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Post by westom on Mar 2, 2016 22:45:09 GMT -5
Also I hear that higher isnt always better, which i think is a lie. because in a mobile when you are driving and dip into a hole you are pretty much dead, but going up the other side of the mountain and once on top it is clear and the signal is strong again. Do not confuse electromagnetic characteristics of the antenna with wave propagation over kilometers. EM characteristics are determined by what exists within a wavelength of that antenna. Relevant EM parameters change significance when that field is a kilometer away. If that antenna needs a ground plane, that ground plane would be less than a wavelength away. If the antenna is higher, a ground plane must be created below that antenna. Or an antenna of different design is needed. All that is about an antenna's EM characteristics. A higher antenna means a horizon's radius is farther. That is completely different from an antenna's EM characteristics.
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on Mar 3, 2016 8:46:00 GMT -5
Doing some reading and learning things. But are they the truth? I hear the rule of thumb for a base antenna is the base should be set at 36' off the ground? If I go higher a groundplane kit is in need for the antenna to work properly, ?? Talking about an Imax 2000. My setup when said and done the base will be around 45'-50' up the tower, then the rest of the antenna from that point. Will I need a groundplane kit for this? Also I hear that higher isnt always better, which i think is a lie. because in a mobile when you are driving and dip into a hole you are pretty much dead, but going up the other side of the mountain and once on top it is clear and the signal is strong again. So thats why I think high is better. Please tell me if this is the same for a base antenna being high. Thanks That 36' number corresponds to a full wavelength above ground at 27 Mhz. Operating at that height or higher gives you the lowest angle of radiation toward the horizon. All vertical antennas should have a ground plane counterpoise to be most effective. Antennas mounted on the ground, and utilize the conductive nature of the soil as the ground plane. For those raised up higher, an artificial ground needs to be incorporated, which is what the horizontal (and parallel to the ground) radials do. 36' is a minimum height for best radiation. You can go higher. Usually, the higher you go, the further your signal will travel to the horizon. There has been much discussion over whether a ground plane kit for A99 and IMAX type stick antennas really makes a difference, and the consensus seems to be that it does help, although the gain is not drastic. My bigger concern with stick type antennas is the lack of proper RF decoupling that the ground plane usually takes care of. Without good RF decoupling, stray RF currents can (and usually do) travel down the shield of the feedline, which can result in a "hot" shack (microphone squeals, and other cases of RF feedback), and increased near-field RFI issues. Some of that can be minimized by constructing an RF choke with a few coils of feedline just below the antenna feedpoint. But if it were me, I'd opt for an aluminum .64 wave antenna with the proper radials.
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Post by whitetail on Mar 3, 2016 22:17:38 GMT -5
Doing some reading and learning things. But are they the truth? I hear the rule of thumb for a base antenna is the base should be set at 36' off the ground? If I go higher a groundplane kit is in need for the antenna to work properly, ?? Talking about an Imax 2000. My setup when said and done the base will be around 45'-50' up the tower, then the rest of the antenna from that point. Will I need a groundplane kit for this? Also I hear that higher isnt always better, which i think is a lie. because in a mobile when you are driving and dip into a hole you are pretty much dead, but going up the other side of the mountain and once on top it is clear and the signal is strong again. So thats why I think high is better. Please tell me if this is the same for a base antenna being high. Thanks That 36' number corresponds to a full wavelength above ground at 27 Mhz. Operating at that height or higher gives you the lowest angle of radiation toward the horizon. All vertical antennas should have a ground plane counterpoise to be most effective. Antennas mounted on the ground, and utilize the conductive nature of the soil as the ground plane. For those raised up higher, an artificial ground needs to be incorporated, which is what the horizontal (and parallel to the ground) radials do. 36' is a minimum height for best radiation. You can go higher. Usually, the higher you go, the further your signal will travel to the horizon. There has been much discussion over whether a ground plane kit for A99 and IMAX type stick antennas really makes a difference, and the consensus seems to be that it does help, although the gain is not drastic. My bigger concern with stick type antennas is the lack of proper RF decoupling that the