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The Lazy H does not seem to exhibit any gain over a dipole in thereal world
Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. I made sure there was no twist in the ladder line connecting the top and bottom elements. I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY |
The Lazy H does not seem to exhibit any gain over a dipole in the real world
Michael Inscribed thus:
Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. I made sure there was no twist in the ladder line connecting the top and bottom elements. I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: Baron. |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 30, 2:44*pm, Baron wrote:
Michael Inscribed thus: * Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. *I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. *A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. * I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. *I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. *I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. *I made sure there was no twist in the ladder line connecting the top and bottom elements. * I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. *A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. * Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. *Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. *The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: * * * * * * * * * * * * * Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180°, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
Thanks for your input Walt, but I already thought of those things.
I definitely made the antenna correctly. According to the ARRL handbook when center feeding the Lazy H increasing the spacing beyond 1/2 wave makes the gain go up until the spacing reaches 5/8ths wave. The handbooks states 5.9 dbd gain for 1/2 wave spacing and 6.7 dbd for 5/8ths wave spacing. In the real world this antenna does not have any gain over a 1/2 wave dipole when center fed with 450 ohm ladder line all the way back to the tuner. The phasing was correct. On 14 MHz where it becomes two stacked dipoles the SWR comes down and the performance goes up, but on 28 MHz it consistently lags behind a dipole. I rebuilt this antenna twice. If you actually go to the trouble of making one for 10 meters, and compare it to a real world 28 Mhz 1/2 wave dipole, the Lazy H will fall far short of the predicted gain. I have been a ham since 1986. I wondered why I had heard so few hams using a Lazy H, and the one time I recalled hearing one the signal was weaker than the other hams using a dipole. I assumed at the time that I must have been off the side of the other ham's Lazy H, but after my real world test who knows. I'm going to remove the center feed from the antenna this week, and rework the Lazy H for end feed with a twist, a matching stub, and 1/2 wave spacing. Hopefully the end fed version of the Lazy H will live up to it's text book gain. I'd really like to have that 6 dbd gain along with the nulls off the sides, Michael Rawls KS4HY On May 30, 5:48*pm, walt wrote: On May 30, 2:44*pm, Baron wrote: Michael Inscribed thus: * Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. *I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. *A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. * I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. *I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. *I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. *I made sure there was no twist in the ladder line connecting the top and bottom elements. * I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. *A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. * Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. *Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. *The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: * * * * * * * * * * * * * Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180°, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 30, 9:31*pm, Michael wrote:
* Thanks for your input Walt, but I already thought of those things. I definitely made the antenna correctly. *According to the ARRL handbook when center feeding the Lazy H increasing the spacing beyond 1/2 wave makes the gain go up until the spacing reaches 5/8ths wave. The handbooks states 5.9 dbd gain for 1/2 wave spacing and 6.7 dbd for 5/8ths wave spacing. *In the real world this antenna does not have any gain over a 1/2 wave dipole when center fed with 450 ohm ladder line all the way back to the tuner. *The phasing was correct. On 14 MHz where it becomes two stacked dipoles the SWR comes down and the performance goes up, but on 28 MHz it consistently lags behind a dipole. *I rebuilt this antenna twice. *If you actually go to the trouble of making one for 10 meters, and compare it to a real world 28 Mhz 1/2 wave dipole, the Lazy H will fall far short of the predicted gain. * I have been a ham since 1986. *I wondered why I had heard so few hams using a Lazy H, and the one time I recalled hearing one the signal was weaker than the other hams using a dipole. *I assumed at the time that I must have been off the side of the other ham's Lazy H, but after my real world test who knows. * I'm going to remove the center feed from the antenna this