MEF-330-2K Multi-Band End Fed Half Wave Antenna Transformer
This is an End-Fed Half-Wave antenna (EFHW) transformer covering 3-30Mhz 80/40/30/20/17/15/12/10m amateur bands (used in EFHW-8010-2K model) or any frequency in between. It transforms high impedance ~3000 Ohms at the end of the 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 ~132 feet makes this antenna resonant on 8 bands.
- Frequency coverage: 3-30MHz
- Power Handling: 2kW I.C.A.S
- Weight: 1.25 lbs. (0.7kg)
- 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 the antenna will be working on multiple frequencies. Half-wave for 80M (~132 feet) will be half-wave on 80M and two (2) half-wave on 40M band etc. If you desire to use it on any particular frequency, just cut the half-wavelength wire for that frequency or any frequency from 3-30 MHz. 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 the weather is stormy) which can produce ESD (electrostatic discharge) at the end of your cable and damage your equipment.