1 / 40

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.

nicole
Download Presentation

EH Antennas for Hams

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  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

More Related