ground plane usually takes care of. Without good RF decoupling, stray RF currents can (and usually do) travel down the shield of the feedline, which can result in a "hot" shack (microphone squeals, and other cases of RF feedback), and increased near-field RFI issues. Some of that can be minimized by constructing an RF choke with a few coils of feedline just below the antenna feedpoint. But if it were me, I'd opt for an aluminum .64 wave antenna with the proper radials. So what you are saying at the 36' height or higher will give me the lowest angle of radiation toward the horizon? What does this mean? So reading down your post, you say (the higher you go, the further your signal will travel to the horizon) this is what you want, correct? Sorry for asking but I dont follow you on this. What do you mean traveling to the horizon? I plan on doing an rf choke or loop at the bottom of the feedpoint of my antenna, so hopefully this should keep stray rf currents out. I may run the Imax for a year to see how it performs up there, then I might put up a sirio gain master, Iam reading up on those as well, (any info you have please share). Ultimately I just want a my station to be setup right the 1st time. And if higher is not good I can leave a section of tower off and bee in the 30'-36' range. Will 15' taller make a difference with the 36 rule, how much? My goal was 45'-50' if thats not doable or will hurt my signal Like I said I can leave a section off. Thanks for helping me understand this.
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on Mar 4, 2016 7:16:22 GMT -5
That 36' number corresponds to a full wavelength above ground at 27 Mhz. Operating at that height or higher gives you the lowest angle of radiation toward the horizon. All vertical antennas should have a ground plane counterpoise to be most effective. Antennas mounted on the ground, and utilize the conductive nature of the soil as the ground plane. For those raised up higher, an artificial ground needs to be incorporated, which is what the horizontal (and parallel to the ground) radials do. 36' is a minimum height for best radiation. You can go higher. Usually, the higher you go, the further your signal will travel to the horizon. There has been much discussion over whether a ground plane kit for A99 and IMAX type stick antennas really makes a difference, and the consensus seems to be that it does help, although the gain is not drastic. My bigger concern with stick type antennas is the lack of proper RF decoupling that the ground plane usually takes care of. Without good RF decoupling, stray RF currents can (and usually do) travel down the shield of the feedline, which can result in a "hot" shack (microphone squeals, and other cases of RF feedback), and increased near-field RFI issues. Some of that can be minimized by constructing an RF choke with a few coils of feedline just below the antenna feedpoint. But if it were me, I'd opt for an aluminum .64 wave antenna with the proper radials. So what you are saying at the 36' height or higher will give me the lowest angle of radiation toward the horizon? What does this mean? So reading down your post, you say (the higher you go, the further your signal will travel to the horizon) this is what you want, correct? Sorry for asking but I dont follow you on this. What do you mean traveling to the horizon? I plan on doing an rf choke or loop at the bottom of the feedpoint of my antenna, so hopefully this should keep stray rf currents out. I may run the Imax for a year to see how it performs up there, then I might put up a sirio gain master, Iam reading up on those as well, (any info you have please share). Ultimately I just want a my station to be setup right the 1st time. And if higher is not good I can leave a section of tower off and bee in the 30'-36' range. Will 15' taller make a difference with the 36 rule, how much? My goal was 45'-50' if thats not doable or will hurt my signal Like I said I can leave a section off. Thanks for helping me understand this. The pic's below illustrate a typical antenna radiation pattern in the vertical plane (Looking at it from the side). For local communication (and really long distance F layer DX), you want your signal heading out as close to flat as possible as the first image illustrates. Operating the antenna at a lower than 36' height, or without the proper radial counterpoise, will raise the angle of those RF lobes as shown in the second image. This might be desirable for shorter E-layer skip, but when you are talking local, you are wasting your signal, by aiming for the clouds, when you want your signal to reach places at ground level. Don't sweat the minor details though. There is no cast in stone "sweet spot" rule when it comes to antenna height. Yes, there are optimal heights for specific types of skip conditions. I know hams with motorized tower winches, who can raise and lower their antennas to optimize the received signal level based on where the signals are coming from. But that is way more trouble than is needed for the average radio op. Put your antenna up as high as you can practically do.
