Talk:Crossed field antenna

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Why did user delete the reference from the expert witness at the hearing regarding the planning permission for the MusicMann279 to build a CFA on the Isle of Man? (Ghostoffcoast (talk) 09:59, 24 January 2008 (UTC))

The document was supplied confidentially to IMIB by a consultant. The link shown is to an obsolete issue of the document which misprepresents the views supplied. —Preceding unsigned comment added by (talk) 10:36, 5 February 2008 (UTC)

This Jack Stone reference; has he really got things right? He was celebrating the 20TH ANNIVERSARY of the CFA patent dated 1989 in August 2006.

Improperly deleted link[edit]

The deleted document is a written statement by the IMIB expert witness at the public and open hearing to investigate a building permission for the broadcasting company IMIB to construct its transmission facility on the Isle of Man using a CFA. Objectors tried to prevent this to happen by claiming that the CFA did not work.

There is absolutely no reason for deleting that document. During the court case there was some objection regarding someone's views, but only regarding the small section 9.3 of the document and that was verbally altered during the hearing. No one objected in court or afterwards to the measured data presented in section 8 of it; so those numbers are correct. There was never any reissue of the document as suggested. That is because it is a written statement done by the IMIB’s expert witness and presented as evidence in the open court to be examined there and then. That document is of course official and also published in antenneX Online Magazine.

At a distance of 1.2 km from the antenna, these data indicate a field-strength of 6 V/m for a radiated power of 500kW for the planned CFA. It is a well known fact that the highest possible theoretical field strength for the standard ¼ wavelength high mast radiator is 5.86 V/m for that same radiated power and distance.

The IMIB sent their Director of Engineering and the Expert Witness to investigate another Egyptian CFA located in the south east of Egypt, this one is standing directly on the ground in a desert.

In section 6 of the document experimental data from this investigation is presented in Table 2. It is a well known fact that the highest possible theoretical field strength for the standard ¼ wavelength high mast radiator over a perfectly electrically conducting ground path is 1.99 V/m for the radiated power of 10kW at a distance of 500 meters.

The readings in Table 2 for 10kW radiated power at 500 meters distance in four symmetrical directions around this CFA were 2.13 V/m; 2.70 V/m; 2.10 V/m and 2.15 V/m over a desert ground path.

This was measured with a more then adequate SWR 1.6 bandwidth of 31 kHz (Table 3) at the operating frequency of 603 kHz. The over all height above ground for this CFA is 9.4m (0.048WL).

The link to the document is now reinstalled. —Preceding unsigned comment added by (talk) 17:57, 19 May 2009 (UTC)

Is there any need to retain the above ramble about a defunct broadcasting company that never went on the air and disappeared at least three years ago? —Preceding unsigned comment added by (talk) 22:42, 23 December 2010 (UTC)
It looks to be pursuing someone's private agenda :) —Preceding unsigned comment added by (talk) 22:53, 23 December 2010 (UTC) have misunderstood the above clarification. It is not about the broadcasting company but refers to the crystal clear evaluation of the Crossed Field Antennas in Egypt done by one of the foremost companies in the industry. —Preceding unsigned comment added by (talk) 13:28, 3 January 2011 (UTC)
Specific unauthorized references containing misquoted views from an unfinished confidential document has no place in Wikipedia.
Please explain Can user with IP, who wrote the last statement above, explain what is meant by "Unauthorized references" and what is meant by "misquoted views”, views belonging to whom? What is meant by "unfinished document” and what is meant by “confidential” and in what way is it “confidential”? The same person has also made changes in another person's contribution to the discussion made in 2009. For what reason was that done? Is it ethical to do so?
To see ethics being called on to defend this product with its lamentable history is rather amusing . .
So you claim that this is such a dangerous invention that justifies a self-proclaimed anonymous judge to exercise censorship by changing what others have written in this discussion? — Preceding unsigned comment added by WallofBricks (talkcontribs) 23:56, 12 January 2011 (UTC)
No :) but thanks for the anonymous comment :) —Preceding unsigned comment added by (talk) 18:11, 14 January 2011 (UTC)

Misguided ideas[edit]

IP did this revision of the article at 17:32 on the 26th of December 2010: “The CFA used in the Silsden tests, with an overall height of 13 metres, was of similar height to a conventional antenna for the same frequency.”

Very unsatisfactory with people without any knowledge about the Crossed field antenna get meddling with the article.

IP spreads misconceptions with the wild claim that a 13 meter high structure tuned as a conventional antenna performs slightly better than an equivalent 1/4 wave vertical monopole as was measured in the West Yorkshire tests.

The standard 1/4 wave vertical antenna mast on that wavelength (200 metres or 1500 kHz) is 50 meters high with some one hundred and twenty 50 meter long copper wires buried radially around it to maintain a high level of efficiency. That is common knowledge and a very well established fact. It is incredible to state that the 13 meter structure tuned as a conventional antenna and without the ground radials can outperform a standard 1/4 wave vertical monopole. If that was a fact why has 1/4 wave high broadcasting mast been built for all this years? —Preceding unsigned comment added by (talk) 11:34, 7 January 2011 (UTC)

That is another misguided idea: It is incorrect to suggest that anyone would use a 50-metre high antenna at these frequencies when a simple umbrella radiator with a height of 10-15 metres is the usual solution, as already stated, at many BBC and commercial radio transmitters in the UK. That is a reason why there have been no orders for a CFA in the last 12 years from the broadcasting community, as stated in the article. Quarter-wave antennas are rare at the high end of the medium wave band because they are uneconomic, the comparison is spurious and the comment indicates a lack of knowledge of the subject. —Preceding unsigned comment added by (talk) 17:55, 7 January 2011 (UTC)

CFA Patent Date?[edit]

Someone has re-edited the article several times insisting that the CFA was patented in 1986. But according to the UK patent documentation the application was Feb.02, 1988; the UK patent was filed Jan.27, 1989 and the UK publication was Sep.20, 1989. The US patent is dated Oct.13, 1992.

Can someone explain the statement that the CFA was patented in 1986? —Preceding unsigned comment added by (talk) 13:33, 23 January 2011 (UTC)

Does it matter? the thing was patented well over 20 years ago and is no longer a viable product after its many commercial failures. —Preceding unsigned comment added by (talk) 17:15, 22 April 2011 (UTC)

Incorrect statement on a web site[edit]

Have to remove this part of the article as the named person has not issued that statement on any web site.

Incorrect. More details of the lost deposit of £300,000 paid by the Isle of Man International Broadcasting Company to Kabbary Antenna Technology in 2005 are given on the web [1]. — Preceding unsigned comment added by (talk) 21:21, 9 September 2012 (UTC)

Biased references[edit]

The last two references (i.e. the only ones that are positive about the CFA) are from a website (apparently designed in the 90's) that seemingly exists to promote CFA's. The reports are also hilarious. Not only are there misspellings, which may be excusable, but they have the bias that one would expect a perpetual motion machine report to have. The main tests seem to have been done by the company promoting CFA's. The indpendent tests, done by a company recommended by OFCOM, are noted, but they are apparently "wrong". There are the same kinds of excuses that perpetual motion people use ("it was set up wrong" or "they did the wrong measurement"). I find it rather interesting that they dont actually mention this in the summary of conclusions. I intend to remove these sources, and the parts of the article that are based on them. If someone can give a good reason to put them back, then I will happily do so. Benboy00 (talk) 16:03, 1 December 2013 (UTC)

  1. ^ [1]