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It is a truism
It is a truism that short antennae are poor inefficient radiators, and no
amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. |
It is a truism
gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no How short is a "short antenna"? What is the metric for a "poor inefficient radiator"? Without numbers all you have is arm waving. -- Jim Pennino |
It is a truism
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It is a truism
On 11/12/2014 1:50 PM, gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. |
It is a truism
FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 -- Jim Pennino |
It is a truism
El 13-11-14 21:39, FBMboomer escribió:
On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. I agree that in many practical circumstances electrically small antennas do not perform well. I also know that having an antanna is better than nothing. The smaller the antenna, the more difficulties you will experience to get radiation out of it (heat radiation doesn't count). In free space you can make a rather efficient antenna with say maximum size of 0.03lambda, as long as you are a good electron tamer. If not, electrons escape from the structure showing a nice corona, or full breakdown occurs. Examples are tuned loops and short dipoles with capacitive end plates and series inductors to arrive at some nice impedance. Tuning in the shack with lots of cable and a bad ferrite balun between tuner and antenne mostly results in good VSWR but low efficiency (as many people know). In real world even a very small very efficient antenna may not perform as expected Close to the antenna (say within 0.1 lambda), reactive fields are very strong and they increase rapidly when reducing the distance. This is also valid for "magnetic loops" (that Jennings HV vacuum capacitor or thick potato cutter/slicer is for a reason). When you put such a nice small antenna close to lossy dielectric (building materials, ground, etc), significant part of the RF power may be dissipated in that lossy dielectric materials. In case of short monopoles, lots of power is mostly dissipated in the ground/counterpoise system (saline wetlands, sea and large metallic surfaces excepted). Of course we can solve this with lots of burried radials, or somewhat less elevated radials, but such solutions don't qualify for an electrically small antenna anymore. -- Wim PA3DJS Please remove abc first in case of PM |
But most people do not have access to tower that can get their dipole antenna 100' off the ground for 75 meters!
The G5RV was designed to work on 20 meters. The ladder line is the matching network. It does not perform well on 10 or 40 meters. That usually has something to do with a cut dipole not working well on anything that is the first harmonic. A portion of this planet is inhabited by morons that does not know that and that picks their antenna by price rather than by performance! My inverted V - 80M off center fed dipole antenna is only 30' off the ground in the middle and maybe 20' off the ground on the ends. It is fed with about 60' of LMR 400 and I can converse with anyone that I can hear. Most of the people I hear are using 600 - 1200 watt amplifiers and some other type of dipole antenna, and although their signal is louder than mine, my audio is much cleaner then theirs! To me - amplifiers are for CB'rs that are hard of hearing and thinks that you cannot carry on a conversation unless you are 20/9! When I become a O&O - the first thing I am going to do is send each and every one of those people a pink slip and have them explain why they use more power than necessary. I would keep on sending them pink slips until they either get the message - that the reason for the signal report is so you can adjust your power to the minimum amount necessary to carry on the conversation, or until the ARRL / FCC gets tired of it and sends them a greetings to come and see them and explain why they can't follow the rules! As far as these people bragging about how they pick on those that are on a G5RV - I would gladly send them pink slips also - until they reduce their power or answer for their actions in front of a FCC examiner... I would love to see how many of these people could still pass a General Class Examination and how many of them bought their license and will let it drop - if they are asked to retest... |
It is a truism
On Thursday, November 13, 2014 2:38:40 PM UTC-6, FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. But again, as everyone has pointed out, it's not the radiator, it's the feed system that provides the losses. The *usual* G5RV is generally lousy compared to a coax fed 1/2 dipole because of the funky poorly designed feed system, not the radiator. IE: coax to a choke balun to twin lead to the radiator. That's a joke.. The feed system is the culprit, not the slightly shortened radiator. Which BTW, is not really all that short, as far as short antennas go. It's more like a reduced size radiator, rather than actually short like say a short mobile antenna, or a very small dipole. If you can feed a 102 ft dipole with nothing but twin lead, the antenna system is quite efficient. Say if you use Cecil Moore's method of feeding a G5RV with ladder line. You are blaming the wrong culprit, same as Gareth continues to do. You have to consider the whole antenna *system*, not just the radiator. Only the *very* short radiators suffer from ohmic losses. The 102 ft dipole used with a G5RV does not qualify in that regard. Most all the loss is in the feed system, not the radiator itself. And that can be corrected to be pretty much a non issue. |
It is a truism
On Thursday, November 13, 2014 10:13:02 PM UTC-6, Channel Jumper wrote:
But most people do not have access to tower that can get their dipole antenna 100' off the ground for 75 meters! I actually want my 80 meter antennas to shoot straight up. I'm working NVIS paths 98 percent of the time. Only the DX'ers need a high dipole. Or a good vertical, which generally is better. When I become a O&O - the first thing I am going to do is send each and every one of those people a pink slip and have them explain why they use more power than necessary. Knock yourself out. You will only succeed in looking like a jackass, and the FCC could care less as long as they don't exceed the legal limit or cause splatter due to an underloaded amp, etc. |
