MEF-107-2K+ Multi-Band End Fed Half Wave Antenna Transformer
Now you can make your dream low band antenna with just 259feet of wire (~79m) and operate on five bands without use of tuner at legal power using as much as 2kW+ ICAS.
Features massive ferrite core weighing 1.25 pounds (0.57kg) and very low Insertion loss
This is an End-Fed Half-Wave antenna (EFHW) transformer covering 160/80/60/40/30m amateur bands or any frequency in between. It transforms high impedance ~3000 Ohms at the end of half wave radiator to 50 Ohms and features very low insertion loss.
- NO TUNER needed!
- NO counterpoise needed! (Grounding recommended)
- Just adding a wire radiator of ~256 feet makes this antenna resonant on 160/80/60/40m.
- The wire of ~133 feet will give you low VSWR on 80 and 40m.
- Frequency coverage: 1-7MHz
- Power Handling: 2kW+ I.C.A.S
- Weight: 2 lbs. (0.95kg)
- Hardware: Stainless Steel
- Connector: Silver/Teflon SO-239
Just add 1/2 half wave wire to this transformer and tune the length to your preference. Note that antenna will be working on multiple frequencies. Half wave for 160m (~256 feet) will be two half waves on 80m and four (4) half wave on 40m band. If you desire to use it on 30m or new 60m band only, just cut the half wavelength wire for that frequency or any frequency from 1-10MHz. Wire length can be calculated by following formulas:
- Length (feet)= 468/Frequency (MHz) or
- Length (meters)=142.5/Frequency (MHz)
Always cut a wire a bit longer to allow for tuning to your desired frequency. Tuning depends on height above ground and nearby objects. There are so many ways to install the wire and your imagination is only limit. You can do it horizontal, vertical, sloping, in inverted “L” shape, Horizontal “L”, in “inverted “V” shape etc.
Such antenna will not need radials and in most cases NO Tuner at all. You can use it as vertical against good radial counterpoise too. Be a HAM and do some experiment.
Grounding at the lug next to the SO239 connector is recommended! Long wires tend to collect electrostatic charge (usually when the weather is stormy) which can produce ESD (electrostatic discharge) at the end of your cable and damage your equipment.
Insertion Loss measurements of MEF-107-2K+ transformer