September 2004 by Ted Hart W5QJR 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  

What Are The Defining Parameters Of An EH Antenna Small Size

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

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

EH ANTENNAS ARE DIPOLES

A 20 Meter EH Antenna

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

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

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

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

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

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

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

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

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

EH Antenna Analysis Program

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

EH Antenna Analysis Program

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

EH Antenna Analysis Program

EH Antenna Analysis Program

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

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

PREFERRED TEST EQUIPMENT

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

COAX CHOKE

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

75 METER EH ANTENNA

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

75 METER TUNING COIL

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

IMPEDANCE WITHOUT REACTANCE COIL

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

IMPEDANCE WITH REACTANCE COIL 3 dB Bandwidth = 269 KHz

EH Antenna Analysis Program

HEIGHT VS. RADIATION ALONG THE GROUND.

WEB SITE www/eh-antenna.com