11 Meter to 10 Meter Yagi Antenna Conversion
Hi,
Does anyone have a formula or know a technique for converting an 11 meter 3 element yagi antenna into a 10 meter yagi (beam antenna)? Thanks in advance, Brad Before you type your password, credit card number, etc., be sure there is no active key logger (spyware) in your PC. |
11 Meter to 10 Meter Yagi Antenna Conversion
Brad wrote:
Hi, Does anyone have a formula or know a technique for converting an 11 meter 3 element yagi antenna into a 10 meter yagi (beam antenna)? Thanks in advance, Brad Before you type your password, credit card number, etc., be sure there is no active key logger (spyware) in your PC. Well, wouldn't it be 10/11 length of each element? Get a big wire cutter and have at it. GG |
11 Meter to 10 Meter Yagi Antenna Conversion
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11 Meter to 10 Meter Yagi Antenna Conversion
"Brad" wrote in message
... Hi, Does anyone have a formula or know a technique for converting an 11 meter 3 element yagi antenna into a 10 meter yagi (beam antenna)? Thanks in advance, Brad Brad - First, What 11 meter beam is this? Manufacturer? Did you know that many manufacturers have this information in their assembly instructions? Have your amateur radio license yet? I provide assistance for licensed amateurs. Google will lead you to answer. gb |
11 Meter to 10 Meter Yagi Antenna Conversion
On Sat, 17 Jun 2006 15:33:56 GMT, (Brad) wrote:
Does anyone have a formula or know a technique for converting an 11 meter 3 element yagi antenna into a 10 meter yagi (beam antenna)? Sure. Take your current antenna dimensions and plug them into an antenna modeling package such as: 4NEC2 (free) http://home.ict.nl/~arivoors/ Eznec (free demo) http://www.eznec.com or any of those listed at: http://www.si-list.org/swindex2.html Insert your current antenna dimensions into the program and make sure it works at 11 meters. Then, change the frequency to 10 meters and run the optimizer. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
11 Meter to 10 Meter Yagi Antenna Conversion
"Brad" wrote in message
... Hi, Does anyone have a formula or know a technique for converting an 11 meter 3 element yagi antenna into a 10 meter yagi (beam antenna)? Thanks in advance, Brad Before you type your password, credit card number, etc., be sure there is no active key logger (spyware) in your PC. The frequency difference might be insignificant if your antenna tuner can accommodate the differences. The 10-meter band is lower in frequency than the 11-meter band, therefore all elements would have to be lengthened by a small amount to get it exactly right. Google around for yagi antenna design software. There are probably a number of freebies available. I Googled for yagi antenna design and the second hit came up with http://www.hamuniverse.com/yagibasics.html, which should give your answer. Cheers!! -- Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in the address) Some days you're the dog, some days the hydrant. |
11 Meter to 10 Meter Yagi Antenna Conversion
DaveM wrote:
The frequency difference might be insignificant if your antenna tuner can accommodate the differences. The 10-meter band is lower in frequency than the 11-meter band, therefore all elements would have to be lengthened by a small amount to get it exactly right. Sorry, it's not. The eleven meter band, aka CB, is in the 27mHz range. The 10m Ham band is 28.0 to 29.7 mHz, but most people don't use the whole band. 28.0-28.3 is mostly CW (Morse code) because the U.S. prohibits usage of voice signals there. SSB and AM voice signals are legal in the rest of the band, but most often they are found in the 28.5-29.0 range. FM voice is limited in the U.S. to 29.0 and up, and FM repeaters use 29.5 to 29.6 for TRANSMISSION. While it would be best to shorten all of the elements, and move them closer together, it is really only necessary to shorten the driven element (where the radio connects) and the director (the one in front of it). You can do it simply by measuring them and cuting off the ends to make them 27/28ths of the size they were. Modeling the antenna with computer software would save you a lot of time and trouble, or carefully modifying it by cutting and trying it with an SWR meter or an antenna analyzer. Keep in mind that you need a valid ham license in most countries to transmit on 10 meters. If you do not have a license and are planing to get one in the future, don't bother modifying it. The difference in reception is not really worth it. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
11 Meter to 10 Meter Yagi Antenna Conversion
Jeff Liebermann wrote:
I don't think the original poster is interested in becoming a ham and using the 10 meter ham band allocations. My guess(tm) is that he's interested in "freeband" radio. Freeband is located in between the CB band and the 10 meter ham band from 27.410 to 28.000Mhz. Operation in this area is strictly illegal, but that doesn't seem to prevent Freeband operators from doing so, or seem to interest the FCC enforcement burro. For example: I assume nothing. Outside of the U.S. the bands are different, enforcement is different,e tc. For example in the E.U., you can use a regular ham radio on CB, no one seems to care about the power. FM and packet are also common on CB. Since I've been here in Israel (almost 10 years), I've never met a person with a CB. I occasionaly scan through the bands, but I never hear anyone on 2m, 10m, and CB. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
11 Meter to 10 Meter Yagi Antenna Conversion
"DaveM" wrote in message . .. The frequency difference might be insignificant if your antenna tuner can accommodate the differences. The 10-meter band is lower in frequency than the 11-meter band, therefore all elements would have to be lengthened by a small amount to get it exactly right. Google around for yagi antenna design software. There are probably a number of freebies available. No, the higher the frequency, the shorter the wavelength. |
11 Meter to 10 Meter Yagi Antenna Conversion
In message , Geoffrey S.
