Wall Wart RFI Noise Filter

Bullet End Fed OCF Antenna System, 100-1500 Watt Options, 25 Feet, 20-6 meters+WARC, SOTA, POTA, VOTA

SKU BULLET-2006-100
$119.95
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List price $179.95 Save 33%
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Bullet End Fed OCF Antenna System, 100-1500 Watt Options, 25 Feet, 20-6 meters+WARC, SOTA, POTA, VOTA
Product Details
Brand: Palomar Enineers
MPN: BULLET-2006-100, -500, -1500
Frequency Band(s): 20-17-15-12-11-10-6 meters
Power (PEP watts):: 100/500/1500
Length (ft):: 25 feet

Palomar's Unique End Fed Off Center Fed Antenna

Need a high performance, multi-band, stealthy antenna system that is easy to setup and use? Get the Bullet antenna matcher with the antenna wire, insulator and feed line choke all in one convenient package (great for HOA restricted areas, camping and portable operations too.)

Why is this end fed OCF antenna a better choice than and End Fed Half Wave (EFHW)? More bands, shorter length and no dangerous high voltage at antenna feed point from VOLTAGE FED 49:1 TRANSFORMERS!!!

Off Center Fed (OCF) antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center. The Palomar Engineers 2006 OCF is a very popular antenna and consists of an off center fed dipole with wire dimensions of 25 feet and 7 feet and it will work all bands from 20-6 meters. The BULLET-2006 uses the same dimensions but the wire section is 25 feet as in the OCF and the coax outer braid is used for the “other” part of the OCF dipole. We place a choke on the coax at the 7 foot distance from the matching unit and we essentially have an OCF antenna with its great frequency range, but with only a 25 foot wire length instead of the 33 feet required by the regular OCF or 20 meter EFHW (and we get ALL the bands from 20-6 meters!). You feed the antenna from one end which may be more convenient for some installations. This antenna will work on 20-17-15-12-11-10 and 6 meters. Most bands are under 2:1 SWR and easily tuned by your transceiver’s internal antenna tuner or external tuner used with an amplifier.

This antenna is a great stealthy primary or backup antenna and works exceptionally well for apartments, condominiums, homeowner, mobile home parks, RV applications and ARES, RACES, MARS, EMCOMM, NVIS, First Responders and Emergency Preparedness. Compact, Stealthy and Light weight for back packing and portable use. Also works great with SOTA, POTA with a telescoping fiberglass pole support.

The antenna is simple to deploy, folds up easily for transport, and with the 25 foot included wire, can work the 20-6 meter bands easily with the built in antenna tuner of most current day transceivers. Some bands may not even require a tuner if the antenna length and counterpoise choke position is adjusted correctly. (see SWR graph in gallery).

These antennas are MUCH BETTER PERFORMERS than End Fed Half Wave antennas because they work the WARC bands, DO NOT HAVE A DANGEROUS HIGH VOLTAGE at the antenna connection and are shorter to fit in smaller spaces yet provide more band coverage up to 6 meters!

Make the right choice - use the BULLET-2006 and enjoy the expanded band coverage, additional safety and smaller footprint!

Part #'s:

BULLET-2006-100 for 100 watts SSB/FT8

BULLET-2006-500 for 500 watts SSB/FT8

BULLET-2006-1500 for 1500 watts SSB/1000 watts FT8

The antenna can be used as a up or down sloper, “L” with a vertical section (at either end) and a horizontal section, or as a horizontal antenna between two trees or supports.

BULLET Matching Unit

Our antenna matching network is called the “Bullet” because of it shape and its effectiveness at taking down or contacting distant (DX) stations all over the world under the right conditions.

For best results we recommend that the coax feed line be at least 25 feet. We also recommend a coax noise filter (part# CMNF-500-50 or CMNF-1500 for high power) near radio end of the coax feed line to reduce RFI common mode current from interfering with the radio operation.


Installation

For best results raise the Bullet matching unit as high as possible (use a tree or vertical support) and then extend the antenna wire horizontally or as an “L” (horizontal with vertical end drop). The antenna may also be deployed as a sloper with the Bullet matching unit at the top (best) with the wire sloping toward the ground (with the end high enough to avoid contact by humans or animals), or at the bottom of the sloper with the antenna wire rising to a higher point.

Any length of 50 ohm feed line ok (over 25 feet minimum recommended) but longer feed lines over 50 feet may show reduced SWR on some bands due to soil conductivity, nearby objects, etc. Due to local ground conditions, antenna height and feed line length, SWR may vary and an antenna tuner may be required or some bands to bring SWR at end of feed line to acceptable levels. Position a feed line choke (part# SOFLC) 7 feet from the matching unit and wrap 5-6 turns of RG-8X size coax thru the center. Note 3-4 turns of 1/2" OD coax will also work fine as a choke.

Use a good quality 50 ohm cable adequate for the power level of your station.The Bullet matching unit is rated for 500 or 1500 watts PEP (depending on model) for SSB and 50% for CW or digital modes. If the matching unit becomes warm to the touch after transmitting at high power, reduce the power output or the internal matching unit may become damaged.

NOTE: The matching unit output is DC grounded to bleed off static electricity, however it is not RF grounded.

Need more bands? Check out the BULLET-4006 for 40-6 meter operation.

Bullet-2006 Testimonial

I created this short antenna to be used by the SOTA, POTA and portable ops who need a small, stealthy antenna that is quick to deploy yet cover more bands than the limited frequencies of the EFHW antennas and is safer with no high voltages at the antenna feed point.

I put it up as a flat top (all horizontal for you newbies) at about 30 feet between two trees and used 100 feet of coax to the station with a coax choke at 7 feet from the matching unit.I used the 500 watt version (BULLET-2006-500) which only has 25 feet of wire and a 7 foot coax braid as the radiating elements.

I only spent 2-1/2 hours on the air using FT8 running 400-500 watts to test the power limits and called CQ on a late Friday afternoon on all the bands from 20-10.

Boy was I surprised! This antenna is a great performer! In that small amount of time I worked all around the world including prefixes from:

10M: KI5, PU4, 8I7, ZL1, ZL2, YB1

12M: VK3, JA7, VK1, CE1, PY5, VK4, JA8, 5W1

15M: AC9, PY5, JA8, KG7, JK1, HL2, N8

17M: CS8, JH5, KU5, F5, KC1, JE2, W5

20M: NC3, K4, KO4, AG5, N8

I had no problem running 400-500 watts FT8 almost continuously with the 500 watts rated matching unit and the well matched antenna. It will probably take more power on SSB but we like to be conservative in our ratings so you don’t have to worry about saturation or over heating like other manufacturers!

Your results may vary from mine in Southern California, but I was very impressed what a 25 foot piece of wire will do. FYI Wire was running north south direction.

Have fun – get on the air and take part in one of the best hobbies ever!

Bob, AK6R


NOTE: due to the nature of antenna systems and the modifications many users perform and the transmitter power levels that may be applied higher then the specifications, the antenna systems are NOT RETURNABLE unless they are unused, in the original packing with the original invoice and a return request is made withing 30 days of original purchase.

SWR TECH NOTE:The SWR graphs shown are specific to the conditions listed including antenna height, configuration (flat top, inverted V, inverted L, etc.) and direction, feed line length and type, geographic location and soil condition, calibration and accuracy of SWR instruments used. Your SWR measurements will probably be different and manufacturer takes no responsibility or liability for these differences beyond the purchase price of the antenna.


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