Also have a look at https://worldwideantennasystems.com/specs/

They claim a "ground wave field strength of 250-300 mV/m at 1 kilometer with 1 kilowatt of input power", but without mentioning the exact operating frequency (525 - 1705 kHz).

This is however very close to the free space fieldstrength:

EIRP = (e*d)^2/30 where e = electric field strength in V/m and d = distance in m

EIRP = (0.25*1000)^2/30 = 2.08kW

Assuming that the antenna gain is 3 (as for a short vertical monopole) 1kW input power equals 3kW EIRP.

Ignoring any ground wave attenuation the antenna efficiency would be 70% !!!

For an antenna that is between 10% (at 1705kHz) and 3% (at 525 kHz) of the wavelength.​


Allow me to have some doubts ...


73, Rik  ON7YD - OR7T


Van: [email protected] <[email protected]> namens Dick Bingham <[email protected]>
Verzonden: zaterdag 18 februari 2023 20:34
Aan: D.J.J. Ring, Jr.
CC: Ken Roberson via 600MRG
Onderwerp: Re: [600MRG] Radio engineer Grady Motes and the HEBA efficient small size medium wave antenna
 
Hi

Possibly interesting. I started watching the video and quit after maybe 5-minutes.
Talking-heads BS !!

I located this Patent Office info  for the HEBA antenna ===>
https://uspto.report/patent/grant/10,461,430

that may have more useful info.

73  Dick/w7wkr at CN97uj

On Sat, Feb 18, 2023 at 1:40 AM D.J.J. Ring, Jr. <[email protected]> wrote:
Radio engineer Grady Motes and the HEBA efficient small size medium wave antenna.

https://youtu.be/TY1TArbqEfI 


Pleasing Audio Processing with Mike Erickson - TWiRT Ep. 444


Description

The HEBA - AM's Real Estate Relief - with Grady Moates - TWiRT Ep. 460

TWiRT - This Week in Radio Tech


Grady Moates is a “hands-on” broadcast engineer. Known widely for his audio processing expertise, Grady’s attention has more recently been on proving the performance of a novel antenna design. The High Efficiency Broadband Antenna (HEBA) - after years of additional research and real-world testing and proving - is now FCC approved. Grady explains how a HEBA help AM stations, especially those with real-estate opportunities.

Show Notes:

HEBA (High Efficiency Broadband Antenna) Specs

HEBA antenna under construction

Photos, diagram, and rendered video of HEBA antenna
...more

TWiRT - This Week in Radio Tech
2.33K subscribers
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