MEF-330-1K-ICAS

Description

EFHW transformer MEF-330-1K-ICAS (56:1) ratio 3-30MHz 1kW ICAS

“This is the first EFHW antenna transformer we introduced back in 2015, and we are proud to celebrate its 10th anniversary. Over the years, we’ve made subtle enhancements to ensure top performance: the transformer has been refined, and was reviewed by ARRL QST Magazine, and you can read the detailed review here.”

Comes with one end insulator and two wire clamps!

The MEF-330-1K-ICAS is a high-performance End-Fed Half-Wave (EFHW) antenna transformer designed for amateur radio operators. Covering the 80m–10m bands and frequencies in between, it efficiently transforms a high impedance (~2800 Ohms) at the end of a half-wave radiator to 50 Ohms. With an average insertion loss of just ~0.6 dB from 3.5–30 MHz, it ensures excellent signal performance.

Key Features

• Transformer Ratio: 56:1 (better match on lower frequencies than 49:1 ratio)
• Ferrite Cores: Two 2.4-inch ferrite cores for enhanced efficiency (better than FT-240-43 cores)
• Insertion Loss: Extremely low (~0.6 dB on average across 3–30 MHz)
• Power Handling:
  • 1kW I.C.A.S (Intermittent Commercial and Amateur Service)
  • 1000W SSB
  • 350W CW
  • 250W FT8 digital mode intermittent or 100W continuous
• Durable Construction:
  • Housing: ABS
  • Hardware: Stainless steel
  • Connector: Silver/PTFE (Teflon) SO-239
• Frequency Coverage: 3–30 MHz
• Ease of Use:
  • No tuner or counterpoise needed for most installations
  • Imagination-driven wire installation options (horizontal, vertical, sloping, inverted “L,” horizontal “L,” inverted “V,” etc.)

Wire Length Calculation

• In Feet: Length = 468 ÷ Frequency (MHz)
• In Meters: Length = 142.5 ÷ Frequency (MHz)

Tip: Always cut the wire slightly longer for fine-tuning, as performance depends on installation height, nearby objects, and environmental factors.

Installation Notes

1. Tuning: Adjust the wire length to achieve your desired frequency. Variations in VSWR curves may occur depending on location and setup.
2. Grounding:
   • Ground the cable at the entrance to your home to minimize interference.
   • Ground the lug near the SO-239 connector to prevent electrostatic discharge (ESD), especially during stormy weather.
3. Harmonic Resonances: A longer wire provides more harmonic resonances. For example, an 80m half-wave wire (3.5 MHz) can produce up to eight resonances up to 30 MHz.

Experiment and Explore

The MEF-330-1K-ICAS encourages creative installation and experimentation. Whether you’re new to amateur radio or a seasoned operator, this antenna transformer provides robust performance and flexibility for diverse operating environments.

Unleash your creativity and enjoy the thrill of experimentation with this versatile EFHW antenna transformer!