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Been doing some reading on these EH antennas. http://www.eh-antenna.com/newAM.htm The claim is a efficiency of 98 %, what gets more interesting is that each cylinder of the antenna is 48 inches long. There are two cylinders this making the radiated portion 96 inches long..well within the 3 meter limit. MORE
So add a phasing coil and and a tuning coil and one is still under the 3 meter limit. If this is to hold true and the “NORMAL” 3 meter antenna is 4 % efficient and this EH antenna is purported to be 98%. Imagine the implications this could have for part 15 users. I have been looking on the internet to see if there are any other EH antenna users , using this antenna for Part 15 AM use and found none…so far. I did see these antennas selling (for ham use) at a convention in JAPAN. My question is, what are your thoughts and has any Part 15 AM users actually used these antennas for Part 15 use. And what are your results with these verses a “traditional” 3 meter part 15 am antenna.
Total posts : 45366Found another link on how to build one.
Total posts : 45366can be found on the pCS electronics forum here:
http://www.pcs-electronics.com/phpBB2/viewtopic.php?t=1092
Photos included.
And of course, the commercial version here:
http://www.isotronantennas.com/ambroad1.htm
Experimental broadcasting for a better tomorrow!
Total posts : 45366“Total Heat Loss (Watts) = 13.15”
Errr, no good for us 🙂
I actually saw your second site the other day and bookmarked it as a potential idea. But after seeing losses in the system, I’m not seeing that it would help Part 15 broadcasters.
Total posts : 45366I found another site, someone is selling the EH antenna for $550 each. I think it would be feasible to build one ourselves for much less. This site also has some good information on part 15 and other not so part 15 items.
http://groups.msn.com/GospelRadio/asmallamantennathatworks.msnw
Total posts : 45366I did some reading up on it too,very interesting-indeed! It would be the answer to a higher efficiency antenna if all they claim is true. The idea that it is not a ground return system makes it desireable but I dont think his gain claims will hold water. Still,it would be a hoot to build one and see what it will do. Its too cold for antenna work here,but I may give it a whirl this summer. I guess you could call it a push-push antenna?!!? LOL Regards,Lee
Total posts : 45366A fairly long thread on this subject is available at
http://www.part15.us/node/1014
Bottom line is that these antennas are not really better than any other radiators of the same length and loading parameters. The requirement as shown in one earlier link to mount them rather high off the ground, and to use a long coaxial transmission line whose outer conductor must be connected to an earth ground means that much of the radiation from the installation will be made from the coax line, itself.
The paper on this topic by the consulting firm of DuTreil, Ludin and Rackley makes interesting reading.
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Total posts : 45366So that means having a tower mounted transmitter would be worthless since you aren’t getting the long coax radiator that they want.
Total posts : 45366I think the suggestion is to install a ground lead leading from the Part 15 tx chassis to an r-f ground, either directly or by bonding it to the grounded tower.
So again there will be a source of extra radiation from that configuration, because it comprises a radiating length longer than the 3 meters permitted by 15.219.
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Total posts : 45366The theoretical efficiency of an electrically short antenna is proportional to the effective volume of the antenna. A number of short antenna designs have appeared during the past two decades that claim to exceed the theoretical limits of short antennas. The oldest of these is the Crossed Field Antenna (CFA), which was introduced to the public in an article in “Wireless World,” a British electronics magazine, in 1989. The authors claimed that they had eliminated the near field, which is the interface between the antenna and free space. With the CFA, the far field is generated right at the antenna, and so the antenna size is unimportant. It is possible to make the CFA as small as desired without any loss in efficiency. Most antenna experts have thought that this is nonsense. The question was settled recently by Prof. Valentin Trainotti, the world’s leading authority on short AM broadcast band antennas. In the September, 2006, issue of IEEE Transactions on Broadcasting, Trainotti gave a thorough theoretical analysis of the CFA. The CFA is no more efficient than other small antennas the same size. It, of course, has a near field, like other antennas. This finding has no effect on the promoters of the CFA, because they believe that they have discovered a new physical principle which is not explained by conventional antenna theory.
The EH antenna was developed by an author of several articles about the CFA. He simplified the structure of the CFA considerably to make the EH, but claims that the EH works on the same principles as the CFA. The EH antenna also has no near field, and it can also be made arbitrarily small without any loss in efficiency.
The promoters of the Isotron antenna claim that their antenna works according to conventional antenna theory, thus avoiding some of the criticism the EH and the CFA have received. They say that the good performance of their antenna is because of its large cross-sectional area. It’s true that a fatter short antenna works better than a thin one, but the cross-sectional area does not explain the performance of the Isotron.
Another short antenna that is less well-known than the others is the CWTH (Contrawound Toroidal Helical) antenna. The “inventor” is a registered patent attorney with a PhD in EE. The theoretical explanation of this antenna in the patent starts out pretty well, but falls apart when the inventor tries to explain why his antenna is more efficient than other antennas the same size. The patent is one of the most intricate I’ve ever seen. The inventor is lucky that he’s a patent attorney himself. Maybe he wouldn’t be able to afford to pay somebody else to draft such an elaborate patent.