week, and rework the Lazy H for end feed with a twist, a matching stub, and 1/2 wave spacing. *Hopefully the end fed version of the Lazy H will live up to it's text book gain. *I'd really like to have that 6 dbd gain along with the nulls off the sides, Michael Rawls KS4HY On May 30, 5:48*pm, walt wrote: On May 30, 2:44*pm, Baron wrote: Michael Inscribed thus: * Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. *I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. *A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. * I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. *I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. *I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. *I made sure there was no twist in the ladder line connecting the top and bottom elements. * I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. *A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. * Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. *Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. *The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: * * * * * * * * * * * * * Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180°, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU One other thought, Michael, is that if you made the lazy-H with 1/2wl spacing for 20m and then use it on 10m, the spacing is now 1wl. I haven't seen any figures for that spacing, but isn't it possible that with that spacing the gain might not be what you expect? Especially if it works properly on 20m? Walt |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 30, 10:37*pm, walt wrote:
On May 30, 9:31*pm, Michael wrote: * Thanks for your input Walt, but I already thought of those things. I definitely made the antenna correctly. *According to the ARRL handbook when center feeding the Lazy H increasing the spacing beyond 1/2 wave makes the gain go up until the spacing reaches 5/8ths wave. The handbooks states 5.9 dbd gain for 1/2 wave spacing and 6.7 dbd for 5/8ths wave spacing. *In the real world this antenna does not have any gain over a 1/2 wave dipole when center fed with 450 ohm ladder line all the way back to the tuner. *The phasing was correct. On 14 MHz where it becomes two stacked dipoles the SWR comes down and the performance goes up, but on 28 MHz it consistently lags behind a dipole. *I rebuilt this antenna twice. *If you actually go to the trouble of making one for 10 meters, and compare it to a real world 28 Mhz 1/2 wave dipole, the Lazy H will fall far short of the predicted gain. * I have been a ham since 1986. *I wondered why I had heard so few hams using a Lazy H, and the one time I recalled hearing one the signal was weaker than the other hams using a dipole. *I assumed at the time that I must have been off the side of the other ham's Lazy H, but after my real world test who knows. * I'm going to remove the center feed from the antenna this week, and rework the Lazy H for end feed with a twist, a matching stub, and 1/2 wave spacing. *Hopefully the end fed version of the Lazy H will live up to it's text book gain. *I'd really like to have that 6 dbd gain along with the nulls off the sides, Michael Rawls KS4HY On May 30, 5:48*pm, walt wrote: On May 30, 2:44*pm, Baron wrote: Michael Inscribed thus: * Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. *I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. *A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. * I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. *I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. *I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. *I made sure there was no twist in the ladder line connecting the top and bottom elements. * I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. *A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. * Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. *Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. *The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: * * * * * * * * * * * * * Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180°, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU One other thought, Michael, is that if you made the lazy-H with 1/2wl spacing for 20m and then use it on 10m, the spacing is now 1wl. I haven't seen any figures for that spacing, but isn't it possible that with that spacing the gain might not be what you expect? Especially if it works properly on 20m? Walt Hi Walt, I initially made the Lazy H for 5/8th wave spacing on 10 meters. When that did not work I reduced the spacing to 1/2 wave spacing on 10 meters. The 4 half wave elements are 1/2 waves on 10 meters. The antenna design is really pretty simple. I did make some contacts with this antenna and I received some good reports, but the dipole consistently out performed the Lazy H, There was one contact in Bermuda that said the Lazy H put in a stronger signal from South Carolina, but there was alot of fading at the time. Even when the Bermuda contact said the Lazy H put in the stronger signal the dipole was receiving the stronger signal from Bermuda. Michael |
The Lazy H does not seem to exhibit any gain over a dipole in the real world
