Description
MEF-330-2K-Plus Multi-Band End Fed Half Wave Antenna Transformer 49:1 Ratio
Features massive ferrite core weighing 1.25 pounds (0.54kg) and very low Insertion loss ~0.5dB
This is an End-Fed Half-Wave antenna (EFHW) transformer covering 80/10m amateur bands or any frequency in between. It transforms high impedance ~2500 Ohms at the end of the half-wave radiator to 50 Ohms and features very low insertion loss. Average insertion loss from 3-30 MHz is ~ 0.5 dB
- NO TUNER needed!
- NO counterpoise needed! (Grounding recommended)
- Frequency coverage of the transformer only: 3-30 MHz
- Power Handling: 2kW I.C.A.S (500W at FT8 mode)
- Polycarbonate housing
- Hardware: Stainless Steel
- Connector: Silver/PTFE (Teflon) SO-239
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 80m (~133 feet) will be two half-waves on 40m and four (4) half-wave on the 20m band etc. 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 the 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 radio amateur 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.
davidmarksamsell –
Quality built EFHW antenna transformer with associated mounting bracket/hardware. Item was quickly received and packaged very well in transit. Thank you. Dave, AC3HT
Jack Zukowski Wa1ngh –
This is the second EFHW transformer I have purchased from MyAntennas. The quality just keeps getting better! I was a skeptic when I bought the first one, my skepticism is long gone. It turned out to be the best 160 meter I had ever built, and I had put up many over the last 50 years. It was no surprise that this would be any different. I cut this antenna for 40 meters. The 40, 20, 15, and 10 meter bands did not require any tuner. The 12, 17, and 30 meter do, which is easy to understand. My next experiment will be to add a couple of different spokes and see what transpires. A great antenna, made easy with these EFHW transformers! Tnx,Jack
Craig Williams –
Enjoying 2 of them
Dave G. –
Works great am talking to many new countries.
Robert Eggleston –
Excellent Well made works perfectly as advertised
Wayne Mackin –
This is an excellent EFHW transformer – I use an old Dentron Super Tuner with mine on a 20 meter wire (40m EFHW configuration), and have been able to effectively use all bands from 10m through 40m.