Wall Wart RFI Noise Filter

Bullet Hybrid (4:1) HF Balun + 1:1 Choke, 1.8-61 MHz, 500/1500 Watts, OCF, Loop, Folded Dipole Antennas

BULLET-4-1-500EB
$119.95
In stock
1
Product Details
Country/Region of Manufacture: USA
Type: NEW
Input ohms/Output ohms: 50 in, 200 out
Frequency Range < 2:1 SWR (MHz): 1.8-100
PEP Power Rating (watts): 500
Transformer Topology: Braodband Ferrite
Hardware Type: Stainless Steel
Weight (pounds): 2
Antenna Compatability: OCF, Folded Dipole, Loop

The Bullet-4-1-500EB (500 watts PEP) or the SBULLET-4-1-1500EB (1500 watts PEP) are both multi-core, 4:1 (50 ohm to 200 ohm) balun plus a 1:1 feed line choke in a single compact (looks like a bullet) enclosure that is lightweight and easy to transport for your fixed/portable.Common Mode Rejection Ratio (CMRR) up to -30 dB for internal feed line chokes.

Very useful for multi-band Off Center Fed, folded dipole and multi-band loop antenna systems. Halyard hoist at top of balun for convenient attachment point. Input is via SO-239 UHF coax connector and output with side eye bolt output.

Dimension of 1500 watt model is 8.5 inches tall, 6.5 inches wide tip to tip on the eyebolts.

Shipping weights are 2 pounds for 500 watt version and 3 pounds for 1500 watt version.



Remember we over engineer our products, to out perform our competition - just compare the weight and frequency range of our baluns to theirs and you will know we put much more into our products so you don't have to worry about failure at a critical moment.


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Wall Wart switching DC power supplies that plug into the AC power line plug and provide DC power to laptops, routers, battery chargers, cell phone chargers, etc are a known source of broadband RFI (a.k.a dirty electricity) that effects many electrical devices including computers, radio receivers, HDTV systems, etc.  In many cases this extra RFI noise effects computer I/O speeds since they have to error correct the information packets many more times due to the noise interference causing packet errors.  A ferrite ring can often increase data throughput by reducing the error correction to normal rates.

A simple ferrite ring filter on the DC power line can help suppress the RFI noise affecting the victim device or keep the DC power cord from acting as an antenna and radiating RFI into other victim devices. This kit is also useful on laptop computer supplies, routers, cable modems, wireless phone charges, etc.

RFI WW Installation 300x288 - Wall Wart RFI Noise Filter

Installation is quick and easy: Just wrap the DC power cord through the center of the ring filter as many times as you can and reinstall.  For best results with long DC power lines, use one at the ring filter at the wall wart end (to prevent the wall wart power supply from using the DC line as an antenna) and another at the DC plug end (to prevent the electronics in the powered device from using the DC power cord as an antenna).  Typical installation is shown below:

The filter suppresses RFI in from .1-100 MHz.   Inside diameter is 3/4 inch/19 mm.

Since most households and office environments have multiple wall warts we offer the Wall Wart RFI Filter kit in bulk quantity packages.

Known RFI Generators include Roku/Sling-TV power adapter - Interference heard in the AM broadcast band
 and harmonics.
Also many ethernet Cable/DSL modems, cell phone chargers, computer power adapters have the same issue:
using the AC or DC side of the power supply as a radiating antenna.

RFI solution is to use a linear power supply, change adapters or wall wart ferrite filters