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Why does the Lazy H antenna suck in the real world on 11 meters?
I've seen the Lazy H mentioned in many antenna books over the years,
so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 11:42 am, Michael wrote:
I also make sure there is no twist in the ladder line connecting the top and bottom elements. I'd have to look at a diagram of the lazy H, but I think that is your problem. The elements need to be transposed. Which means you want a 1/2 twist in the connecting ladder line. IE: the bottom left should connect to the top right, and visa versa. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 1:16 pm, wrote:
On Jul 5, 11:42 am, Michael wrote: I also make sure there is no twist in the ladder line connecting the top and bottom elements. I'd have to look at a diagram of the lazy H, but I think that is your problem. The elements need to be transposed. Which means you want a 1/2 twist in the connecting ladder line. IE: the bottom left should connect to the top right, and visa versa. As I understand it you only twist the interconnecting ladder line if you are feeding the Lazy H antenna at the bottom (end fire), but if you are feeding it in the middle of the interconnecting 450 ladder line then you leave out the twist. At least that's what I'm gathering from the pictures I have found. One correction. I have a Dentron MT-3000a antenna tuners with a 4:1 balun and not the MT-2000. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On 5 jul, 18:42, Michael wrote:
I've seen the Lazy H mentioned in many antenna books over the years, so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael Hi Michael, Normally spoken the feedline between top to bottom elements is 0.5lambda long, without twist, feeding in the middle. The path from feedpoint to end of the radiation elements is 0.75 lambda, giving an almost real low input impedance (on order of 30 Ohms, depending on thickness of radiating elements). In fact you have two full wave dipoles fed in phase that give most radiation (ground ignored) perpendicular to the array (bidirectional). There is a vertical null Why choosing 5/8 lambda vertical element spacing? You create a vertical lobe and a null in the elevation radiation pattern under about 53 degrees. You also get a strong reactive input impedance, but this may not be a problem with the ladder line. Did you do some indicative field strength measurements (diode detector) to find out whether it (and the elements) do(es) radiate (comparing to the other antennas)? It may also reveal some hidden things. Maybe somebody knows a loss figure for your ladder line (at 28 MHz) to assess the losses in the line (200ft part) because of bad VSWR. Best regards, Wim PA3DJS www.tetech.nl When you remove abc, the mail does work. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 3:55 pm, Wimpie wrote:
On 5 jul, 18:42, Michael wrote: I've seen the Lazy H mentioned in many antenna books over the years, so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael Hi Michael, Normally spoken the feedline between top to bottom elements is 0.5lambda long, without twist, feeding in the middle. The path from feedpoint to end of the radiation elements is 0.75 lambda, giving an almost real low input impedance (on order of 30 Ohms, depending on thickness of radiating elements). In fact you have two full wave dipoles fed in phase that give most radiation (ground ignored) perpendicular to the array (bidirectional). There is a vertical null Why choosing 5/8 lambda vertical element spacing? You create a vertical lobe and a null in the elevation radiation pattern under about 53 degrees. You also get a strong reactive input impedance, but this may not be a problem with the ladder line. Did you do some indicative field strength measurements (diode detector) to find out whether it (and the elements) do(es) radiate (comparing to the other antennas)? It may also reveal some hidden things. Maybe somebody knows a loss figure for your ladder line (at 28 MHz) to assess the losses in the line (200ft part) because of bad VSWR. Best regards, Wim PA3DJSwww.tetech.nl When you remove abc, the mail does work. Hi Wim, According to the ARRL handbook the highest gain is achieve with a 5/8ths wave spacing between the upper and lower elements. The handbook gives the following figures for estimated gain. 3/8 wave spacing = 4.4 dbd 1/2 wave spacing = 5.9 dbd 5/8 wave spacing = 6.7 dbd 3/4 wave spacing = 6.6 dbd EZNEC shows a similar gain peak with a 5/8th wave spacing between the top and bottom elements. It seems to works on 14 MHz (stacked dipoles at 14 MHz), but on 10 meters the single 10 meter dipole blows it away. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 5:32 pm, Michael wrote:
