1. Small HF Antennas NNN0OAA
Magnetic Loops
Crossed-Field (CFA)
E-H (“STAR”)

2. Magnetic Loops Not magic Keep losses low Capacitor challenges Low loss
High voltage
High capacitance value
Remotely variable

3. Capacitor Solution #1 “Dielectric loaded” variable capacitor
Jef Verborgt, SWL

4. Capacitor Solution #2 From ARRL Antenna Book Richard Plasencia, W0RPV
Aluminum plates separated by .063” glass
4-1/2” x 4-1/2” and .063” glass (K = 8, 300 V/mil)
16 to ,000 volts
300 V/mil x 63 mils = 18,900 V
.224 x 8 x (4.5” x 4.5”)/.063” = 576 pF

5. Capacitor Solution #3 Glass dielectric (K=8) Art Heft, W2BRI
Electric screwdriver
Nylon threaded rod drive

6. Capacitor Solution #3a Glass dielectric (K=8) Art Heft, W2BRI
Electric screwdriver
Nylon threaded rod drive

7. Capacitor Solution #4 Integrated Capacitor
Bernie Wright

8. Crossed Field Antenna E-H Origin?

9. Crossed-Field Antenna Maurice Hately, GM3HAT and Fathi Kabbary

10. Does the CFA work? Egypt Australia Amateurs VK2EDB on 20 Meters
San Remo (Italy)
AM broadcast, 6 meters tall
Supressed unwanted sky wave
A viable alternative (for AM broadcast) to the driven mast antenna

11. E-H Antennas Ted Hart, W5QJR
“For more than 120 years all antennas have been Hertz antennas, except the Crossed Field Antenna. In the future all antennas will be EH Antennas.”

12. E-H Antenna STAR configuration

13. E-H Antenna STAR configuration

14. E-H Antenna
STAR configuration

15. E-H Antenna STAR configuration
Choke: See

16. How does it work? Synthesizes EM wave … or …
Common mode current on coax
5%? 11%? or more?
See: Lloyd Butler VK5BR

17. Evaluations Ted Hart, regarding AM broadcast version
Few dB > than ¼ wave vertical with 120 radials, near field
Steve Katz, WB2WIK/6
On air: -20 dB vs. roof-top vertical
On air: -20 to –35 dB vs. beam
Anechoic chamber: -20 to –22 dB vs. ½ wave dipole
Adam MacDonald, N1GX (and WA1ZEB), 3/2003
Compass Rose (near Edwards AFB)
-28 dB (zero length coax)
Significant radiation from coax
Desert site, south of California City, CA
H R Henly, G3IHR
The 20m and 40m versions were tested.
The antennas both faired well compared to a 12AVQ and a G5RV
when operated under similar conditions, i.e. at a similar height and position with relation to surrounding objects

18. E-H at NNN0OAA? So far … maybe –20 dB
Compared to semi-indoor inverted-L
70' indoor horizontal segment at 18 feet
distorted external vertical feed 20 feet long
8’ ground rod, 80’ and 95’ radial
SGC230 autotuner
EH on deck railing at 10 feet
EH in basement 22” off floor
EH in basement on floor
Two-way contacts were made

19. Suggestions Magnetic Loop CFA E-H Throw a wire out the window
Build it … correctly!
CFA
Wait … watch the debate, litigation, etc.
E-H
Build one for FUN and follow the “soap opera” at
SWR meter (a must), FS meter, SWR analyzer
Throw a wire out the window

20. URLs N1GX (E-H) “Compass” N1GX (E-H) “Desert” KB1EGI (E-H) “Pspice”
N1GX (E-H) “Desert”
KB1EGI (E-H) “Pspice”
Bernie Wright (Magnetic Loops)