It is a truism
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It is a truism
Rob wrote:
wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. But that is actually very useful on the low bands! Not for working "DX", but when you want to run a roudtable in an area it works very well, especially when not in full summer daylight. There are several of these groups active here, and it provides a convenient coverage area for our language area, much larger than what you achieve on e.g. 2 meters with typical vertical omni antennas mounted on rooftops. Yes, if what you want to achieve is local area coverage on HF, then NVIS antennas work well for that. The real problem is people throw around terms like "crappy", "sucks", and "poor performer" without defining what it is they are trying to achieve. -- Jim Pennino |
It is a truism
Jerry Stuckle wrote:
On 11/13/2014 6:12 PM, wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) False logic. You don't know how many people with good signals are using G5RV's, because you only ask those with poor signals. Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Yes and no. Depending on their design, short antennas can be very efficient. See http://www.futurity.org/radio-wave-c...phones-801322/ for an example. But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. -- Jim Pennino |
It is a truism
wrote in message ... But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. At a given height wouldn't all simple horizontal antennas (halfwave dipole, g5rv) have the same take off angle and be equal in that respect ? Say you had a halfwave horizontal and replaced it with the g5rv at the same height there shold not be any differance it the takeoff angle. If there is any big differance in the signal , it would probably be the loss in the feedline going to the 102 foot long antenna. I have been tempted to put up a g5rv just to see what it would do. I have an 80 meter dipole and also an OCF Carolina Windom at about the same heigth. They are around 60 feet on the ends. There is usually not too much differance in them except certain directions and distances. Then there can be several S units at some directions. This is probably because they are at right angles to each other. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
It is a truism
Ralph Mowery wrote:
wrote in message ... But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. At a given height wouldn't all simple horizontal antennas (halfwave dipole, g5rv) have the same take off angle and be equal in that respect ? Say you had a halfwave horizontal and replaced it with the g5rv at the same height there shold not be any differance it the takeoff angle. If there is any big differance in the signal , it would probably be the loss in the feedline going to the 102 foot long antenna. Yes. It also, in general, applies to yagi antennas, though the numbers are a bit different. I have been tempted to put up a g5rv just to see what it would do. I have an 80 meter dipole and also an OCF Carolina Windom at about the same heigth. They are around 60 feet on the ends. There is usually not too much differance in them except certain directions and distances. Then there can be several S units at some directions. This is probably because they are at right angles to each other. Probably true. -- Jim Pennino |
It is a truism
On 11/14/2014 12:34 PM, wrote:
Jerry Stuckle wrote: On 11/13/2014 6:12 PM, wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) False logic. You don't know how many people with good signals are using G5RV's, because you only ask those with poor signals. Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Yes and no. Depending on their design, short antennas can be very efficient. See http://www.futurity.org/radio-wave-c...phones-801322/ for an example. But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
"Jerry Stuckle" wrote in message ... On 11/14/2014 12:34 PM, wrote: You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Antennas 'always' work as predicted. People just don't always factor in everything in the prediction. Just as I worked a station on 432 MHz with 25 watts to a 1/4 wave ground plane that was about 1000 miles away. Nice bit of tropo that day. I bet I could put up a g5rv at 30 feet on some rare country and get loads of 5/9 signals no mater how many times the calls had to be repeatd. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
It is a truism
El 14-11-14 19:12, Ralph Mowery escribió:
wrote in message ... But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. At a given height wouldn't all simple horizontal antennas (halfwave dipole, g5rv) have the same take off angle and be equal in that respect ? Say you had a halfwave horizontal and replaced it with the g5rv at the same height there shold not be any differance it the takeoff angle. If there is any big differance in the signal , it would probably be the loss in the feedline going to the 102 foot long antenna. You are right, if you use a G5RV that has no feedline radiation (both ladder line and coaxial part), the shape of the H-plane elevation pattern is the same, and practically the same for the E-field plane. I have been tempted to put up a g5rv just to see what it would do. I have an 80 meter dipole and also an OCF Carolina Windom at about the same heigth. They are around 60 feet on the ends. There is usually not too much differance in them except certain directions and distances. Then there can be several S units at some directions. This is probably because they are at right angles to each other. The shape of the radiation pattern for an OCF (no feed line radiation) at greater then twice the half wave frequency is different from that of a originally center-fed half wave dipole. The current distribution is different (you get phase reversals in the OCF antenna). Just an example: When using an OCF at twice the half wave frequency, it has no radiation in the H-plane (that is the plane perpendicular to the wires, you get a 4-leaf pattern). A center-fed antenne has good radiation in the H-plane at twice the half wave frequency. Of course it has high input impedance, so one has to take care of the matching. That means that if you have an OCF with its half wave frequency at 75m, it will not act as a good NVIS antenna at 40m. -- Wim PA3DJS Please remove abc first in case of PM |