On Jul 5, 3:55 pm, Wimpie wrote: On 5 jul, 18:42, Michael wrote: I've seen the Lazy H mentioned in many antenna books over the years, so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael Hi Michael, Normally spoken the feedline between top to bottom elements is 0.5lambda long, without twist, feeding in the middle. The path from feedpoint to end of the radiation elements is 0.75 lambda, giving an almost real low input impedance (on order of 30 Ohms, depending on thickness of radiating elements). In fact you have two full wave dipoles fed in phase that give most radiation (ground ignored) perpendicular to the array (bidirectional). There is a vertical null Why choosing 5/8 lambda vertical element spacing? You create a vertical lobe and a null in the elevation radiation pattern under about 53 degrees. You also get a strong reactive input impedance, but this may not be a problem with the ladder line. Did you do some indicative field strength measurements (diode detector) to find out whether it (and the elements) do(es) radiate (comparing to the other antennas)? It may also reveal some hidden things. Maybe somebody knows a loss figure for your ladder line (at 28 MHz) to assess the losses in the line (200ft part) because of bad VSWR. Best regards, Wim PA3DJSwww.tetech.nl When you remove abc, the mail does work. Hi Wim, According to the ARRL handbook the highest gain is achieve with a 5/8ths wave spacing between the upper and lower elements. The handbook gives the following figures for estimated gain. 3/8 wave spacing = 4.4 dbd 1/2 wave spacing = 5.9 dbd 5/8 wave spacing = 6.7 dbd 3/4 wave spacing = 6.6 dbd EZNEC shows a similar gain peak with a 5/8th wave spacing between the top and bottom elements. It seems to works on 14 MHz (stacked dipoles at 14 MHz), but on 10 meters the single 10 meter dipole blows it away. Well I tried reducing the spacing between the top and bottom elements to 1/2 wave spacing, but it still did not seem to make any difference. I've noticed in the past when working with ladder line that tuning an antenna with an antenna tuner from about 14 MHz and down brings up the receive verses by-passing the tuner completely, but that never seems to happen once you reach 10 meters. I wonder if that has something to do with it. |
Why does the Lazy H antenna suck in the real world on 11 meters?
I'm not sure, but if the Lazy H has Horizontal polarity and the folks you're
trying to communicate with are using Verticals, there may be quite a bit of signal loss. Since you mentioned it was for 11 meters, can we assume you're trying to communicate without using 'skip'? |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 10:44 pm, "Hal Rosser" wrote:
I'm not sure, but if the Lazy H has Horizontal polarity and the folks you're trying to communicate with are using Verticals, there may be quite a bit of signal loss. Since you mentioned it was for 11 meters, can we assume you're trying to communicate without using 'skip'? It meant for skip. I mean to type 10 meters. Old habits die hard as I started on the CB band. .. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 10:44 pm, "Hal Rosser" wrote:
I'm not sure, but if the Lazy H has Horizontal polarity and the folks you're trying to communicate with are using Verticals, there may be quite a bit of signal loss. Since you mentioned it was for 11 meters, can we assume you're trying to communicate without using 'skip'? It is meant for skip. I typed 10 meters at the start of the message, but 11 meters in the Subject line. Old habits die hard as I started on the CB band. |
Why does the Lazy H antenna suck in the real world on 11 meters?
Michael wrote:
On Jul 5, 10:44 pm, "Hal Rosser" wrote: I'm not sure, but if the Lazy H has Horizontal polarity and the folks you're trying to communicate with are using Verticals, there may be quite a bit of signal loss. Since you mentioned it was for 11 meters, can we assume you're trying to communicate without using 'skip'? It meant for skip. I mean to type 10 meters. Old habits die hard as I started on the CB band. . In my area, San Joaquin Valley, Ca--most 10m is on verticals ... while the guys running the "one size fits all" antennas--or, 80-10m (or, even 160-10m!) are mostly horiz--since a 10m is so easy, they slap up a 10m vertical also. The "myth" that most noise is vertically polarized--well, I never subscribed to that (but, when I was a kid, I first believed it!) Most runs off above ground power-lines are even, somewhere, around a 45 degree angle (and, above ground power-lines are ALWAYS horiz polarized! Drive around and look, maybe they do it different in your area ... ??? And, now, most power-lines have went under-ground in my area ... vertical is fine with me and I don't send my signal skyward or into the ground, where it may reflect into the stratosphere anyway ... Regards, JS |
Why does the Lazy H antenna suck in the real world on 11 meters?