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Post by BBB on Mar 4, 2016 11:41:16 GMT -5
I you plan on running anything bigger than a (3) pill amplifier, I would look carefully at the Gain Master wattage specs. Sirio Gain-Master Hi-Tech Fiberglass 10m & CB Base Antenna: Max Power 500 Watts (CW) continuous, 1000 Watts (CW) short time. There is talk that Sirio will be releasing a shorter version of this antenna to be marketed as the Gain Master HW ("Half Wave" not High Wattage) Solarcon I-Maxx 2000:2000 watts (CW) short time power handling. No (CW) continuous rating given. (I have seen where it was published that it has been tested to 5000 watts short term, but doubt that claim. PL connector inserts start to melt at that RF power level) Both antennas are constructed of non-conductive fiberglass which is safer if the antenna topples in the proximity of overhead high voltage power lines. I run a Sirio 2016 and a home made ugly balun under it with great success at 36' above grade: Omni-directional, high power handling capability Low radiation angle Multi element ground plane (with 16 solid aluminum rods) Protection from static discharges (Capacitor Hat on top) Transformer DC-ground Base Connector: UHF-female directly under the large diameter base plate (shielded somewhat from direct rain) Made of aluminum alloy 6063 T-832 Type: 5/8 ground plane Frequency range: tune-able from 26.4 to 28.2 MHz Max. power: 1000 Watts (CW) continuous 3000 Watts (CW) short time www.sirioantenna.com/index.php?main_page=product_info&cPath=2_18&products_id=184&zenid=b7ad6ccb0c6be1de0c538652fe92b6fe
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Post by Night Ranger on Mar 5, 2016 9:36:34 GMT -5
I been wanting to put up a base antenna now for awhile, I will admit that Iam afraid of lightning! Who isnt? Last fall I bought a new Imax 2000 and put the base at 20' off the ground, attached to 2 pieces of 10'Pipe strapped to my porch post. I took it down in april when the storm season started. It worked great swr was flat and I talked all over that winter. My goal was to put up my 40' tower I have had in the shed now for 4 yrs, and fly the Imax on top of that!! That thing would rock right? But the question is that now matter how good of a ground and arresters you have you are still vaurnable to a strike, correct? I was going to ground each leg of the tower to a 8' ground rod. will this be enough, along with a lightning arrester? I would like to have this station up all the time instead of putting it up in the fall when lightning is slim and taking it down when storm season arrives. My next idea was to get a wilson 5000 and put it up on a push pole outside the attic window and extend it above the roof and put it up when ever I needed, Is this a good idea, and will the performance be the same as if I were running the Imax 2000? Thanks for any information! How in the heck did they do it back in the day with just strapping it to the chimney and calling it good? The Solarcon IMax-2000 antenna when hit with lightning will literally explode. I know because that is what mine did when it was hit by lightning. It looked like someone put an M-80 inside the bottom of the antenna and lit it. All that was left of the top fibreglass whip was a few long strands of fibreglass threads. Mine was up at about 85 feet in the air at the base of the antenna in the top of a very tall pine tree. Boom! Fortunately the coax was unhooked from the radio and away from the house when the antenna was stuck. Night Ranger
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 5, 2016 13:29:39 GMT -5
I been wanting to put up a base antenna now for awhile, I will admit that Iam afraid of lightning! Who isnt? Last fall I bought a new Imax 2000 and put the base at 20' off the ground, attached to 2 pieces of 10'Pipe strapped to my porch post. I took it down in april when the storm season started. It worked great swr was flat and I talked all over that winter. My goal was to put up my 40' tower I have had in the shed now for 4 yrs, and fly the Imax on top of that!! That thing would rock right? But the question is that now matter how good of a ground and arresters you have you are still vaurnable to a strike, correct? I was going to ground