"Baron" wrote in message ... Michael Inscribed thus: Tried mounting it horizontally ? -- Best Regards: Baron. I looked at that antenna in a handbook years ago. Could not tell from that how it is mounted. Do you mount the elements one over the top of the other, or do you mount them sideways like a 2 element horizontal beam ? |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 30, 10:57*pm, "Ralph Mowery"
wrote: "Baron" wrote in message ... Michael Inscribed thus: Tried mounting it horizontally ? -- Best Regards: * * * * * * * * * * * * *Baron. I looked at that antenna in a handbook years ago. *Could not tell from that how it is mounted. *Do you mount the elements one over the top of the other, or do you mount them sideways like a 2 element horizontal beam ? Yes. It is mounted horizontally. |
The Lazy H does not seem to exhibit any gain over a dipole inthe real world
I sort of think also, the Lazy H (think colinear?) should be fed and
phased with 75 ohm line. On Mon, 30 May 2011 14:48:45 -0700, walt wrote: If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 31, 11:07*am, Wond wrote:
* * *I sort of think also, the Lazy H (think colinear?) should be fed and phased with 75 ohm line. On Mon, 30 May 2011 14:48:45 -0700, walt wrote: If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU Another point to consider, Mark, is that the azimuth beam width is narrower with the lazy-H than that of the dipole. So perhaps the apparent lower signal level is in directions off the side of the radiation pattern, where one would expect the signal level to be lower than that of the dipole at the same angle. Walt |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 31, 1:07*pm, walt wrote:
On May 31, 11:07*am, Wond wrote: * * *I sort of think also, the Lazy H (think colinear?) should be fed and phased with 75 ohm line. On Mon, 30 May 2011 14:48:45 -0700, walt wrote: If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU Another point to consider, Mark, is that the azimuth beam width is narrower with the lazy-H than that of the dipole. So perhaps the apparent lower signal level is in directions off the side of the radiation pattern, where one would expect the signal level to be lower than that of the dipole at the same angle. Walt I "MAY" have figured out what was wrong with the Lazy H. This is a tentative post. The Lazy H is located in Charleston, South Carolina and it is broadside to Southern California. It should be aiming just barley north of West and just barely south of East. The first clue came when a station in the Caribbean gave me a 20 over S9 report. That direction should be in a null spot. The propagation has been coming in from Texas, Southern California, Central and South America, and the Northeast (New York, Mass, New Jersey, etc). Well today the propagation rolled in from the North west, and I saw a signal increase from a station in Iowa when I compared the Lazy H to the dipole. That is not the direction the Lazy H is facing, so it occurred to me there might be something skewing the propagation angle of the antenna to the north west and south east. Since there has not been any propagation from the North/west direction until today I had nothing to test it against. I went outside and noticed the 450 ohm feed line was not coming away from the Lazy H at a 90 degree angle. It was more of a 45 degree angle. I added some length to the 450 ohm ladder line, and then repositioned the feed line to come away from the Lazy H at a 90 degree angle. When I went back to test the antenna it was beginning to show gain in the intended direction. Also the tuner had an easier time matching the antenna. I may have to play with it some more, but I may have found the missing 5.9 dbd gain with 1/2 wave spacing. I'm going to keep my fingers crossed and hope I don't have to retract this post. Michael Rawls KS4HY |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On May 31, 11:45*pm, Michael wrote:
On May 31, 1:07*pm, walt wrote: On May 31, 11:07*am, Wond wrote: * * *I sort of think also, the Lazy H (think colinear?) should be fed and phased with 75 ohm line. On Mon, 30 May 2011 14:48:45 -0700, walt wrote: If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU Another point to consider, Mark, is that the azimuth beam width is narrower with the lazy-H than that of the dipole. So perhaps the apparent lower signal level is in directions off the side of the radiation pattern, where one would expect the signal level to be lower than that of the dipole at the same angle. Walt I "MAY" have figured out what was wrong with the Lazy H. *This is a tentative post. * The Lazy H is located in Charleston, South Carolina and it is broadside to Southern California. *It should be aiming just barley north of West and just barely south of East. *The first clue came when a station in the Caribbean gave me a 20 over S9 report. *That direction should be in a null spot. *The propagation has been coming in from Texas, Southern California, Central and South America, and the Northeast (New York, Mass, New Jersey, etc). * Well today the propagation rolled in from the North west, and I saw a signal increase from a station in Iowa when I compared the Lazy H to the dipole. *That is not the direction the Lazy H is facing, so it occurred to me there might be something skewing the propagation angle of the antenna to the north west and south east. *Since there has not been any propagation from the North/west direction until today I had nothing to test it against. * I went outside and noticed the 