Michael wrote:
According to the ARRL handbook the highest gain is achieve with a 5/8ths wave spacing between the upper and lower elements. The handbook gives the following figures for estimated gain. 3/8 wave spacing = 4.4 dbd 1/2 wave spacing = 5.9 dbd 5/8 wave spacing = 6.7 dbd 3/4 wave spacing = 6.6 dbd It seems to works on 14 MHz (stacked dipoles at 14 MHz), but on 10 meters the single 10 meter dipole blows it away. Quoting the ARRL Antenna Book: "It should be designed for the higher of the two frequencies using 3/4 lamda spacing between parallel elements. It will then operate on the lower frequency ... with 3/8 lamda spacing. If you have 5/8 lamda spacing on 20m, you will have 5/4 lamda spacing on 10m with poor performance. -- 73, Cecil http://www.w5dxp.com |
Why does the Lazy H antenna suck in the real world on 11 meters?
John Smith wrote:
Michael wrote: On Jul 5, 10:44 pm, "Hal Rosser" wrote: I'm not sure, but if the Lazy H has Horizontal polarity and the folks you're trying to communicate with are using Verticals, there may be quite a bit of signal loss. Since you mentioned it was for 11 meters, can we assume you're trying to communicate without using 'skip'? It meant for skip. I mean to type 10 meters. Old habits die hard as I started on the CB band. . In my area, San Joaquin Valley, Ca--most 10m is on verticals ... while the guys running the "one size fits all" antennas--or, 80-10m (or, even 160-10m!) are mostly horiz--since a 10m is so easy, they slap up a 10m vertical also. The "myth" that most noise is vertically polarized--well, I never subscribed to that (but, when I was a kid, I first believed it!) Most runs off above ground power-lines are even, somewhere, around a 45 degree angle (and, above ground power-lines are ALWAYS horiz polarized! Drive around and look, maybe they do it different in your area ... ??? And, now, most power-lines have went under-ground in my area ... vertical is fine with me and I don't send my signal skyward or into the ground, where it may reflect into the stratosphere anyway ... Regards, JS And, I almost forgot, ever attempt to get a horiz 20m+ ant on a mobile? (I haven't!) Regards, JS |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 11:04 pm, Cecil Moore wrote:
Michael wrote: According to the ARRL handbook the highest gain is achieve with a 5/8ths wave spacing between the upper and lower elements. The handbook gives the following figures for estimated gain. 3/8 wave spacing = 4.4 dbd 1/2 wave spacing = 5.9 dbd 5/8 wave spacing = 6.7 dbd 3/4 wave spacing = 6.6 dbd It seems to works on 14 MHz (stacked dipoles at 14 MHz), but on 10 meters the single 10 meter dipole blows it away. Quoting the ARRL Antenna Book: "It should be designed for the higher of the two frequencies using 3/4 lamda spacing between parallel elements. It will then operate on the lower frequency ... with 3/8 lamda spacing. If you have 5/8 lamda spacing on 20m, you will have 5/4 lamda spacing on 10m with poor performance. -- 73, Cecil http://www.w5dxp.com Not only that, but will depend if feeding end fire, or broadside. It's only as a broadside array that max gain is at 5/8 wl spacing. And he is feeding his as an end fire array. The elements would need to be end to end IE: collinear, array to be fed as a broadside array. As an end fire, the spacing must be quite a bit closer. If I remember right, max gain with an end fire array is appx 1/8 wl spacing. But from my own experimenting around with them, it's not ultra critical as far as getting them to work. In my case, I was feeding each element with a separate feed line, and changing lengths to steer the array. It was quite crude, but worked pretty well. In my case, I tried to compromise on the spacing so I could feed it both end fire, and broadside. I think I used about 1/4 wl. I also used about the same scheme on 10m, using two 5/8 wl ground planes. I forgot the exact spacing I used. It was more dictated by available mast/.vent pipe locations more than trying to get an exact length. But it was a compromise spacing, and I fed it both ways depending on the pattern I wanted. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 6, 12:59 am, wrote:
But it was a compromise spacing, and I fed it both ways depending on the pattern I wanted. Just thinking about another thing.. I think feeding in phase would give a bi directional pattern, but if he wanted an omni directional pattern, I think he'd have to have the elements 90 degrees out of phase. But I fergot... He could fire up eznec demo or whatever and he can quickly get a pretty good idea what to expect in theory with any particular spacing and phasing. He could crudely steer the pattern if he used various length feeders to each element. Some also use the "L/C" phasing boxes to steer the pattern. Again fairly crude compared to some methods, but it will work. Just don't expect perfect textbook patterns. You have to take what you get... The ARRL antenna book has better methods if want cleaner patterns. |
Why does the Lazy H antenna suck in the real world on 11 meters?
