Description
MEF-107-2K-Plus Multi-Band End Fed Half Wave Antenna Transformer 75:1 Ratio
Now you can make your dream low band antenna with just 259 feet of wire (~79m) and operate on low bands without the use of a tuner at legal power using as much as 2kW ICAS.
Features massive three (3) stacked 3″ inch dia. ferrite core weighing 1.25 pounds (0.54kg) and very low Insertion loss <0.25dB
This is an End-Fed Half-Wave antenna (EFHW) transformer covering 160/80/60/40m amateur bands or any frequency in between. It transforms high impedance ~3750 Ohms at the end of the half-wave radiator to 50 Ohms and features very low insertion loss. Average insertion loss from 1.8-7.3MHz is less than 0.25dB
NOTE: for decent efficiency and match the minimum height for a horizontal portion of the antenna is 0.1 wavelength above ground (~50 feet or 15 meters for 160M band). Yes, it can work also at 30 feet above the ground but with less efficiency due to increased ground loss (absorption)
- NO TUNER needed!
- NO counterpoise needed! (Grounding recommended)
- Just adding a wire radiator of ~259 feet makes this antenna resonant on 160/80/60/(40)m.
- 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
- Polycarbonate housing
- Hardware: Stainless Steel
- Connector: Silver/PTFE (Teflon) SO-239
Insertion loss for MEF-107-2k+
Assembly
Just add 1/2 half-wave wire to this transformer and tune the length to your preference. Note that the antenna will be working on multiple frequencies. Half-wave for 160m (~259 feet) will be two half-waves on 80m and four (4) half-waves on the 40m bands. If you desire to use it on the new 60m band only, just cut the half-wavelength wire for that frequency or any frequency from 1-8MHz. The wire length can be calculated by the 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 the 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, an inverted “L” shape, Horizontal “L”, in “inverted “V” shape, etc.
Such an antenna will not need radials and in most cases NO Tuner at all. Be a HAM and do some experiments.
Grounding at the lug next to the SO239 connector is recommended! Long wires tend to collect electrostatic charges (usually when the weather is stormy) which can produce ESD (electrostatic discharge) at the end of your cable and damage your equipment.
Barry – N8DAD –
I just ordered this 160-40 -2K plus, what a great job, works great, i only have mine at 25ft high and its straight flat-top. i have mine at 246ft long to bring it up to 1.9mhz and works great on the bands it suppose to work on. always a great company
bud –
160-40 -2K plus, what a great job, works great, have mine at 40 ft. high to 90 ft. slope. I have mine at original length. 1.7mhz- 3.6 mhz-5.400mhz -7.225. out of the box and works great on the bands it suppose to work on. always a great company.
Joe – K5WVA –
Got a question? Just ask. You get quality support. Just bought my second EFHW from myantennas. Never a complaint.
Joe –
Incredible quality. No instructions. You need to download them. I used with the 160m wire kit. Tuned up perfectly. One call responses on 160, 80 and 40 meters. Performance always depends on your installation of course, but I ran the first 85 feet vertical then a long easy slope to 20 feet. Didn’t need to adjust wire length. Using just radio internal tuner. Used a crossbow to shoot the messenger line over a very high sycamore limb. Beautiful performance. Quality wire.
I can’t say enough.
albert21 –
Took delivery of my unit. Truly build like WW 2 Tiger Tank. Arrived beautifully packaged. First thing that struck me is the weight… do not drop this UN/UN on your foot, you will be limping for a week!
I got the 260 feet of wire with mine… looks strong enough to haul the Titanic of the ocean bottom. Will install next week and update this, but for now ? Am impressed about the sheer quality of this unit. If it performs as good as it looks, this is a winner!
Albert. EI7II.
Greg Mann –
This transformer with 260′ wire won me first place in single operator, 160M for Georgia, 2nd place in SE Division, and 9th place W/VE for ARRL DX 2021 de WC4Y
Thomas K. –
Rugged construction, excellent performance. Good stuff!
Manny Fonseca Jr –
Very Happy with the results! My second one from a great company.
Roman Tomas –
working well, quality is perfect