One of the most popular antennas today is the end fed long wire antenna due to it ease of installation, portability and stealth in various installations. It can be a condo dweller’s only access to the world of ham radio or the best alternative for a backpacking SOTA (Summits on the Air) mountaintop expedition.
The antenna is simple to deploy, folds up easily for transport, and weighs under a pound, yet, with the proper length of wire, can work the 80-10 meter bands easily with the built in antenna tuner of most current day transceivers. You will need several components for a successful deployment of the end fed antenna and these are shown in the diagram below:
The antenna impedance matching components (BOX “Z” above) to match the antenna impedance to the coax line impedance (usually 50 ohms). For non-resonant end fed antennas, the typical feed point impedance is 300 to 600 ohms and a 9:1 impedance transformer (e.g. 450 ohm average antenna impedance to 50 ohm coax, also know as a 9:1 unun). For do-it-yourself antenna builders, 9:1 impedance transformer information is HERE
With end fed antennas, the coax is meant to radiate as part of the antenna system (serving as the “ground” or counterpoise) and therefore you need to use a Feed line Choke (BOX “FC” above) to suppress the common mode current on the outside of the coax feed line so it does not enter the radio and cause garbled communication.. The Feed line (FC) acts as a stop sign for RF current flowing back on the outside of the coax. The higher the choking resistance of the feed line choke, the less the coax braid RFI common mode current, and the less noise enters the radio. Feed Line choke alternatives are HERE.
The radio station is also a key component of the antenna system and has two functions: transmit and receive. Matching the transmitter to the coax feed line is often done with an antenna tuner and receiver systems should be installed to maximize signal to noise ratio. Reducing receiver noise is critical for weak signal reception and the use of coax noise filters AND receiver power supply lines (AC or DC) noise filters is usually needed for optimum reception. Reducing RFI generated by the radio station (you are the SOURCE of RFI) or received by your radio station (you are the VICTIM of RFI) is an important aspect of radio station operations. Palomar Engineers has many solutions for RFI problems – Click HERE to develop alternative strategies depending on your particular situation.
Want to compare End Fed Antennas? See: End Fed Antenna Secrets (PDF)
The “Bullet” End Fed Long Wire Antenna
The key to end fed antenna success is the matching network interface between the long wire antenna and the coax feed line and feed line choke at the transceiver. Palomar Engineers employs a dual core matching system that offers wide bandwidth (1-61 MHz), 500 watt PEP rating, and a connection for a counterpoise or ground if desired.
The antenna can be used as a sloper, “L” with a vertical section and a longer horizontal section, or as a random horizontal antenna between two trees or supports.
Our network 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. The Bullet uses all stainless steel connectors and a dual core ferrite 9:1 unun for higher power rating then many competitive products.
We sell the Bullet components separately so you can add you own wire type and length or you can purchase a complete antenna system including wire and end insulator.
Off Center Fed Dipole Antenna, 80-6 Meters (8 bands-including 15 meters), 500/1.5KW/5KW PEP rated - FREE shipping in USA
Excellent features:
*** Covers 80-40-20-17-15-12-10-6 meter ham bands
*** SWR < 2:1 on most bands, may require antenna tuner 80, 40 for full band use
*** 500 watts/1.5KW/5KW PEP (SSB-ICAS) options
*** Stainless Steel hardware for long life
*** Halyard Hoist for ease of installation
*** Insulated #14 wire for durability
*** High Strength insulators (may be black, white or gray)
*** 4:1 Balun and 1:1 Choke included in a single enclosure
Super convenient and quick – great for contest operation! Choose 500, 1500 or 5000 watt PEP (use 5KW model for digital modes over 1000 watts).
Unlike Buckmaster OCF antennas (at twice the price, and no WARC bands, 6 meter or 15 Meter operation, you can transmit and receive on 12,15 and 17 meters with our OCF - Better engineering and lower price - only from Palomar Engineers!
INSTALLATION
For best results support center at 30+ feet and ends over 15 feet. Angle of feed each side must be great than 45 degrees or 120 – 180 degrees total between each side preferred. Any length of 50 ohm feed line ok but longer feed lines over 50 feet may show reduced SWR on some bands due to losses in feed line and soil conductivity, nearby objects, etc. Due to local ground conditions, antenna height and feed line length, SWR may vary from samples shown and an antenna tuner may be required or some bands to bring SWR at end of feed line to acceptable levels. Overall length is 95+40 =135 feet.
FREE Shipping on orders over $100
Insulators may be black, grey or white depending on stock at hand when order is placed. Wire is stranded, insulated and black color.
5KW antennas are made to order and take approximately 10 days after order to ship.
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.
Note if you like the band coverage of this antenna but don't quite have 135 feet available, then consider the BULLET-8006 with very similar band coverage but only needs 95 feet of wire that is end fed.
Testimonial:
Chris Miller – Facebook 2/20/22
A tale of two very different antennas, and two very different companies... I started with the MyAntennas 75-10 strung across the top of a 15 foot hedge around my property, based on the company's claim on their website "Due to the High Impedance feed point, the antenna is less height-dependent. You can put it up at 10 or 50 feet in the air without much change in VSWR values."... Being new to the hobby and not getting the advertised SWR in this configuration, I reached out for help on the company's Facebook group... The owner berated me for not understanding how antennas work. I simply reminded him of the company's claim on their site. He would not reply to my emails, and kicked me out of the group... Fortunately there were a number of much more friendly and helpful people in that group that helped me to understand that height really does matter, despite the company's claim... So I used my drone to get the wire to the top of a tall palm tree on my property, and get very respectable performance out of the antenna... But being new, excited and curious, striving for knowledge and experience in the hobby, I wanted to see how the EFHW would compare to a similarly placed OCF... Palomar Engineers has multiple models that peaked my interest, so I reached out to the company to find out which model/configuration would work best. The owner of the company, Bob (AK6R) personally called me, asked questions about my location and my station, talked me through options, and explained to me the history and development of his "80-10 vertical radiator" model. This was the antenna he suggested based on the spacing and arrangement of palm trees at the QTH. Bob's willingness to share his knowledge and assistance was true to the spirit I have come to enjoy in this hobby... So over the weekend I contracted a tree service company to deploy the Palomar OCF just below the EFHW (You can see the ends of the two wires in the first photo, the EFHW terminating 5 or 6 feet above the OCF)... Performance is very similar where it counts as you can see from the SWR chart.... what's remarkable about the OCF is my noise floor drops 1 to 2 S units, which is huge for me, living in an urban environment where noise is obviously an issue... And of course the relatively flat SWR across the board, not just on points of resonance. I hope someone may find my experience between the two antenna types, or the two antenna companies, helpful. 73 KI6GEA
the ocf i purchased is the best working antenna i have ever had wa6nrg john NI5I: I was using a Buckmaster OCF, was given your 500 watt version second hand, then bought your 1500 watt version from HRO last summer. I wanted another. I love this antenna!
Typical installations are shown below:
Bullet End Fed Antenna Notes (PDF)
CAUTION
USE CAUTION WHEN INSTALLING ANTENNA AND KEEP AWAY FROM ANY POWER LINE WIRES!