2. September 2004 by Ted Hart W5QJR
EH Antennas for Hams
September 2004 by
Ted Hart W5QJR
Courtesy of
EH Antenna Systems

3. What Is An EH Antenna?
It is a revolutionary concept that allows small antennas to outperform large antennas.

4. EH Antenna – An Example Located at Eatonton, Georgia

5. What Are The Defining Parameters Of An EH Antenna
Small Size

6. What Are The Defining Parameters Of An EH Antenna
Small Size
+ Low Height

7. What Are The Defining Parameters Of An EH Antenna
Small Size
+ Low Height
+ No Radials Required

8. EH ANTENNAS ARE DIPOLES

9. A 20 Meter EH Antenna

10. What Are The Defining Parameters Of An EH Antenna
Small Size
+ Low Height
+ No Radials Required
+ Broad Bandwidth

11. What Are The Defining Parameters Of An EH Antenna
Small Size
+ Low Height
+ No Radials Required
+ Broad Bandwidth
+ High Efficiency

12. What Are The Defining Parameters Of An EH Antenna
Small Size
+ Low Height
+ No Radials Required
+ Broad Bandwidth
+ High Efficiency
+ Low EMI

13. What Are The Defining Parameters Of An EH Antenna
Small Size
+ Low Height
+ No Radials Required
+ Broad Bandwidth
+ High Efficiency
+ Low EMI
__________________________________________________________________________________________________________
= A Great Antenna for Hams

14. The Number 1 Question, does It Work?
* FCC Type tests prove it is a very good AM Broadcast Antenna
* Many Hams use home made EH Antennas
*Companies in Italy and Japan manufacture EH Antennas for Hams
*EH Antennas are in commercial use
* EH Antennas will be the preferred choice in the future for most communications applications

15. QUESTION #2 – HOW DOES IT WORK?
HIGH CURRENT
H FIELD
E FIELD

16. The Evolution Of The EH Antenna L+L NETWORKC1 C2 L1 L2
Phasing Coil
Coax

17. The Evolution Of The EH Antenna L+T NETWORK
Coax C1 C2 L1 L2
Phasing Coil

18. The Evolution Of The EH Antenna *STAR* EH ANTENNA
CYLINDER
PHASING COIL
CYLINDER
TUNING COIL
COAX
REACTANCE COIL

19. EH Antenna Analysis Program

20. EH Antenna Analysis Program
Measuring 3 dB Resistance
Definition Q=XL/R=F0/BW
Therefore: R = BW*XL/ F0
Radiation Resistance = 3 dB Resistance – Loss Resistance

21. EH Antenna Analysis Program

22. EH Antenna Analysis Program
C = 0.55*L/D*D *D

23. EH Antenna Analysis Program

24. EH Antenna Analysis Program

25. EH *STAR* ANTENNA CYLINDER PHASING COIL CYLINDER TUNING COIL COAX
REACTANCE COIL

26. ROLL YOUR OWN EH ANTENNA
STEP 1- OBTAIN TEST EQUIPMENT
SIGNAL GENERATOR
FIELD STRENGTH METER
VSWR BRIDGE
IMPEDANCE BRIDGE (NICE)

27. PREFERRED TEST EQUIPMENT

28. ROLL YOUR OWN EH ANTENNA
STEP 2 – BUILD COAX CHOKE
ABOUT 1/8 WAVELENGTH OF COAX WOUND IN A COIL
LOCATE ABOUT 3 FEET BELOW THE ANTENNA

29. COAX CHOKE

30. ROLL YOUR OWN EH ANTENNA
STEP 3 - ASSEMBLE THE ANTENNA
DO NOT TRY TO MAKE THE FIRST ONE PRETTY –USE ALUMINUM FOIL OVER PLASTIC PIPE
USE 2 TURN FEED TAP –
NO SOURCE COIL YET

31. 75 METER EH ANTENNA

32. ROLL YOUR OWN EH ANTENNA
STEP 4 A - TUNE THE ANTENNA
MEASURE OPERATING FREQUENCY WITH FIELD STRENGTH METER –
TAP TOP OF TUNING COIL TO CHANGE FREQUENCY

33. 75 METER TUNING COIL

34. ROLL YOUR OWN EH ANTENNA
STEP 4 B - TUNE THE ANTENNA
PLOT IMPEDANCE or COMPARE MAX RADIATION AND MINIMUM VSWR FREQUENCIES

35. IMPEDANCE WITHOUT REACTANCE COIL

36. ROLL YOUR OWN EH ANTENNA
STEP 4 - TUNE THE ANTENNA
C – INSTALL SOURCE COIL
D – ADJUST FEED FOR 50 OHMS
E – RECORD IMPEDANCE PLOT

37. IMPEDANCE WITH REACTANCE COIL
3 dB Bandwidth = 269 KHz

38. EH Antenna Analysis Program

39. HEIGHT VS. RADIATION ALONG THE GROUND.

40. WEB SITE
www/eh-antenna.com