each leg of the tower to a 8' ground rod. will this be enough, along with a lightning arrester? I would like to have this station up all the time instead of putting it up in the fall when lightning is slim and taking it down when storm season arrives. My next idea was to get a wilson 5000 and put it up on a push pole outside the attic window and extend it above the roof and put it up when ever I needed, Is this a good idea, and will the performance be the same as if I were running the Imax 2000? Thanks for any information! How in the heck did they do it back in the day with just strapping it to the chimney and calling it good? The Solarcon IMax-2000 antenna when hit with lightning will literally explode. I know, because that is what mine did when it was hit by lightning. It looked like someone put an M-80 inside the bottom of the antenna and lit it. All that was left of the top fibreglass whip was a few long strands of fibreglass threads. Mine was up at about 85 feet in the air at the base of the antenna in the top of a very tall pine tree. Boom! Fortunately the coax was unhooked from the radio and away from the house when the antenna was stuck. Night Ranger That's true of any fiberglass antenna. I've seen Big Sticks, A99's and even our 220 Mhz repeater antenna get blown to splinters from lightning strikes. On the other hand, I've seen 70's vintage metal 5/8 wave ground planes with coil matching networks where the lightning will vaporize the matching network, even though the metal parts of the antenna survived. The only omni antennas that can survive lightning are those which have heavy duty gamma matching, or no matching at all (like a direct fed 1/4 wave, Starduster, or Astroplane).
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Post by 2600 on Mar 5, 2016 22:27:15 GMT -5
Simple rule:
"Height is Might".
73
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Post by whitetail on Mar 7, 2016 20:26:08 GMT -5
So what you are saying at the 36' height or higher will give me the lowest angle of radiation toward the horizon? What does this mean? So reading down your post, you say (the higher you go, the further your signal will travel to the horizon) this is what you want, correct? Sorry for asking but I dont follow you on this. What do you mean traveling to the horizon? I plan on doing an rf choke or loop at the bottom of the feedpoint of my antenna, so hopefully this should keep stray rf currents out. I may run the Imax for a year to see how it performs up there, then I might put up a sirio gain master, Iam reading up on those as well, (any info you have please share). Ultimately I just want a my station to be setup right the 1st time. And if higher is not good I can leave a section of tower off and bee in the 30'-36' range. Will 15' taller make a difference with the 36 rule, how much? My goal was 45'-50' if thats not doable or will hurt my signal Like I said I can leave a section off. Thanks for helping me understand this. The pic's below illustrate a typical antenna radiation pattern in the vertical plane (Looking at it from the side). For local communication (and really long distance F layer DX), you want your signal heading out as close to flat as possible as the first image illustrates. Operating the antenna at a lower than 36' height, or without the proper radial counterpoise, will raise the angle of those RF lobes as shown in the second image. This might be desirable for shorter E-layer skip, but when you are talking local, you are wasting your signal, by aiming for the clouds, when you want your signal to reach places at ground level. Don't sweat the minor details though. There is no cast in stone "sweet spot" rule when it comes to antenna height. Yes, there are optimal heights for specific types of skip conditions. I know hams with motorized tower winches, who can raise and lower their antennas to optimize the received signal level based on where the signals are coming from. But that is way more trouble than is needed for the average radio op. Put your antenna up as high as you can practically do. Thanks sandbagger, That helps me understand better what is going on now. Iam going to go with my orig plan and put up the entire tower and see how it works out for me.
