HF bands - Home brewing a high performance, high power common mode choke for HF bands
  [ Hits: 152 | Votes: 0 | Rating: 0 ]
• RF Choke with Bifilar Windings - This article presents an RF Choke featuring an 11-bifilar turn winding of #14 house wire on a Fair-rite FT240-31 toroid. The choke is enclosed in a 3D-printed case from Thingiverse, though this may pose thermal concerns at higher power levels. With SWR concerns up to 30MHz, the author plans to employ two series chokes at the rig input for improved performance. This choke offers versatility for portable use, with potential mismatch resolution using an antenna tuner. Further testing is anticipated upon the arrival of new cables.
  [ Hits: 86 | Votes: 0 | Rating: 0 ]

• Space-Efficient Excellence: Inverted L Multi-Band HF Antenna - Discovering a solution for limited space, the inverted L HF antenna emerges as a stellar performer. Half the size of a dipole, it ensures optimal installation in restricted areas, maintaining superb transmission (TX) and reception (RX) characteristics. Spectrum Communications' multi-band version, featuring traps, proves even more space-friendly without compromising performance. A fiberglass pole offers sturdy support, while proper grounding, an RF choke, and occasional tuning contribute to a high-performing and reliable antenna system.
  [ Hits: 186 | 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 ]

• A600 Power Amplifier Project - This is a power amplifier project for a RF 600W 1.8 MHz to 70 MHz linear amplifier including a Low Pass Filter. Projects includes schematics, pictures, PCD design, fans details, note on PA ferrite chokes and assembling instructions
  [ Hits: 100 | Votes: 0 | Rating: 0 ]

• 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 ]

• Common-mode chokes Measurements - Common-mode chokes are useful solutions for RFI reduction. Winding a few turns of coaxial cable on the FT 240-31 toroid can reduced the noise below the received noise floor. In this article author measure different chokes
  [ Hits: 156 | Votes: 1 | Rating: 8 ]

Pages: [prev] 1 2