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#1
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Hi all:
I've been thinking about making a vertically polarized Delta Loop for 40m. I've seen articles on the internet having the feed point at one of the lower corners of the triangle for vertical polorization, others having the feed point on one of the sides, 1/4 wl from the top. Does it make any difference if its sloping (within reason) or does it need to be perpendicular to the ground? Anyone here have any experience here? Thanks, Bob--KD8WU U of M GO BLUE!! GOD, GUNS, and GUTS PROTECT AMERICA |
#3
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Dave, KC1DI wrote:
"You would be better off mounting it in the Horizontal plan(e)...(at other than 40 m) Performance versus polarization depends on soil loss in the antenna area. Over poor earth, horizontal polarization is better for take-off angles above 35 degrees. Below 35 degrees, vertical polarization is a little better, but not much, maybe 2dB. Over good earth, vertical antennas work much better than they do over poor earth. For take-off angles below 30 degrees, the large loop in the vertical plane may be 10 dB better than a large horizontal loop. Antenna height tends to lower take-off angle. If you want expert testimony, see "ON4UN`s "Low-Band DXing" page 10-9. ARRL is the publisher. Best regards, Richard Harrison, KB5WZI |
#4
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I have had good luck with the superloop 40 from radioworks which is a
bottom fed vertical delta loop. Contrary to Cebik, I find that it's about 1/2 S unit better on 40M than my dipole, although the vertical section is a stub and makes it not exactly a delta loop on 40M.. fyi JR AA2T On 28 Feb 2004 21:42:38 GMT, am (Bob Colenso) wrote: Hi all: I've been thinking about making a vertically polarized Delta Loop for 40m. I've seen articles on the internet having the feed point at one of the lower corners of the triangle for vertical polorization, others having the feed point on one of the sides, 1/4 wl from the top. Does it make any difference if its sloping (within reason) or does it need to be perpendicular to the ground? Anyone here have any experience here? Thanks, Bob--KD8WU U of M GO BLUE!! GOD, GUNS, and GUTS PROTECT AMERICA |
#6
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Bob, KD8WU wrote:
"I`ve had good luck with the superloop 40 from radioworks which is a bottom fed vertical delta loop." I`m ignorant of the superloop 40 but am guessing it is a small multiturn loop for enhancing reception only. If so, the following applies. If the superloop 40 is a full wavelength in circumference, I`m all wet. "Delta loop" usually implies more than a triangular shape. It usually means a large loop, often an entire wavelength in circumference. When the circumference of a loop is a small fraction of a wavelength, current throughout a turn in the loop is nearly in the same phase and magnitude. This is responsible for a null in the loop`s response perpendicular to the plane of the loop. Loop response is in all the directions which are in the plane of the loop. Not so with the large loop, delta, quad, or circular. These large loops have a response perpendicular to the plane of the loop which allows loop elements to be stacked like the rods in a Yagi so that a cmbination called a "Quagi" can be built. A small loop with one or 40 turns is a different animal from a large loop. Best regards, Richard Harrison, KB5WZI |
#7
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All the theory is fine, but the bottom line on the superloop 80 or 40 in the
vertical plan is that they work and very well at that. Larry "Richard Harrison" wrote in message ... Bob, KD8WU wrote: "I`ve had good luck with the superloop 40 from radioworks which is a bottom fed vertical delta loop." I`m ignorant of the superloop 40 but am guessing it is a small multiturn loop for enhancing reception only. If so, the following applies. If the superloop 40 is a full wavelength in circumference, I`m all wet. "Delta loop" usually implies more than a triangular shape. It usually means a large loop, often an entire wavelength in circumference. When the circumference of a loop is a small fraction of a wavelength, current throughout a turn in the loop is nearly in the same phase and magnitude. This is responsible for a null in the loop`s response perpendicular to the plane of the loop. Loop response is in all the directions which are in the plane of the loop. Not so with the large loop, delta, quad, or circular. These large loops have a response perpendicular to the plane of the loop which allows loop elements to be stacked like the rods in a Yagi so that a cmbination called a "Quagi" can be built. A small loop with one or 40 turns is a different animal from a large loop. Best regards, Richard Harrison, KB5WZI |
#8
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#9
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KC1DI wrote:
Richard the Super loop is a full wave loop on the lowest operating frequency .. IE Super loop 40 is a full wave 40 Meter delta loop.. the difference is that it has a shorted stup opposet the fedpoint which present a high impedence on twice the fundamental frequecy which effectively opens the loop on bands above the fundamental so that it acts more like a Bi-Square antenna on twice the frequency of design. Dave, please turn on your spell checker. Does "stup opposet" mean "stub opposite"? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#10
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On Tue, 02 Mar 2004 13:59:29 -0600, Cecil Moore
wrote: KC1DI wrote: Richard the Super loop is a full wave loop on the lowest operating frequency .. IE Super loop 40 is a full wave 40 Meter delta loop.. the difference is that it has a shorted stup opposet the fedpoint which present a high impedence on twice the fundamental frequecy which effectively opens the loop on bands above the fundamental so that it acts more like a Bi-Square antenna on twice the frequency of design. Dave, please turn on your spell checker. Does "stup opposet" mean "stub opposite"? Thanks Cecil it does me stub ! not Stup Sorry. 73 Dave ... |
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