(2 customer reviews)


MEF-330-1K Multiband EFHW Antenna Transformer,  Covers 8 Bands / 80-10m / 1kW-max. /  NO TUNER needed / wire not included/one End Insulator included


SKU: MEF-330-1K Categories: ,


MEF-330-1K Multi-Band End Fed Half Wave Antenna Transformer

This is an End-Fed Half Wave antenna (EFHW) Transformer for frequencies between 3 and 30 MHz. To use it at any frequency in this 3-30MHz spectrum just add half wave long wire for the frequency of your interest. The benefit of the EFHW antenna is that it will be resonant on harmonically related frequencies.

  • NO TUNER needed!
  • NO counterpoise needed! (Grounding recommended)
  • Frequency coverage:3-30MHz
  • Just adding a wire radiator of ~130 feet makes this antenna resonant on 80/40/30/20/17/15/12/10m.
  • Wire of ~66 feet will give you low VSWR on 40/20/15/10m
  • Power Handling:1kW I.C.A.S
  • Weight: 0.95 lbs. (0.43kg)
  • Hardware: Stainless Steel
  • Connector: Silver/Teflon SO-239

For example, 7 MHz half wavelength is 20 meters or 67 feet of wire or two half wave on 14MHz, also it is four half waves on 28MHz. So, wire for 7MHz will give you low VSWR on 14 and 28MHz, 15m or 21MHz is also related as three Half Wavelength and there you might have low VSWR too. It all depends on height over the ground and objects around the antenna. 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 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, in “inverted “V” shape, Horizontal L, etc. Such antenna will not need radials and in most cases NO Tuner at all.  Be a HAM and do some experiment. Grounding at the lug next to the SO-239 connector is recommended! Long wires tend to collect electrostatic charge (usually when weather is stormy) which can produce ESD (electrostatic discharge) at the end of your cable and damage your equipment.

The longer wire will give you more harmonic related resonances, For example, Half Wave wire for 80m or 3.5MHz will give you (8) eight resonances up to 30MHz. See this picture of low  VSWR resonances taken with 130Feet (39m) of wire at only 20 feet (6 meters) above ground.

It starts from 6 feet (1.8m) at the transformer, and then it goes over the tree branch at about 20 feet (6m) and ending at only 10 feet above the ground.  Also, see the response of VSWR per band in other images, note that antenna is very low for 80m band and your  VSWR curve might be a bit different at your location. Always aim to put the wire higher and leave the wire a bit longer at the end in order to tune it at the desired frequency.


Shorter versions of antenna utilizing TRAPS and Resonators will be available soon.

Subscribe to our Newsletter on the bottom of this page to get more information about this and other antennas. Antennas are in production and first models out of many are coming soon.   Stay tuned…. 73  Danny Horvat, E73M/N4EXA (former Cushcraft Corporation antenna designer)

Gallery of VSWR images per band with 130 feet (39m) long wire at only 20 feet above the ground.



2 reviews for MEF-330-1K

  1. Dom, F4BWJ

    I’ve installed the MEF-330-1K with around 132ft of stainless 3mm diameter wire.
    The MEF-330-1K is installed at 1,10m from the ground the wire goes quite vertically to 5/6m high and the rest of the wire goes to 12/13m high on the top of a tree.

    First of all what is noticeable is the noise floor level which is lower than I got with other antennas such as G5RV, long Wire, dipole, Conrad Windom etc…
    With the EFHW antenna the noise level is around 53 to 55 on 80m during the day as I get 57 to 59 with other antennas.
    Also the received signals can be very strong in despite of low noise floor level (higher than a long wire or G5RV for example).

    From South West part of France, my first contacts with this antenna on 80m have been made with only 100W from my SDR MB-1 early in the morning with north American stations between 6:00am and 7:00am UTC (NY2PO -5843kms, KK6ZM/1 -5386kms, W1/DL4NAC – 5562kms…), New Zeeland station (ZL1AIX – 19187kms) and just this morning 11/03/2016 at 6:45 UTC Cayman Island (ZF2ZB in a tremendous pile up with big guns stations all over Europe!!! – 7771kms)..

    I’ve made some tests on 17m and 12m WARC Bands with success too (e.g. first contact on 12m band with CX7SS).
    The sole problem I encounter is with 30m band, SWR is around 2,7/3.0 and in despite the ATU transceiver is normally able to tune antennas with such SWR, it’ cannot match my EFHW antenna. This is not very important for me as I don’t use this band.

    In conclusion, very interesting beginnings for this homemade EFHW 132 ft. antenna fed with the MEF-330-1K transformer!!!

    NB: I apologize for my broken english in this review as I’m a French ham.

    Dom, F4BWJ.

  2. Marcius E. Chester

    Danny all I can say is “WOW” this
    MEF-330-1K Transformer attached to a 66′ 18g wire in a sloper/slanted L configuration up 35′ in a 40′ tree is the best antenna I have ever had. Due to living in a HOA development I’m not able to put a antenna on the roof. This transformer works perfect on 11 meters. Swr: 1.0: 26.965- 1.0: 27.405. Keep up the good work and think about building 64:1 transformers.
    Rev. Doctor MC. Big Mac-233
    Southern California

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