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#1
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Stefan Bürbaum wrote:
In a antenna lexicon I found something about a cloverleaf antenna from Phillip H. Smith. I found only Pics from this type in use (or out of order) for BC stations. I'm not aware of any vertical antennas with cloverleaf patterns so I am going to assume it is a horizontal antenna (as used for BC shortwave). A horizontal dipole longer than 1.25WL tends to have a multi-lobed radiation pattern, at one point, resembling a cloverleaf. Such a pattern is pretty much four-lobed when the dipole is about 1.6WL. At shorter wavelengths than that, it exhibits more than four lobes and at high multiples of the 1/2WL resonant frequency, becomes essentially an end-fire antenna. -- 73, Cecil, W5DXP |
#2
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Stefan Burbaum wrote:
"Can anyone tell me more about this type?" John D. Kraus, W8JK says about the Cloverleaf Antenna for FM Broadcasting on page 429 of his 1950 edition of "Antennas": "One method of simulating the uniform loop is illustrated in Fig. 14-38b. Here four smaller loops are connected in parallel across a coaxial line. This arrangement is called a "cloverleaf" antenna. (P.H. Smith, Cloverleaf Antenna for FM Broadcasting, Proc. I.R.E.,35, 1556-1563, December 1947)." Best regards, Richard Harrison, KB5WZI |
#3
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Kraus retained his "Cloverleaf Antenna" story in his new 3rd edition. It
is found on page 726. Almost identical to the 1950 story. Best regards, Richard Harrison, KB5WZI |
#4
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Richard Harrison wrote:
Kraus retained his "Cloverleaf Antenna" story in his new 3rd edition. It is found on page 726. Almost identical to the 1950 story. Darn, I should have looked in the index of my Kraus book before I replied in ignorance. -- 73, Cecil, W5DXP |
#5
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"Cecil Moore" wrote in message
... Stefan Bürbaum wrote: In a antenna lexicon I found something about a cloverleaf antenna from Phillip H. Smith. I found only Pics from this type in use (or out of order) for BC stations. I've made and used a cloverleaf antenna for 2m in a RSGB 2m Trophy contest. Used two of them stacked for extra gain. Results were very good and allowed up complete coverage of the UK. |
#6
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Cecil Moore wrote:
Stefan Bürbaum wrote: In a antenna lexicon I found something about a cloverleaf antenna from Phillip H. Smith. I found only Pics from this type in use (or out of order) for BC stations. I'm not aware of any vertical antennas with cloverleaf patterns so I am going to assume it is a horizontal antenna (as used for BC shortwave). A horizontal dipole longer than 1.25WL tends to have a multi-lobed radiation pattern, at one point, resembling a cloverleaf. Such a pattern is pretty much four-lobed when the dipole is about 1.6WL. At shorter wavelengths than that, it exhibits more than four lobes and at high multiples of the 1/2WL resonant frequency, becomes essentially an end-fire antenna. -- 73, Cecil, W5DXP I Remember back in early 60's a number of hams in my home town built clover leaf antennas for 2 & 6 meters.. if my memory serves me right they were horizontally mounted and worked quite well for 2 & 6 Mtr AM in those days .. I used one as a novice for 2 mtrs. Novices had 2m AM priviledges back then. But I had nothing to compare it to so can't say it was better or worse tnan any other 2m antenna. Also if memory serves me right it was mad up of 3 heart shaped full wave loops condected in paralell and fed with a single coaxial line. 73 Dave Kc1di ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#7
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![]() "KC1DI" wrote in message ... Cecil Moore wrote: Stefan Bürbaum wrote: -- SNIP-- I Remember back in early 60's a number of hams in my home town built clover leaf antennas for 2 & 6 meters.. if my memory serves me right they were horizontally mounted and worked quite well for 2 & 6 Mtr AM in those days .. I used one as a novice for 2 mtrs. Novices had 2m AM priviledges back then. But I had nothing to compare it to so can't say it was better or worse tnan any other 2m antenna. Also if memory serves me right it was mad up of 3 heart shaped full wave loops condected in paralell and fed with a single coaxial line. 73 Dave Kc1di I still have such an antenna -- for two meters. It is the Cuschcraft Big Wheel. It consists of 3 vertex-rounded triangular elements. I think they are a full wavelength with one side of each connected to the center conductor of the coax and the other side of each connected to ground. So it looks like a cloverleaf. It produces an omni-directional pattern. My antenna has four of these stacked with phasing harnesses. The original inquiry mentioned for use at broadcast frequencies, so I doubt that the Big Wheel is what is meant. Ed, N5EI |
#8
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Richard Harrison wrote:
"Can anyone tell me more about this type?" John D. Kraus, W8JK says about the Cloverleaf Antenna for FM Broadcasting on page 429 of his 1950 edition of "Antennas": "One method of simulating the uniform loop is illustrated in Fig. 14-38b. Here four smaller loops are connected in parallel across a coaxial line. This arrangement is called a "cloverleaf" antenna. (P.H. Smith, Cloverleaf Antenna for FM Broadcasting, Proc. I.R.E.,35, 1556-1563, December 1947)." Thank you. Is this old book the only with a description of this antenna? I found a pic from the WNEX Antenna: http://www.theinternetfarm.com/goodt.../wnexhist5.htm Is there a scan from the pic in the book in the net? Its very old, it should be free? Why is this type of antenna not in use? I know, the Big Wheel is a very good construction and very popular. What was the advantage of Smith's cloverleaf antenna? Stefan B=FCrbaum, OE3SBA |
#9
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Stefan Burbaum wrote:
"Is this old book the only with a description of this antenna?" No. The new 3rd edition of "Antennas" also has the "clover-leaf" on page 726 along with several similar types. I`ll speculate that the horizontally polarized omnidirectional antenna has faded in popularity due to so many automobile FM radios in use. Vertical or circular polarization may be better for line-of-sight propagation to an automobile which is equipped with a vertical car antenna. Best regards, Richard Harrison, KB5WZI |
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