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Post by whitetail on Mar 7, 2016 20:36:38 GMT -5
I you plan on running anything bigger than a (3) pill amplifier, I would look carefully at the Gain Master wattage specs. Sirio Gain-Master Hi-Tech Fiberglass 10m & CB Base Antenna: Max Power 500 Watts (CW) continuous, 1000 Watts (CW) short time. There is talk that Sirio will be releasing a shorter version of this antenna to be marketed as the Gain Master HW ("Half Wave" not High Wattage) Solarcon I-Maxx 2000:2000 watts (CW) short time power handling. No (CW) continuous rating given. (I have seen where it was published that it has been tested to 5000 watts short term, but doubt that claim. PL connector inserts start to melt at that RF power level) Both antennas are constructed of non-conductive fiberglass which is safer if the antenna topples in the proximity of overhead high voltage power lines. I run a Sirio 2016 and a home made ugly balun under it with great success at 36' above grade: Omni-directional, high power handling capability Low radiation angle Multi element ground plane (with 16 solid aluminum rods) Protection from static discharges (Capacitor Hat on top) Transformer DC-ground Base Connector: UHF-female directly under the large diameter base plate (shielded somewhat from direct rain) Made of aluminum alloy 6063 T-832 Type: 5/8 ground plane Frequency range: tune-able from 26.4 to 28.2 MHz Max. power: 1000 Watts (CW) continuous 3000 Watts (CW) short time www.sirioantenna.com/index.php?main_page=product_info&cPath=2_18&products_id=184&zenid=b7ad6ccb0c6be1de0c538652fe92b6feI dont think the gainmaster is going to get it for me. Those numbers wont cut it, What other antenna on the market can handle at least 1,500 watts? I hear the siro 2016 is a great antenna, glad to hear you have good success with it.
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Post by whitetail on Mar 7, 2016 20:44:35 GMT -5
I been wanting to put up a base antenna now for awhile, I will admit that Iam afraid of lightning! Who isnt? Last fall I bought a new Imax 2000 and put the base at 20' off the ground, attached to 2 pieces of 10'Pipe strapped to my porch post. I took it down in april when the storm season started. It worked great swr was flat and I talked all over that winter. My goal was to put up my 40' tower I have had in the shed now for 4 yrs, and fly the Imax on top of that!! That thing would rock right? But the question is that now matter how good of a ground and arresters you have you are still vaurnable to a strike, correct? I was going to ground each leg of the tower to a 8' ground rod. will this be enough, along with a lightning arrester? I would like to have this station up all the time instead of putting it up in the fall when lightning is slim and taking it down when storm season arrives. My next idea was to get a wilson 5000 and put it up on a push pole outside the attic window and extend it above the roof and put it up when ever I needed, Is this a good idea, and will the performance be the same as if I were running the Imax 2000? Thanks for any information! How in the heck did they do it back in the day with just strapping it to the chimney and calling it good? The Solarcon IMax-2000 antenna when hit with lightning will literally explode. I know, because that is what mine did when it was hit by lightning. It looked like someone put an M-80 inside the bottom of the antenna and lit it. All that was left of the top fibreglass whip was a few long strands of fibreglass threads. Mine was up at about 85 feet in the air at the base of the antenna in the top of a very tall pine tree. Boom! Fortunately the coax was unhooked from the radio and away from the house when the antenna was stuck. Night Ranger I had a a99 back in the day and it got hit by lightning and it blew it apart. the bottom looked like a bent wilting tree. lucky you had the coax unplugged! Iam hoping my project will be done by july. I hope to catch you on the air waves this year like I did last summer for the roundup.
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Post by cbrown on Mar 9, 2016 9:46:24 GMT -5
I dont think the gainmaster is going to get it for me. Those numbers wont cut it, What other antenna on the market can handle at least 1,500 watts? I hear the siro 2016 is a great antenna, glad to hear you have good success with it. Hygain SPT-500 claims 1,500 watts. www.hy-gain.com/Product.php?productid=SPT-500
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Post by whitetail on Mar 10, 2016 20:23:56 GMT -5
I dont think the gainmaster is going to get it for me. Those numbers wont cut it, What other antenna on the market can handle at least 1,500 watts? I hear the siro 2016 is a great antenna, glad to hear you have good success with it. Hygain SPT-500 claims 1,500 watts. www.hy-gain.com/Product.php?productid=SPT-500I looked at this antenna with the site you provided, along with Dx engineering. I like the antenna, I couldnt find out how many sections this beast is, could you help? Also where it says DB gain in the Specifications it says 5.3, what is this number referring to? (say compaired to my Imax 2000) If it is a better antenna then the Imax I may go for it, how much better is the question? I see in the description it says antenna is illegal for 11 Meters use. That must mean it is good, because they dont want you to use it. Any help or reviews will be of big help.