450 ohm feed line was not coming away from the Lazy H at a 90 degree angle. * It was more of a 45 degree angle. *I added some length to the 450 ohm ladder line, and then repositioned the feed line to come away from the Lazy H at a 90 degree angle. *When I went back to test the antenna it was beginning to show gain in the intended direction. *Also the tuner had an easier time matching the antenna. *I may have to play with it some more, but I may have found the missing 5.9 dbd gain with 1/2 wave spacing. *I'm going to keep my fingers crossed and hope I don't have to retract this post. Michael Rawls KS4HY Just a quick update. I am seeing some gain with the Lazy H now that the feed line exiting the antenna has been moved to a 90 degree angle, but I don't think I am seeing the 5.9 dbd gain promised in the ARRL Antenna Handbook. I would guess it is more around 3 or 4 dbd gain with 1/2 wave length elements and 1/2 wave spacing between the top and bottom elements. It seems like alot of trouble to go to when an extended double zepp at the same height as top wire of the Lazy H might do just as well if not better. The plus is the Lazy H may have cleaner nulls off the sides which is helping with the occasional AM carriers that are coming out of Central and South America. Michael |
The Lazy H does not seem to exhibit any gain over a dipole inthe real world
On 6/2/2011 1:27 PM, Michael wrote:
Just a quick update. I am seeing some gain with the Lazy H now that the feed line exiting the antenna has been moved to a 90 degree angle, but I don't think I am seeing the 5.9 dbd gain promised in the ARRL Antenna Handbook. I would guess it is more around 3 or 4 dbd gain with 1/2 wave length elements and 1/2 wave spacing between the top and bottom elements. It seems like alot of trouble to go to when an extended double zepp at the same height as top wire of the Lazy H might do just as well if not better. The plus is the Lazy H may have cleaner nulls off the sides which is helping with the occasional AM carriers that are coming out of Central and South America. Michael Just curious, how are you measuring this -2 to -3 dB difference you are referencing? tom K0TAR |
The Lazy H does not seem to exhibit any gain over a dipole in the real world
Walt, you continue to amaze me with your apparently wonderful and extensive
knowledge with antennas and transmission lines. I look forward to finding threads where you have entered a discussion on some topic or other. I have been a Ham since 1958. I've studied, and read lots on the subject and always wished, but was never able to really understand the aforementioned topics to any degree. I've built and played around with many antennas over the years. Reading this newsgroup and many of the discussions has taught me a lot, but your ability to relate various aspects which might to me be seemingly unrelated, and put them into words which are both meaningful and understandable blows my mind. Your replies advising Michael on just this thread alone have been great. I've been meaning to say this for years -- now here it is -- Thanks for being around and sharing your goodies with us all. Irv VE6BP "walt" wrote in message ... On May 30, 9:31 pm, Michael wrote: Thanks for your input Walt, but I already thought of those things. I definitely made the antenna correctly. According to the ARRL handbook when center feeding the Lazy H increasing the spacing beyond 1/2 wave makes the gain go up until the spacing reaches 5/8ths wave. The handbooks states 5.9 dbd gain for 1/2 wave spacing and 6.7 dbd for 5/8ths wave spacing. In the real world this antenna does not have any gain over a 1/2 wave dipole when center fed with 450 ohm ladder line all the way back to the tuner. The phasing was correct. On 14 MHz where it becomes two stacked dipoles the SWR comes down and the performance goes up, but on 28 MHz it consistently lags behind a dipole. I rebuilt this antenna twice. If you actually go to the trouble of making one for 10 meters, and compare it to a real world 28 Mhz 1/2 wave dipole, the Lazy H will fall far short of the predicted gain. I have been a ham since 1986. I wondered why I had heard so few hams using a Lazy H, and the one time I recalled hearing one the signal was weaker than the other hams using a dipole. I assumed at the time that I must have been off the side of the other ham's Lazy H, but after my real world test who knows. I'm going to remove the center feed from the antenna this week, and rework the Lazy H for end feed with a twist, a matching stub, and 1/2 wave spacing. Hopefully the end fed version of the Lazy H will live up to it's text book gain. I'd really like to have that 6 dbd gain along with the nulls off the sides, Michael Rawls KS4HY On May 30, 5:48 pm, walt wrote: On May 30, 2:44 pm, Baron wrote: Michael Inscribed thus: Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. I made sure there was no twist in the ladder line connecting the top and bottom elements. I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180°, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU One other thought, Michael, is that if you made the lazy-H with 1/2wl spacing for 20m and then use it on 10m, the spacing is now 1wl. I haven't seen any figures for that spacing, but isn't it possible that with that spacing the gain might not be what you expect? Especially if it works properly on 20m? Walt |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
