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EH Antennas for Hams

EH Antennas for Hams. September 2004 by Ted Hart W5QJR. Courtesy of EH Antenna Systems. What Is An EH Antenna?. It is a revolutionary concept that allows small antennas to outperform large antennas. EH Antenna – An Example Located at Eatonton, Georgia.

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EH Antennas for Hams

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  1. EH Antennasfor Hams September 2004by Ted Hart W5QJR Courtesy of EH Antenna Systems

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

  3. EH Antenna – An ExampleLocated at Eatonton, Georgia

  4. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size

  5. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size • + Low Height

  6. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size • + Low Height • + No Radials Required

  7. EH ANTENNAS ARE DIPOLES

  8. A 20 Meter EH Antenna

  9. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size • + Low Height • + No Radials Required • + Broad Bandwidth

  10. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size • + Low Height • + No Radials Required • + Broad Bandwidth • + High Efficiency

  11. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size • + Low Height • + No Radials Required • + Broad Bandwidth • + High Efficiency • + Low EMI

  12. What Are The Defining ParametersOf An EH Antenna?___________________________________________________________________________________________________ • Small Size • + Low Height • + No Radials Required • + Broad Bandwidth • + High Efficiency • + Low EMI __________________________________________________________________________________________________________ • = A Great Antenna for Hams

  13. 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

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

  15. L1 C1 Coax Phasing Coil L2 C2 The Evolution Of The EH AntennaL+L NETWORK

  16. L2 L1 Coax Phasing Coil C2 C1 The Evolution Of The EH AntennaL+T NETWORK

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

  18. EH Antenna Analysis Program

  19. 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

  20. EH Antenna Analysis Program

  21. EH Antenna Analysis Program C = 0.55*L/D*D + 2.06*D

  22. EH Antenna Analysis Program

  23. EH Antenna Analysis Program

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

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

  26. PREFERRED TEST EQUIPMENT

  27. 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

  28. COAX CHOKE

  29. 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

  30. 75 METER EH ANTENNA

  31. 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

  32. 75 METER TUNING COIL

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

  34. IMPEDANCE WITHOUT REACTANCE COIL

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

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

  37. EH Antenna Analysis Program

  38. HEIGHT VS. RADIATION ALONG THE GROUND.

  39. WEB SITE • www/eh-antenna.com

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