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Post by Night Ranger on Mar 10, 2016 21:12:42 GMT -5
I looked at this antenna with the site you provided, along with Dx engineering. I like the antenna, I couldnt find out how many sections this beast is, could you help? Also where it says DB gain in the Specifications it says 5.3, what is this number referring to? (say compaired to my Imax 2000) If it is a better antenna then the Imax I may go for it, how much better is the question? I see in the description it says antenna is illegal for 11 Meters use. That must mean it is good, because they dont want you to use it. Any help or reviews will be of big help. The Hy-Gain Super Penetrator 500 is about as good as it gets. Night Ranger
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 10, 2016 21:34:53 GMT -5
I looked at this antenna with the site you provided, along with Dx engineering. I like the antenna, I couldnt find out how many sections this beast is, could you help? Also where it says DB gain in the Specifications it says 5.3, what is this number referring to? (say compaired to my Imax 2000) If it is a better antenna then the Imax I may go for it, how much better is the question? I see in the description it says antenna is illegal for 11 Meters use. That must mean it is good, because they dont want you to use it. Any help or reviews will be of big help. That SPT-500 antenna is probably the best commercially made CB ground plane antenna made. The only thing that might edge it out in gain, would be the Interceptor 10K, but that is custom built, very expensive, and may no longer be in production, last I heard.......
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Post by cbrown on Mar 11, 2016 16:40:35 GMT -5
That SPT-500 antenna is probably the best commercially made CB ground plane antenna made. The only thing that might edge it out in gain, would be the Interceptor 10K, but that is custom built, very expensive, and may no longer be in production, last I heard....... They might be back. I last visited the site a few weeks ago and they said they were taking orders again. We'll see. One thing I like about the I-10K is the 1.3 MHz bandwith.
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Post by whitetail on Mar 24, 2016 8:16:49 GMT -5
I think Iam going to give the Hy-Gain Super Penetrator 500 a try. After hearing your input on these, I got to try one. What is leading me towards it is the gain in receive, it has over the Imax 2000. All the videos & comments I found on the web everyone says that they were the best antennas made. I am courious of how you tune it for 11 meters. Also I will be using freeband freq's on band C, 26.515 - 26.995, & Band E, 27.415 - 27.855. Not all the these channels will be used, just channels slightly below the normal 40, and above the normal 40. So what is the best way to possibly tune this antenna to accomidate most of these channels, and still have a good solid SWR? Thanks.
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Post by cbrown on Mar 24, 2016 9:27:03 GMT -5
Pick the lowest frequency you'll use, them pick the highest. Find the middle frequency between the two and tune the antenna to that.
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Post by whitetail on Mar 25, 2016 7:19:23 GMT -5
Pick the lowest frequency you'll use, them pick the highest. Find the middle frequency between the two and tune the antenna to that. Could you give me a little bit more help on this. I always tuned my antenna's base and mobile the following way. I always use an external meter when testing, I would calibrate the meter, then check the reading on ch 40 and then on ch 1, then if they read different I adjust the antenna to the lower setting, when all tuned up I get an equal reading on both channels 1 & 40. The question is though is how do I tune to the middle of the band, when only using one reading from that frequency? What do you do from there? Thanks.