I'm definitely using a less than scientific method, so don't take my
estimation as solid proof. It is just a guess at best. Michael On Jun 2, 10:48*pm, tom wrote: On 6/2/2011 1:27 PM, Michael wrote: * *Just a quick update. *I am seeing some gain with the Lazy H now that the feed line exiting the antenna has been moved to a 90 degree angle, but I don't think I am seeing the 5.9 dbd gain promised in the ARRL Antenna Handbook. *I would guess it is more around 3 or 4 dbd gain with 1/2 wave length elements and 1/2 wave spacing between the top and bottom elements. *It seems like alot of trouble to go to when an extended double zepp at the same height as top wire of the Lazy H might do just as well if not better. *The plus is the Lazy H may have cleaner nulls off the sides which is helping with the occasional AM carriers that are coming out of Central and South America. Michael Just curious, how are you measuring this -2 to -3 dB difference you are referencing? tom K0TAR |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On Jun 2, 11:03*pm, "Irv Finkleman" wrote:
Walt, you continue to amaze me with your apparently wonderful and extensive knowledge with antennas and transmission lines. *I look forward to finding threads where you have entered a discussion on some topic or other. *I have been a Ham since 1958. I've studied, and read lots on the subject and always wished, but was never able to really understand the aforementioned topics to any degree. *I've built and played around with many antennas over the years. Reading this newsgroup and many of the discussions has taught me a lot, but your ability to relate various aspects which might to me be seemingly unrelated, and put them into words which are both meaningful and understandable blows my mind. *Your replies advising Michael on just this thread alone have been great. I've been meaning to say this for years -- now here it is -- Thanks for being around and sharing your goodies with us all. Irv VE6BP "walt" wrote in message ... On May 30, 9:31 pm, Michael wrote: Thanks for your input Walt, but I already thought of those things. I definitely made the antenna correctly. According to the ARRL handbook when center feeding the Lazy H increasing the spacing beyond 1/2 wave makes the gain go up until the spacing reaches 5/8ths wave. The handbooks states 5.9 dbd gain for 1/2 wave spacing and 6.7 dbd for 5/8ths wave spacing. In the real world this antenna does not have any gain over a 1/2 wave dipole when center fed with 450 ohm ladder line all the way back to the tuner. The phasing was correct. On 14 MHz where it becomes two stacked dipoles the SWR comes down and the performance goes up, but on 28 MHz it consistently lags behind a dipole. I rebuilt this antenna twice. If you actually go to the trouble of making one for 10 meters, and compare it to a real world 28 Mhz 1/2 wave dipole, the Lazy H will fall far short of the predicted gain. I have been a ham since 1986. I wondered why I had heard so few hams using a Lazy H, and the one time I recalled hearing one the signal was weaker than the other hams using a dipole. I assumed at the time that I must have been off the side of the other ham's Lazy H, but after my real world test who knows. I'm going to remove the center feed from the antenna this week, and rework the Lazy H for end feed with a twist, a matching stub, and 1/2 wave spacing. Hopefully the end fed version of the Lazy H will live up to it's text book gain. I'd really like to have that 6 dbd gain along with the nulls off the sides, Michael Rawls KS4HY On May 30, 5:48 pm, walt wrote: On May 30, 2:44 pm, Baron wrote: Michael Inscribed thus: Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. I made sure there was no twist in the ladder line connecting the top and bottom elements. I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180�, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU One other thought, Michael, is that if you made the lazy-H with 1/2wl spacing for 20m and then use it on 10m, the spacing is now 1wl. I haven't seen any figures for that spacing, but isn't it possible that with that spacing the gain might not be what you expect? Especially if it works properly on 20m? Walt This Lazy H is specifically made for 10 meters, the summer Sporadic E season, and the steadily climbing solar flux. I almost never use 20 meters. Michael KS4HY |
The Lazy H does not seem to exhibit any gain over a dipole in thereal world
On Jun 3, 9:14*am, Michael wrote:
On Jun 2, 11:03*pm, "Irv Finkleman" wrote: Walt, you continue to amaze me with your apparently wonderful and extensive knowledge with antennas and transmission lines. *I look forward to finding threads where you have entered a discussion on some topic or other. *I have been a Ham since 1958. I've studied, and read lots on the subject and always wished, but was never able to really understand the aforementioned topics to any degree. *I've built and played around with many antennas over the years. Reading this newsgroup and many of the discussions has taught me a lot, but your ability to relate various aspects which might to me be seemingly unrelated, and put them into words which are both meaningful and understandable blows my mind. *Your replies advising Michael on just this thread alone have been great. I've been meaning to say this for years -- now here it is -- Thanks for being around and sharing your goodies with us all. Irv VE6BP "walt" wrote in message .... On May 30, 9:31 pm, Michael wrote: Thanks for your input Walt, but I already thought of those things. I definitely made the antenna correctly. According to the ARRL handbook when center feeding the Lazy H increasing the spacing beyond 1/2 wave makes the gain go up until the spacing reaches 5/8ths wave. The handbooks states 5.9 dbd gain for 1/2 wave spacing and 6.7 dbd for 5/8ths wave spacing. In the real world this antenna does not have any gain over a 1/2 wave dipole when center fed with 450 ohm ladder line all the way back to the tuner. The phasing was correct. On 14 MHz where it becomes two stacked dipoles the SWR comes down and the performance goes up, but on 28 MHz it consistently lags behind a dipole. I rebuilt this antenna twice. If you actually go to the trouble of making one for 10 meters, and compare it to a real world 28 Mhz 1/2 wave dipole, the Lazy H will fall far short of the predicted gain. I have been a ham since 1986. I wondered why I had heard so few hams using a Lazy H, and the one time I recalled hearing one the signal was weaker than the other hams using a dipole. I assumed at the time that I must have been off the side of the other ham's Lazy H, but after my real world test who knows. I'm going to remove the center feed from the antenna this week, and rework the Lazy H for end feed with a twist, a matching stub, and 1/2 wave spacing. Hopefully the end fed version of the Lazy H will live up to it's text book gain. I'd really like to have that 6 dbd gain along with the nulls off the sides, Michael Rawls KS4HY On May 30, 5:48 pm, walt wrote: On May 30, 2:44 pm, Baron wrote: Michael Inscribed thus: Well I've worked with the center fed Lazy H antenna design on 10 meters for several few weeks now. I tried 1/2 wave spacing between the top and bottom elements, 5/8th wave spacing between the top and bottom elements, I put it up at 40 feet and 50 feet at the top wire, I tried different lengths of 450 ohm feed-line, and this antenna consistently under performs a 1/2 wave dipole cut for the same frequency. A simple 1/2 wave dipole consistently out performs the center fed version of Lazy H antenna even when the Lazy H is given a 20 foot height advantage over the lowly dipole. I even put up the Lazy H in two completely different locations over 180 miles apart. I also tried two completely different antenna tuners (Dentron MT-3000a and Drake MN-75 with the 4:1 balun installed). Out of over 200 A/B test the Lazy H antenna only out performed the dipole on one test with a station in Texas just before the propagation faded out for the day, The next day when the propagation was back I heard the same station on the same frequency and the dipole out performed the Lazy H for the rest of the day. I'm not sure what special propagation mode is required for the Lazy H to have some gain through some pin hole direction, but the version of the Lazy H center fed with 450 ohm ladder line back to the antenna tuner is a complete failure. I even re-built the antenna from scratch using a different piece 450 ladder line for the inter connecting piece. I also verified the length of each 1/2 wave section with a tape measure. I verified with an ohm meter that the top left element was connected to the bottom left element and the right top element was connected to the bottom right element. I verified there was no unexpected connectivity between the left and right elements, and I verified both sides of the ladder line were connected back to the antenna tuner. I made sure there was no twist in the ladder line connecting the top and bottom elements.. I would like to petition the ARRL to remove the center fed Lazy H from the antenna handbook as it clearly does not work as specified. A lowly mono band dipole on the same design frequency will consistently out perform the center feed Lazy H even when the Lazy H is given a 20 foot height advantage on10 meters. Before any of you reply with charts and graphs from EZNEC software, turn off your computer, go out in the back yard, and actually build a center fed Lazy H antenna with 450 ladder line all the way back to the antenna tuner. Then do real world A/B comparisons with a plain old mono band dipole cut for the same frequency, and you will find I am telling the truth. The center fed Lazy H does not have any gain over a 1/2 wave dipole broadside to the antenna. None. Here is what you will fine if you actually build the center fed Lazy H and compare it to a 1/2 wave mono band dipole cut for the same same frequency; 1) Your tuner will have to use extreme setting to match the Lazy H. 2) In some instances the tuner will not be able to match the Lazy H depending on the length of the ladder line feeding the antenna. You may have to increase or decrease the length of the ladder line feeding the Lazy H to get your antenna tuner to match it. 3) A 1/2 wave dipole will beat the Lazy H 99.99 percent of the time in it's favored direction even if the Lazy H is given a 20 foot height advantage over the dipole. 