All of these antenna designs actually perform better than ordinary short antennas the same size. This is not because of any unusual properties of the antennas themselves, but because they all involve the use of a long radiating conductor that is not counted toward the antenna length. Part 15 AM enthusiasts are very well aware of this trick. Well-known authors of articles about Part 15 AM antennas have called it “whip and mast” (“Crash” Knorr) and “elevated” antenna (Richard Fry).
CFAs have been found to work much better than other short antennas the same length. The promoters claim that a 6.5 meter CFA works better than a quartwe-wave broadcast tower. Actual measurements show that the CFA performance is typically 6 dB to 10 db poorer than a quarter wave tower. Even so, this is pretty good, and such a short antenna should not work that well. The CFA proponents do a couple of tricks to improve the performance of their antenna. One trick is to mount the antenna on a flat roof with a copper ground plane. The copper is connected to earth ground through several metal straps along the walls of the building on which the antenna is mounted. Most of the radiation comes from the straps. This trick is well-known in Part 15 AM. Some Part 15 AM transmitter manufacturers recommend that a long conductive ground path be used between the transmitter and earth ground (supposedly for “lightning protection”). The “whip and mast” antenna is a grounded vertical dipole, and the longer the conductive path to ground, the greater the antenna efficiency.
The CFA promoters also use another trick that I’ve never heard has been used in Part 15 AM. In at least one case, the CFA was mounted close to the original quarter wave antenna (of an AM broadcast station) that was disconnected from the transmitter for the purpose of performing the CFA test. The CFA coupled energy to the broadcast tower, which radiated the RF energy with higher efficiency than if the CFA were used alone. In another case, a CFA mounted at the surface of the earth was located near a microwave antenna tower with a height approximately a quarter wavelength of the carrier frequency of the signal to be transmitted. While, structurally, the use of a large resonator near the short antenna seems to be different from the “whip and mast,” it is really equivalent. The principle of the “whip and mast” is to use a long radiating conductor that is not counted as part of the antenna length.
The other antennas I mentioned work the same way as the CFA. They all have something that you are not supposed to pay any attention to (like the man behind the curtain). They all have a long radiating conductor that is much longer than the “antenna” itself. The CFA has attracted more attention than the others because it apparently has strong financial backing, allowing the promoters to perform CFA experiments all over the world.
Total posts : 45366On January 24th, the FCC issued a citation to Iglesia de Dios Ebenezer in Oceanside, CA, (suburban San Diego, to the north) for operating a Part 15 AM station on 1610 kHz with an overly long ground lead. According to the citation, the antenna was about 3 meters long, but the “ground lead” was about 30 meters long. The citation may be viewed on http://www.fcc.gov on the Enforcement Bureau web page under Field Actions.
Enforcement actions related to Part 15.219 are rare, and the enforcement is inconsistent. Sometimes “whip and mast” antennas are allowed by field agents and sometimes they are not. Looking at the SSTran web site, http://www.sstran.com, the construction article for the antenna that is recommended for use with their transmitter describes a whip and mast. On the Rangemaster web site, http://www.rangemaster.com, there are two diagrams showing two variations of the whip and mast antenna that are recommended to be used with their transmitter. There are also photagraphs of Rangemaster transmitters mounted on tall metal towers. So, at least these two manufacturers are recommending the use of the whip and mast by their customers.
I don’t know who the manufacturer of the transmitter used at the church is, or the nature of the 30 meter ground lead mentioned in the citation. I’d like to find this out, since it would be of interest to the users of this web site. Unfortunately, I don’t quite know how to pose the question delicately enough.
Total posts : 45366Uh, er, um… that 90 feet!!! Holy Schnikies!!!
While not stated explicitly in this citation, there have also been versions of 219 that specify a max height of a Part 15 intentional radiator at 50 feet.
Not exactly “whip and mast,” more like whip and mast and tower – not exactly a typical experimental approach 🙂
Also interesting that it’s a Citation, not an NAL or NOV.