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Post by cbrown on Mar 25, 2016 12:26:58 GMT -5
SWR basically works in a curve; when you tune it flat for one frequency, as you either increase or decrease frequency the SWR will start to rise. The CB band is 26.965 MHz to 27.405 MHz, so the center frequency you'd want to tune your antenna to is 27.185 MHz(CH 19) so that your SWR would rise equally as you travel up and down the dial and could use all the channels. Depending on how broad-banded your antenna is, you might not be able to use it for the frequency range you had mentioned (26.515 to 27.855 MHz). My base antenna for 11M is an I-10K Interceptor, which can be adjusted to operate with a 1.4 MHz bandwidth before I exceed a 2.0 SWR. So, using 27.185 MHz (CH 19) as a center frequency, I can use my antenna from 26.485 MHz to 27.885 MHz with an SWR curve that does not exceed 2.0 on either end. An SWR mere will work fine, but I recommend using an antenna analyzer. Still confused? I might have not explained it clearly enough. Let me know and I'll try again.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Mar 25, 2016 12:35:14 GMT -5
Pick the lowest frequency you'll use, them pick the highest. Find the middle frequency between the two and tune the antenna to that. Could you give me a little bit more help on this. I always tuned my antenna's base and mobile the following way. I always use an external meter when testing, I would calibrate the meter, then check the reading on ch 40 and then on ch 1, then if they read different I adjust the antenna to the lower setting, when all tuned up I get an equal reading on both channels 1 & 40. The question is though is how do I tune to the middle of the band, when only using one reading from that frequency? What do you do from there? Thanks. Any antenna has a limited bandwidth, so they are designed and cut for the frequency range that it's intended for. But it's not an exact science, so there is usually a little bit of tuning that needs to be done to zero in the lowest SWR on the channels you use. Naturally, if you intend to run a range between 26.5 and 27.8, it's a bit wider bandwidth than simply tuning between channel 1 through 40. Depending on the design, the antenna may not cover all of that range with a less than 2:1 SWR. But the tuning method will still be the same. You take your highest channel, your lowest channel, and your middle channel. Check SWR on the highest, middle, and the lowest channels. If SWR is higher on the higher channel, better on the middle channel, and lowest on the lower channel, then the antenna needs to be shortened. Conversely, if the match is better on the highest channel, then the antenna needs to be lengthened. Ideally, you will want your best SWR on the middle channel, with an even rise on the highest and lowest channel. And antenna that presents a 1.1:1 SWR on the middle channel, and a less than 2:1 SWR on the upper and lower channels is properly tuned.
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Post by whitetail on Mar 25, 2016 23:28:34 GMT -5
Thanks cbrown & sandbagger. I understand it better now, Trying to get all the information I can now and study it so when it come time to adjust and tune on the tower I know what to do.
Cbrown, how do you like your I-10K Interceptor base antenna? How long did you have it in service for? What are some results you gotten with this antenna? Iam back and forth now on which one to get. I do see that the Interceptor does not have a top hat. Having the top hat reduces white noise in the receive. Do you get alot of background noise talking to stations that only give you 1-4 sunits on the meter? I do with my Imax 2000, This is what Iam trying to elimminate. Thanks.
defination for CB,
Constantly Buying
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Post by 2600 on Mar 25, 2016 23:54:56 GMT -5
I suspect that the phenomenon of the exploding Antron has more to do with the rainwater that's generally trapped inside of one that's been outside for more than one winter. Explosive conversion of water to steam is what I think is happening.
Every Antron or similar antenna I have seen taken down had water seeping out of it, seems like. You would think that if the water can get in that easily there would be a way for it to drain out as a part of the design. But it just accumulates in there with nowhere to go.
73
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Post by cbrown on Mar 29, 2016 9:43:43 GMT -5
I put up my Interceptor 10-K back in 2004, it's been in service ever since. I like it, works very well for me. And mine has a top hat; I believe all of them did. But if I were to replace it, I would be tempted to use the Hygain SPT-500 myself.
Price-wise, it's probably your best bet. Another option is the Zero Five 5K Colossal 5/8 wave, which is $299. Mr. Coily have the .64 wave Excalibur antenna, but he's looking for $500.