4) An extended double zepp with a 450 ohm matching section back to a 1:1 balun and then to 50 ohm coax cut for the same frequency and hung from the same ropes previously used to support the Lazy H will blow the Lazy H in the dirt. In a nutshell, this antenna sucks! Michael Rawls KS4HY Tried mounting it horizontally ? -- Best Regards: Baron. Hi Michael, I'm sorry to hear you think the lazy-H sucks. I used one on 20m years ago and it worked just fine--and no trouble in matching it with a tuner. However, I have a suggestion: Let's say you space the upper and lower radiating elements by 180�, which is 1/2wl. If you now use 450-ohm window line, the velocity factor for the line attaching the two elements together makes the electrical length of the line greater than 1/2wl, which means the phasing between the upper and lower elements is no longer correct, and therefore will not provide the expected gain.. I'm not sure how much phasing error that will produce, but it's an issue you should consider. Correctly constructed, the lazy-H will definitely out perform a 1/2wl dipole, so if it doesn't for you there is sum ting definitely wong! If you feed at the center of the line connecting the two radiating elements the phasing will be correct regardless of the velocity factor, because the length from the center feed point on the connecting line will be the same from that point to each radiating element. With this configuration of feeding don't put a twist in the connecting line--the two radiating elements MUST be fed IN PHASE! If they're fed out of phase the array will look like an Adcock direction- finding antenna, with a deep null in the radiation pattern in the broadside direction. Just my thoughts, Walt, W2DU One other thought, Michael, is that if you made the lazy-H with 1/2wl spacing for 20m and then use it on 10m, the spacing is now 1wl. I haven't seen any figures for that spacing, but isn't it possible that with that spacing the gain might not be what you expect? Especially if it works properly on 20m? Walt This Lazy H is specifically made for 10 meters, the summer Sporadic E season, and the steadily climbing solar flux. I almost never use 20 meters. Michael KS4HY Thank you Irv, for the nice words you posted about me. I was fortunate to have been an antenna engineer with RCA for 31 years, where I was surrounded with professionals who were in the top echelon of antenna developers. I've had no other formal training in engineering other than my close association with them, and studying their voluminous text books. Learning as a ham (78 yrs continually licensed since 1933) is clearly the root of my engineering knowledge. Do you have a copy of my book, "Reflections--Transmission Lines and Antennas? If not, some of the chapters from the book are available for downloading at my web page at www.w2du.com. Thanks again, Irv, Walt, W2DU |
The Lazy H does not seem to exhibit any gain over a dipole in the real world
Do you have a copy of my book, "Reflections--Transmission Lines and Antennas? If not, some of the chapters from the book are available for downloading at my web page at www.w2du.com. Thanks again, Irv, Walt, W2DU Wow! Impressive resume Walt. It's funny you should ask about 'Refections'. I never had the book, but did download and study the available chapters from your website. Due to some pretty serious illness and surgery during the past two years I had to sell my house. At the same time my prognosis was so limited that I gave away all my equipment, tools, parts, and books -- most of it to other hams as well as our local radio club. I had more antenna books than anything. We never dreamed I would be in condition to operate a station again and it wasn't easy giving up one of my great loves in life -- HAM RADIO! As per Murphy's Laws, my recovery was remarkable, but I had to move into a seniors residence where nursing assistance was available, and since then I have had restorative surgery and am in pretty good condition again. I am now ready to resume my participation in the hobby, but in a very downsized manner. I just bought a Yaesu FT-817ND (an all band/mode QRP rig, the only rig I ever bought brand new) and am in the process of building a magnetic loop antenna which I can cleverly conceal on my balcony. Basically it is a very simple project, considering the fact that I will be operating either 5w or 2.5w and do not have to go overboard on a HV tuning cap. I've always been a low power operator, knowing that with a little operating skill, and a 'decent' antenna you don't need a lot to have a bundle of fun. The snow has just cleared from my area (Calgary, Alberta) and I should be up and operating pretty soon (as soon as I can concoct a simple insulated coupling between the tuning cap drive motor and the capacitor). The principles of the magnetic loop are simple, and I have been able to download lots of good hints and kinks over the net -- more than I need. So I'm a long way from dead, and looking forward to resuming the hobby which has kept me fully occupied for many years. I've helped many fellow hams with invisible antennas -- now it's my turn and I'm approaching it with a very optomistic outlook. Starting over is not difficult -- once you have the knowledge, the rest is easy. Maybe we'll meet around the bands someday. Thanks again for all you've given to the hobby! Ohm's Law was easy, but we needed folks like you for the antenna understanding. Irv, VE6BP |
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