END FED (EFHW) transformer

Product detailed description

END FED (EFHW) Transformer

New design 2025

- more massive boxes, thicker walls
- brass bushings for lid screws
- Uniform box design across all models
- new power limits
- wider choice of mechanical designs
- choice of pressure valve design
- choice of Amphenol N connector
- MINI version also available in caliper mount version
- overall precision design

suitable for END FED (EFHW) antennas - end-fed half-wave antennas

Specifications:
- impedance transformation ratio 1:64 or 1:49 depending on the variant
- compensation capacitance 100 pF / 10 kV
- input impedance 50 Ohms
- Power load up to 300 W PEP max (SSB 300 W / CW 150 W / DIGI 90 W)
- large ferrite toroid 1x FT-240
- mechanical design for hanging by rope
- PL input connector (UHF)
- antenna radiators are connected to M4 screws and secured with wing nut
- fasteners are stainless steel
- box dimensions 105x105x60 mm
- the box has IP-65 protection
- the box is equipped with a pressure valve
- weight 0,4 kg

The box is equipped with a pressure valve.
The function of the pressure valve - if the instrument box is exposed to temperature changes - e.g. the difference between day and night temperatures or if heat is generated in the box during operation and the box cools down after operation - pressure changes and water vapour condensation occur in the sealed box.
In some cases, a vacuum may even be created, which can cause dust and moisture to enter.
Installing a pressure equalizing valve is a very simple way to provide ventilation while preventing vapor condensation and dust from entering the enclosure.

Attach the coaxial cable to the transformer so that it does not hang by its own weight on the connector.