K4EDF End-Fed HF Antenna Four-Band End-Fed Antenna 40m,20m,15m,10m, 100w
Improved by BD5IK this HF End-Fed that covers 40-10m, resontant on 40m, 20m, 15m, 10m on HF. This antenna is the original design by K4EDF and it works very well on those bands.
K4EDF is a four-band end-fed antenna.
The advantage is that it has a very wide working bandwidth compared with other types of antennas (refer to the measured SWR graph). Normally, the natural resonance is more than 1 meter above the ground.
On the frequency. And the height change does not affect the resonance point very much, so it can be used without trimming, and the 40-meter band operates at half wavelength, the 20-meter band operates at one wavelength, and the 15-meter band at one-half wavelength. Working, the 10 meter band operates at two wavelengths, the four waves are naturally resonant and the gain radiation efficiency is still very high, very suitable for a novice entry antenna (without trimming).
The disadvantage is that the matching method is to use a high-ratio conversion balun. The heat loss is relatively large due to the ratio of the turns ratio and the magnetic flux density and the upper limit of the magnetic flux operating frequency. Therefore, this antenna is very suitable for beginners (not suitable for long-term continuous launching). , suitable for interval transmission and reception), amateur band SDR reception. There is no problem in receiving broadcasts, and it is also suitable for broadcasters.
The custom magnetic ring currently used reduces the loss to the lowest limit, and the actual test is safely transmitted with 100W SSB for 30 minutes! (Normal test balun only takes 10 minutes to continuously emit normal temperature and is qualified), we are all passed the super-strength violence test!
2.5 square MM multi-strand pure copper wire upgraded vibrator increases working bandwidth and tensile strength. Low standing wave with wider operating bandwidth.
It is designed with M connector. Large magnetic ring (loss is minimized) plus PCB are used to fix balun.
- Four-Band: 7MHZ 14MHZ 21MHZ 28MHZ
- Standing Wave: Less than 1
- Withstand Power: 100WPEP
- Balun Insertion Loss: about 1.5DB
- Vibrator with 2.5 square MM pure copper multi-strand line (UV-resistant for all-weather outdoor long-term erection)
- Length of Antenna: about 20 meters
- Installation Way: Horizontal Installation, Incline Installation and Vertical Installation
- 1 x End Fed Antenna