|
Why does the Lazy H antenna suck in the real world on 11 meters?
John Smith wrote:
Or, if you don't wish the built-in limitations of Eznec (the demo version), try MMANA GAL. Will feed the same data to the nec engine(s.) Regards, JS Forgot, should have given a URL to go with that: http://mmhamsoft.amateur-radio.ca/mmana/index.htm Regards, JS |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 6, 1:16 am, wrote:
Ya know what, I guess he is running as a broadside array after all.. I was thinking he had the elements horizontal, but after rereading the first post, he does have them stacked. And if they were in phase, that should be a broadside array. Sooo... I finally decided to check it in the program using two 1/2 wave elements for 10m, with the lower element at 1/2 wave up, "16 ft", and the upper one at appx 5/8 wave higher. "37 ft" Using the single lower element alone, I got 2.08 dbi. Using both in phase, I got 6.8 dbi.. So, it should work as planned.. Not sure what the problem would be though, unless you have coupling problems with other metal in the area, etc.. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On 6 jul, 05:01, Michael wrote:
On Jul 5, 10:44 pm, "Hal Rosser" wrote: I'm not sure, but if the Lazy H has Horizontal polarity and the folks you're trying to communicate with are using Verticals, there may be quite a bit of signal loss. Since you mentioned it was for 11 meters, can we assume you're trying to communicate without using 'skip'? It is meant for skip. I typed 10 meters at the start of the message, but 11 meters in the Subject line. Old habits die hard as I started on the CB band. Hello Michael, You mentioned that even your hor. dipole blows away the Lazy H (also for good orientation). This rules out every influence because of minimum elevation angle of main beam versus ground conductivity/ permittivity. I assume that you are talking about several S-points. There must be something really wrong. The dipole close to ground will have some different impedance (then the upper). This will cause some phase error, but this should not lead to a drastic reduction of overall gain. According to your postings, the construction is OK (no twist, feeding in the middle). I also assume that you have some spacing between the 5/8 lambda long vertical line and the actual feed line (of 200ft), to avoid coupling between the two. It can be the line, or the tuner/balun. Line Losses increase and when your VSWR in the line is very high, this may increase the overall loss in your 450 Ohm feed line. If possible compare the field strength of your hor. dipole with field strength of the lazy H. Other option is to find an unused frequency en put in lots of power and look for temperature increase. Best regards, Wim PA3DJS www.tetech.nl The mail does function when you remove abc |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 6, 12:04 am, Cecil Moore wrote:
Michael wrote: According to the ARRL handbook the highest gain is achieve with a 5/8ths wave spacing between the upper and lower elements. The handbook gives the following figures for estimated gain. 3/8 wave spacing = 4.4 dbd 1/2 wave spacing = 5.9 dbd 5/8 wave spacing = 6.7 dbd 3/4 wave spacing = 6.6 dbd It seems to works on 14 MHz (stacked dipoles at 14 MHz), but on 10 meters the single 10 meter dipole blows it away. Quoting the ARRL Antenna Book: "It should be designed for the higher of the two frequencies using 3/4 lamda spacing between parallel elements. It will then operate on the lower frequency ... with 3/8 lamda spacing. If you have 5/8 lamda spacing on 20m, you will have 5/4 lamda spacing on 10m with poor performance. -- 73, Cecil http://www.w5dxp.com It is designed for the higher band. |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 5, 12:42 pm, Michael wrote:
I've seen the Lazy H mentioned in many antenna books over the years, so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael I found an article that shows using a 1/4 wave matching stub at the bottom of an end fire Lazy H with 1/2 wave spacing. Perhaps even ladder line transmission line needs a matching stub. http://www.ve7zsa.net/technical/advs...ntenna_r00.htm |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 6, 1:55 pm, Michael wrote:
On Jul 5, 12:42 pm, Michael wrote: I've seen the Lazy H mentioned in many antenna books over the years, so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael I found an article that shows using a 1/4 wave matching stub at the bottom of an end fire Lazy H with 1/2 wave spacing. Perhaps even ladder line transmission line needs a matching stub. http://www.ve7zsa.net/technical/advs...ntenna_r00.htm Looks like another user had similar problems with a Lazy H using 450 ladder line all the way to the tuner. Like me his will tune on 14 MHz where it is basically stacked dipoles, but once you get to 10 meters it is a no go. He tried 450 ohm ladder line to a balun as well. http://forums.qrz.com/archive/index.php/t-135914.html |
Why does the Lazy H antenna suck in the real world on 11 meters?
On Jul 6, 1:55 pm, Michael wrote:
On Jul 5, 12:42 pm, Michael wrote: I've seen the Lazy H mentioned in many antenna books over the years, so I decided to try one on 10 meters. According to the ARRL handbook the Lazy H is two collinear elements stacked on above the other, Each collinear element is made up of two 1/2 wave elements. I chose to use 5/8 wave spacing between the top and bottom elements. I connected the top and bottom elements with 450 ohm 16 gauge stranded ladder line (window line). After building the antenna I verified connectivity between the top and bottom right elements and the top and bottom left elements. I color coded the end insulators on each side so I could easily see which top and bottom elements were connected to each other. The antenna book says to connect the 450 ohm ladder line from the antenna tuner to the middle of the 450 ladder line that connects top and bottom elements. Ok done. Now I put up the antenna and make sure the top and bottom elements are in phase. That is both left connected elements are on the left and both right connected element are on the right. I also make sure there is no twist in the ladder line connecting the top and bottom elements. I also checked the other ends of the 450 ohm ladder line feeding the antenna has connectivity at the antenna, and the left and right sides of the ladder line do not have connectivity. The 450 ohm ladder line feeding the antenna is about 200 feet long. Now I bring the 450 ohm feedline in to the house, hook it to my Dentron MT-2000 antenna tuner with the 4:1 balun inside, tune it up, and it sucks! Both my half wave horizontal dipole and my Solarcon Max-2000 blow it away on incoming skip even in the preferred direction of the lazy H. I rechecked my connections and the lengths of the elements and spacing and they are correct. I did take in to account the velocity factor of the 450 ladder line that connects the top elements to the bottom elements. The antenna book says the length of the 450 ladder lien between the antenna and the antenna tuner can e any lenght. The bottom element is at least 1/2 wave of the ground, and the top element is 5/8ths wave above that. What did I do wrong? Michael I found an article that shows using a 1/4 wave matching stub at the bottom of an end fire Lazy H with 1/2 wave spacing. Perhaps even ladder line transmission line needs a matching stub. http://www.ve7zsa.net/technical/advs...ntenna_r00.htm Yep. Looks like that is it. Unfortunately I am out of time for this weekend, so I'll have to try it out next weekend. According to an article I found I need a closed end 1/4 matching stub. I'll update here after I try it out next weekend. -Michael |
Why does the Lazy H antenna suck in the real world on 11 meters?
The bottom element is at least 1/2 wave of the ground, and the top
element is 5/8ths wave above that. What did I do wrong? I suspect with your long feedline length (200 ft you said?), and the probably very high SWR on the feedline, you have significant feedline loss. Also, are the elements really horizontal? Or are they closer to inverted V's? Tor N4OGW |
Why does the Lazy H antenna suck in the real world on 11 meters?
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