Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
Hello everybody,
I hope everyone had a very Happy Easter. I have a spare 2:1 current balun and would like to use it to feed a vertically oriented single- band full-wave loop. I began to wonder; Can one feed two vertically oriented full-wave loops perpendicular to each other with a common feed point? Any opinions? Thanks in advance. As always, take care es... Vy 73 de Bert WA2SI |
#2
![]() |
|||
|
|||
![]()
Can one feed two vertically oriented full-wave loops perpendicular to each other with a common feed point?
Many have. 73's Richard Clark, KB7QHC |
#3
![]() |
|||
|
|||
![]()
On 7 abr, 01:47, WA2SI wrote:
Hello everybody, I hope everyone had a very Happy Easter. I have a spare 2:1 current balun and would like to use it to feed a vertically oriented single- band full-wave loop. I began to wonder; Can one feed two vertically oriented full-wave loops perpendicular to each other with a common feed point? Any opinions? Thanks in advance. As always, take care es... Vy 73 de Bert WA2SI Hello Bert, When you have identical loops, with same orientation, and distance between them is less then 0.2 lambda, you can connect them in parallel. Current in both loops will be the same (magnitude and phase) and far field radiation pattern will also not change (with respect to a single loop). When the distance between the loops wire diameter, you will experience an increase in useful bandwidth. Impedance at current nodes will not change that much, but impedance at voltage nodes will reduce. Due to the mutual coupling, you will experience some drift in resonant frequency. Feeding in opposite phase will give a complete new radiation pattern, significant reduction in useful bandwidth and possibly reduction in radiation efficiency. Best regards, Wim PA3DJS www.tetech.nl in case of PM, don't forget to remove abc from the address. |
#4
![]() |
|||
|
|||
![]()
Wonderful!
Last edited by Libra : June 1st 10 at 10:30 PM Reason: Politeness. |
#5
![]() |
|||
|
|||
![]()
On Apr 6, 6:47*pm, WA2SI wrote:
Hello everybody, I hope everyone had a very Happy Easter. I have a spare 2:1 current balun and would like to use it to feed a vertically oriented single- band full-wave loop. I began to wonder; Can one feed two vertically oriented full-wave loops perpendicular to each other with a common feed point? Any opinions? Thanks in advance. As always, take care es... Vy 73 de Bert WA2SI I am taking your question as, 2 vertical loops, both hung from the same skyhook, one broadside north/south, and the other broadside east/west, and fed at the same point. You get a more omni radiation pattern, but not full omni, there are still lobes. This is much like 2 crossed dipoles (for the same band) in an "X" configuration. Depending on height, you may not need the 2:1 balun. Check your impedance, a coax wound balun for a choke may be all that is necessary. 73....Walter - K5EST |
#6
![]() |
|||
|
|||
![]()
On Tue, 13 Apr 2010 09:59:08 -0700 (PDT), JIMMIE
wrote: Ive never seen them connected in parallel We have talked about them at length here. What was described is a quadrifilar helix - without the helix. As there are so many details of construction are missing, little more can be said, and our original poster appears to have gotten bored with the topic. 73's Richard Clark, KB7QHC |
#7
![]() |
|||
|
|||
![]()
On Tue, 13 Apr 2010 11:23:00 -0700 (PDT), Wimpie
wrote: When you put them 90 degr. to each other (for example E/W and one N/ S), you will not get an omni-pattern. In that case you must make them both off-resonance to get 90 degr phase time shift in generated fields (or use a 90 degr. phase shifter and feed them separately). Hi Wim, You can do it with a goniometer. This antenna was first described 103 years ago by Bellini and Tosi. 73's Richard Clark, KB7QHC |
#8
![]() |
|||
|
|||
![]()
On Apr 13, 1:36*pm, Richard Clark wrote:
As there are so many details of construction are missing, little more can be said, and our original poster appears to have gotten bored with the topic. 73's Richard Clark, KB7QHC Hello agn, everybody: My apologies to you all. No, I have not gotten bored with this topic. My job has rotating schedules as well as mandatory overtime. Unfortunately, when one gets "stuck" for o/t, it's usually for an entire extra 8-1/2 tour. When I finally get home, (A nice hike, btw!) I either attend to my familial obligations or just crash. I did manage to work a 5R8 station on the bottom of 80 so all was not lost - hihi. I was thinking of making use of some unused space on my 50' fiberglass mast by mounting a 2:1 balun and having two 10m vertically polarized delta loops sharing the same feed points, specifically the aforementioned balun. Yes, the goal is a single band, quiet and physically unobtrusive single-band omni-directional. (Or at least somewhat omni-directional without being a cloudburner.) Visualize, if you will, two wire Christmas tree shaped wire loops, 90 degrees from one another, fed at the center of their bottom legs up abt 30'. Some might say, "why not just mount a vertical?" Well, I have the 2:1 balun and I figured that the loop would be much quieter. Thanks so much for all your responses and have a safe and wonderful weekend. Take care es... Vy 73 de Bert, WA2SI |
#9
![]() |
|||
|
|||
![]()
On Apr 17, 8:06*am, WA2SI wrote:
On Apr 13, 1:36*pm, Richard Clark wrote: As there are so many details of construction are missing, little more can be said, and our original poster appears to have gotten bored with the topic. 73's Richard Clark, KB7QHC Hello agn, everybody: My apologies to you all. No, I have not gotten bored with this topic. My job has rotating schedules as well as mandatory overtime. Unfortunately, when one gets "stuck" for o/t, it's usually for an entire extra 8-1/2 tour. When I finally get home, (A nice hike, btw!) I either attend to my familial obligations or just crash. I did manage to work a 5R8 station on the bottom of 80 so all was not lost - hihi. I was thinking of making use of some unused space on my 50' fiberglass mast by mounting a 2:1 balun and having two 10m vertically polarized delta loops sharing the same feed points, specifically the aforementioned balun. Yes, the goal is a single band, quiet and physically unobtrusive single-band omni-directional. (Or at least somewhat omni-directional without being a cloudburner.) Visualize, if you will, two wire Christmas tree shaped wire loops, 90 degrees from one another, fed at the center of their bottom legs up abt 30'. Some might say, "why not just mount a vertical?" Well, I have the 2:1 balun and I figured that the loop would be much quieter. Thanks so much for all your responses and have a safe and wonderful weekend. Take care es... Vy 73 de Bert, WA2SI I ran a single loop like you are talking about on 10M and had to use a 75 ohm 1/4 wl transformer to match the approximately 100 ohm impedance of the loop. I would think the two antennas mounted at right angles to each other should be a pretty good match for 50 ohms. Jimmie |
#10
![]() |
|||
|
|||
![]()
On Apr 17, 8:06*am, WA2SI wrote:
On Apr 13, 1:36*pm, Richard Clark wrote: As there are so many details of construction are missing, little more can be said, and our original poster appears to have gotten bored with the topic. 73's Richard Clark, KB7QHC Hello agn, everybody: My apologies to you all. No, I have not gotten bored with this topic. My job has rotating schedules as well as mandatory overtime. Unfortunately, when one gets "stuck" for o/t, it's usually for an entire extra 8-1/2 tour. When I finally get home, (A nice hike, btw!) I either attend to my familial obligations or just crash. I did manage to work a 5R8 station on the bottom of 80 so all was not lost - hihi. I was thinking of making use of some unused space on my 50' fiberglass mast by mounting a 2:1 balun and having two 10m vertically polarized delta loops sharing the same feed points, specifically the aforementioned balun. Yes, the goal is a single band, quiet and physically unobtrusive single-band omni-directional. (Or at least somewhat omni-directional without being a cloudburner.) Visualize, if you will, two wire Christmas tree shaped wire loops, 90 degrees from one another, fed at the center of their bottom legs up abt 30'. Some might say, "why not just mount a vertical?" Well, I have the 2:1 balun and I figured that the loop would be much quieter. Thanks so much for all your responses and have a safe and wonderful weekend. Take care es... Vy 73 de Bert, WA2SI I ran a single loop like you are talking about on 10M and had to use a 75 ohm 1/4 wl transformer to match the approximately 100 ohm impedance of the loop. I would think the two antennas mounted at right angles to each other should be a pretty good match for 50 ohms. Jimmie |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Full-wave coaxial loop? | Antenna | |||
"Fan" Full Wave Loops? | Antenna | |||
Full Wave Loop Question | Antenna | |||
Full wave loops - alternate design? | Shortwave | |||
Question about Full Wave loop | Antenna |