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Post by whitetail on Apr 4, 2016 19:49:02 GMT -5
I put up my Interceptor 10-K back in 2004, it's been in service ever since. I like it, works very well for me. And mine has a top hat; I believe all of them did. But if I were to replace it, I would be tempted to use the Hygain SPT-500 myself. Price-wise, it's probably your best bet. Another option is the Zero Five 5K Colossal 5/8 wave, which is $299. Mr. Coily have the .64 wave Excalibur antenna, but he's looking for $500. Thanks brown, I an just seeing what is out there and what works good. I think I may purchase the spt 500, but I got alot of work to do in the meantime. Breaking ground for the tower here in a few weeks.
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Post by cbrown on Apr 6, 2016 15:25:43 GMT -5
Good luck! Ask if you have any questions.
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Post by thehobo on Apr 7, 2016 10:23:55 GMT -5
say hey whitetail, something to look at.. the antenna your looking at is good to 1500 pep??? you mite look some more as if in the future you want a bigger amp, but your limited to the 1500 watts on the one you have up, and your going to go to a 100 foot tower, well if one puts 2 and 2 together, thats alot of climbing to change out antennas.. give it some more thinking as to were you mite be in a year or so down the road?? as alot of cbers no, the antenna is usually the make or break point of ones set up.. just putting a word in in case... a freind from kittanning pa.. were i was raised..
thehobo 269150 am monitor ch..
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Post by cbrown on Apr 8, 2016 9:09:20 GMT -5
Thehobo brings up a good point, too. The antenna is really the make or break part of your setup, so putting up the best antenna you can pays off in the long run. Also using a high quality coaxial cable is a good idea, too. On my base setup I run LMR-400. I prefer the double shielding Times Microwave offers, it helps keep the RF interference down, too.
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Post by whitetail on Apr 14, 2016 20:05:28 GMT -5
Well I am breaking ground tomorrow for the tower! Some last minute thoughts. Iam just wondering if I should go bigger on the foundation. The base plate of the tower is 15"x15" square, I was going to make it 30"x30" inches square. If I place the base plate right in the center of the 30x30 that gives me aprox 7" of foundation sticking out of all sides of the bottom plate. I feel that this is maybe not enough. Maybe I should go 36x36 square and 4 1/2' deep. If I go 36" square that will give me aprox 10" of foundation sticking out of all sides of the bottom plate. Will this be enough to support the tower? I Just want to do it right the 1st time, overkill is better then not enough. The bottom of the hole will have rods driven in at least 3' below that and sticking up so the cage can be attached. What are your thoughts??
I am getting 3 more sections of tower from a camp owner that no longer needs it, I may want to put all this up someday, so thinking ahead to compensate for that in the future!
Tower 40' high with Imax 2000 or a 500.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Apr 14, 2016 21:19:49 GMT -5
Well I am breaking ground tomorrow for the tower! Some last minute thoughts. Iam just wondering if I should go bigger on the foundation. The base plate of the tower is 15"x15" square, I was going to make it 30"x30" inches square. If I place the base plate right in the center of the 30x30 that gives me aprox 7" of foundation sticking out of all sides of the bottom plate. I feel that this is maybe not enough. Maybe I should go 36x36 square and 4 1/2' deep. If I go 36" square that will give me aprox 10" of foundation sticking out of all sides of the bottom plate. Will this be enough to support the tower? I Just want to do it right the 1st time, overkill is better then not enough. The bottom of the hole will have rods driven in at least 3' below that and sticking up so the cage can be attached. What are your thoughts?? I am getting 3 more sections of tower from a camp owner that no longer needs it, I may want to put all this up someday, so thinking ahead to compensate for that in the future! Tower 40' high with Imax 2000 or a 500. Well it all depends on whether the tower is free standing, attached to another structure, or guyed. If free standing, I'd go 4'X 4' X 4'. If attached to another structure or guyed, you could get away with 3 X 3 X 3. Also, you have to consider what you might want to put on there in the future. A simple IMax antenna is only marginally more wind resistance than the tower itself. But if someday, you decide you want a 5 element beam up there, the wind resistance is going to get ugly if the tower isn't supported well enough.
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