Mendelson writes Jeff Liebermann wrote: I don't think the original poster is interested in becoming a ham and using the 10 meter ham band allocations. My guess(tm) is that he's interested in "freeband" radio. Freeband is located in between the CB band and the 10 meter ham band from 27.410 to 28.000Mhz. Operation in this area is strictly illegal, but that doesn't seem to prevent Freeband operators from doing so, or seem to interest the FCC enforcement burro. For example: I assume nothing. Outside of the U.S. the bands are different, enforcement is different,e tc. For example in the E.U., you can use a regular ham radio on CB, no one seems to care about the power. FM and packet are also common on CB. You certainly can NOT legally use "a regular ham radio on CB" (at least not in the UK), even if you keep to the 4W power limit. CB radios have to be type approved to be legal. If you are a licensed radio amateur, you can, of course, modify a legal CB radio for use on the 10m band (or, for that matter, any other amateur band). However, the authorities are (or were) a little difficult about modifying illegal CB radios for amateur use, on the grounds that they were not approved, so could not have been legally imported into the UK. No import duty could have been paid, so they must have been smuggled here. Since I've been here in Israel (almost 10 years), I've never met a person with a CB. I occasionaly scan through the bands, but I never hear anyone on 2m, 10m, and CB. Don't know why you've never heard anyone on 2m or 10m (but I can't speak for CB). As for the original question, I don't see why an 11m beam can not be trimmed a little to move it up into the 10m band. I doubt if you will need to reduce the spacing between the elements. Cheers. Ian. -- |
11 Meter to 10 Meter Yagi Antenna Conversion
(Geoffrey S. Mendelson) hath wroth:
Jeff Liebermann wrote: I don't think the original poster is interested in becoming a ham and using the 10 meter ham band allocations. My guess(tm) is that he's interested in "freeband" radio. Freeband is located in between the CB band and the 10 meter ham band from 27.410 to 28.000Mhz. Operation in this area is strictly illegal, but that doesn't seem to prevent Freeband operators from doing so, or seem to interest the FCC enforcement burro. For example: I assume nothing. You assumed that the original poster wanted to operate in the 10 meter ham band, and not between the ham band and CB. Outside of the U.S. the bands are different, enforcement is different,e tc. True. World wide, the area between 27.410 to 28.000MHz is either meteorological, or commercial ISM service. See: http://www.fcc.gov/oet/spectrum/table/fcctable.pdf Page 15. The 2 columns are for international and US allocations. Note that none of them include Part 95 (CB) or part 97 (Ham). Your non-assumption is wrong. For example in the E.U., you can use a regular ham radio on CB, no one seems to care about the power. FM and packet are also common on CB. I do PSK31 on CB just to see if it can get through the interference. Seems to work quite well. Just because nobody cares, or nobody enforces the rules, doesn't make it legal. Since I've been here in Israel (almost 10 years), I've never met a person with a CB. I occasionaly scan through the bands, but I never hear anyone on 2m, 10m, and CB. See: http://w3.iarc.org/repeater/ http://www.iarc.org/repeater/LIST.htm I was in Haifa in Dec 2000, and found it fully occupied by jammers from both sides of the political spectrum. Has the repeater network been abandoned? Perhaps if you listen during one of the weekly nets: http://w3.iarc.org/nets/nets.html Geoff. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
11 Meter to 10 Meter Yagi Antenna Conversion
Ian Jackson wrote:
You certainly can NOT legally use "a regular ham radio on CB" (at least not in the UK), even if you keep to the 4W power limit. CB radios have to be type approved to be legal. The U.K.may be the exception. I have seen articles in radio magazines back when I could get them, showing ham radios used on CB in continental Europe, Spain, France, the Netherlands. If it was legal or not, the articles and pictures were there. Don't know why you've never heard anyone on 2m or 10m (but I can't speak for CB). There is a 2m repeater here, but if it used more than an hour a week I'd be surprised. I've monitored it randomly and occasionaly for several days at a time, and it is unused. There may be more activity in the north, but not here. When I moved here in '96 the local repeater id'ed as "This is R1 Jerusalem open to all" in English and this is R1 Jerusalem in Hebrew. Now there is just an occasional high speed CW ID and often that's all I hear the entire day. Ten meters is even less used. I can't hear any repeaters, maybe in a few years when the sunspots are back. On the SSB/CW end of the band nothing. 40 and 20 are busy sometimes. Propigation varies on 20, sometimes nothing, sometimes open. When it is open it's usually around sunrise/sunset and you can hear the band following the Sun. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
11 Meter to 10 Meter Yagi Antenna Conversion
"Michael Ware" wrote in message
.. . "DaveM" wrote in message . .. The frequency difference might be insignificant if your antenna tuner can accommodate the differences. The 10-meter band is lower in frequency than the 11-meter band, therefore all elements would have to be lengthened by a small amount to get it exactly right. Google around for yagi antenna design software. There are probably a number of freebies available. No, the higher the frequency, the shorter the wavelength. Yes, of course you are all correct, and I was totally wrong. I know better... just don't know what happened to my thinking before I started typing. -- Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in the address) Some days you're the dog, some days the hydrant. |
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