More interesting links
PDF Version of this Citation
Citation on the FCC Site
Link to the enforcement listings page
Link to the Forefiture Orders (aka heavy business) page*****************************************************************
Before the Federal Communications Commission Washington, D.C. 20554
In the Matter of File No.: EB-06-SD-423
Iglesia de Dios Ebenezer Citation No.: C20073294003
Oceanside, California 92054CITATION
Released: January 24, 2007
By the District Director, San Diego District Office, Western Region,
Enforcement Bureau:1. This is an Official Citation issued pursuant to Section 503(b)(5) of
the Communications Act of 1934, as amended (“Act”), to Iglesia de Dios
Ebenezer for violation of Section 15.219(b) of the Commission’s Rules
(“Rules”).2. The Enforcement Bureau’s San Diego office received a complaint that an
unlicensed AM broadcast station was operating on 1610 kHz at 141
Canyon Drive, Oceanside, California. On November 2, 2006, agents from
the San Diego Office confirmed that an AM broadcast station was
operating on 1610 kHz at 141 Canyon Drive, Oceanside, California, that
did not conform with the requirements of Section 15.219(b) of the
Rules.3. Section 15.219(b) of the Rules states “[t]he total length of the
transmission line, antenna, and ground lead (if used) shall not exceed
3 meters.” The antenna being used by the station appeared to be
approximately 3 meters long, however, the total length of the ground
lead was approximately 30 meters. Consequently, the station is
operating in violation of Section 15.219(b) of the Rules.4. Violations of the Act or the Commission’s Rules may subject the
violator to substantial monetary forfeitures, seizure of equipment
through in rem forfeiture action, and criminal sanctions, including
imprisonment.5. Iglesia de Dios Ebenezer or their representative may request an
interview at the closest FCC Office, which is Federal Communications
Commission, 4542 Ruffner Street, Suite 370, San Diego, California
92111. You may contact this office by telephone, XXX XXX-XXXX, to
schedule this interview, which must take place within 14 days of this
Citation. Iglesia de Dios Ebenezer may also submit a written statement
to the above address within 14 days of the date of this Citation. Any
written statements should specify what actions have been taken to
correct the violations outlined above. Please reference file number
EB-06-SD-423 when corresponding with the Commission.6. Any statement or information provided by you may be used by the
Commission to determine if further enforcement action is required. Any
knowingly or willfully false statement made in reply to this Citation
is punishable by fine or imprisonment.7. IT IS ORDERED that copies of this Citation shall be sent by First
Class U.S. Mail and Certified Mail, Return Receipt Requested, to
Iglesia de Dios Ebenezer at their record of address.FEDERAL COMMUNICATIONS COMMISSION
William R. Zears Jr.
District Director, San Diego Office
Western Region
Enforcement Bureau47 U.S.C. S 503(b)(5).
47 C.F.R. S 15.219(b).
47 C.F.R. S 15.219(b).
47 C.F.R. S 1.80(b)(3).
47 U.S.C. SS 401, 501, 503, 510.
47 U.S.C. S 503(b)(5).
See Privacy Act of 1974, 5 U.S.C. S 552a(e)(3).
See 18 U.S.C. S 1001 et seq.Experimental broadcasting for a better tomorrow!
Total posts : 45366the problem with this is he more than likely was not doing whip+mast. it was more whip + ground wire. 90ft sounds like he had it mounted on the church roof and ran a long ground wire to earth. I think had it been mounted on a 15-20ft 1-1/2″ Dia. Pipe instead of 90ft of wire from a church roof then he would not have been bothered. sounds like the agent thought he was trying to pull something over on him. the whip and mast approach, the true whip and mast approach has past muster lots of times. as otheres have stated. details, we need details. transmitter? homebrew? type certified? did maybe have it cranked a little higher than he should have? was he a pirate operator in the past and had problems with the FCC before?
These are questions that need answers before we can infer anything from this.
Thank You,
Rev. Robert P. Chrysafis
Universal Life Ministries
http://www.ulc.orgModerator Hunterdonfree
http://groups.yahoo.com/group/hunterdonfree
Total posts : 45366A couple of people visited Iglesia de Dios Ebenezer in Oceanside, CA, at my request, and this is what they found out:
The installation is still there, but I don’t know if it is still operating. The church is a large, single-story, building that includes a school. The congregation appears to be large. The pastor and other church leaders were not available on the day of the visit, but there were several ordinary parishioners who knew that their radio station had a problem with the government. They pointed out the antenna. The top of the church roof appears to be about 30 feet high. A long, thin, pipe, perhaps two inches in diameter, is mounted on the roof. The pipe extends far up into the air. The visitors could not guess how high the pipe extended. They only said it is “very high.” We know from the citation that it is about 30 meters above the earth. On top of the pipe, a thin whip antenna, perhaps a quarter inch in diameter, was visible. This must have been the CB whip connected to the top of the transmitter. The visitors could not tell me anything about the conductive path from the bottom of the pipe to earth ground.
So, it appears that the FCC does not buy the notion that that the top of the pipe is the “ground” to which the “ground lead” is connected. In this case, they considered the wire from the transmitter to the pipe, the entire length of the pipe, and the conductive path from the bottom of the pipe to earth ground, to be the ground lead, which is about 30 meters in total length.
There seems to be some confusion about the name “lglesia de Dios Ebenezer.” It is not the name of an individual, or even the name of a particular congregation. It is the name of a Protestant sect that has several churches in various places in this country. The entity that was cited was the Iglesia de Dios Ebenezer church in Oceanside, CA.
Total posts : 45366Hmmmm………………………………….
I might be in trouble if I install in a similar fashion.
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