It is a truism
Jerry Stuckle wrote:
On 11/14/2014 12:34 PM, wrote: Jerry Stuckle wrote: On 11/13/2014 6:12 PM, wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) False logic. You don't know how many people with good signals are using G5RV's, because you only ask those with poor signals. Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Yes and no. Depending on their design, short antennas can be very efficient. See http://www.futurity.org/radio-wave-c...phones-801322/ for an example. But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Big whoop. The post wasn't about how many QSL cards have been collected, it was about antenna patterns. Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Any prediction is as good as the model used to make the prediction. If one can not build a model that is accurate to about two digit accuracy, then they shouldn't be trying to build models. -- Jim Pennino |
It is a truism
On 11/14/2014 3:49 PM, Ralph Mowery wrote:
"Jerry Stuckle" wrote in message ... On 11/14/2014 12:34 PM, wrote: You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Antennas 'always' work as predicted. People just don't always factor in everything in the prediction. Just as I worked a station on 432 MHz with 25 watts to a 1/4 wave ground plane that was about 1000 miles away. Nice bit of tropo that day. The problem is - taking into consideration EVERYTHING which could affect it. Well nigh impossible - even the neighbor's chain link fence could have an effect, for instance. That's why AM commercial radio stations plan their antenna phasing for the desired pattern - but then have to measure it almost always tweak the delay lines to get the exact shape they want. For instance - I remember one I worked at back in the 70's. It's pattern was directly affected by moisture in the air and, to a certain effect, ground. You could see the difference in tuning for the transmitters between a very foggy night and a clear one. This also caused a change in the radiated pattern. Fortunately it was still with the limits set by the FCC, or we'd have to rephase the towers with every change to the weather. BTW - the main cause was the ground plane (circles of wires around each tower with radials from the tower out - and silver soldered where ever the wires crossed) was pretty old, and subject to changing weather conditions. I bet I could put up a g5rv at 30 feet on some rare country and get loads of 5/9 signals no mater how many times the calls had to be repeatd. I highly suspect you could! :) --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
On 11/14/2014 3:55 PM, wrote:
Jerry Stuckle wrote: On 11/14/2014 12:34 PM, wrote: Jerry Stuckle wrote: On 11/13/2014 6:12 PM, wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) False logic. You don't know how many people with good signals are using G5RV's, because you only ask those with poor signals. Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Yes and no. Depending on their design, short antennas can be very efficient. See http://www.futurity.org/radio-wave-c...phones-801322/ for an example. But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. For a dipole over average ground: Height Gain @ Elevation lambda 0.1 3.89 90 0.15 5.55 90 0.2 5.95 90 0.25 5.81 62 0.3 5.80 48 0.35 6.00 40 0.4 6.38 35 0.45 6.86 31 0.5 7.41 28 0.55 7.76 25 0.6 7.87 23 0.65 7.76 21 0.7 7.54 20 0.75 7.30 18 0.8 7.16 17 0.85 7.15 16 0.9 7.26 15 0.95 7.47 15 1 7.71 14 At 75M .4 lambda is about 100 feet. Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Now is you happen to be in a salt water marsh surrounded by 100 foot tall steel blimp hangers, your results may vary. You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Big whoop. The post wasn't about how many QSL cards have been collected, it was about antenna patterns. And I wouldn't have gotten that coverage with an antenna that was "crap". Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Any prediction is as good as the model used to make the prediction. If one can not build a model that is accurate to about two digit accuracy, then they shouldn't be trying to build models. Then tell my why my antenna regularly had a solid signal if it was "crap"? And BTW - I suspect the vast majority of hams on 80 meters have antennas much lower than your claimed 100' - yet they get out quite well. So much for your "crap". Theory is fine - but only as far as you can apply it to the real world. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
Jerry Stuckle wrote:
On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". I posted the NUMBERS for an AVERAGE situation. If you wish to disucss "crap", then first define "crap" in numbers. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Big whoop. The post wasn't about how many QSL cards have been collected, it was about antenna patterns. And I wouldn't have gotten that coverage with an antenna that was "crap". Again, I never said anything was "crap"; that is your word and has no meaning until defined. Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Any prediction is as good as the model used to make the prediction. If one can not build a model that is accurate to about two digit accuracy, then they shouldn't be trying to build models. Then tell my why my antenna regularly had a solid signal if it was "crap"? And BTW - I suspect the vast majority of hams on 80 meters have antennas much lower than your claimed 100' - yet they get out quite well. You really do not undertand things like "optimal", do you? And once again, I never said anything was "crap"; that is your word and has no meaning until defined. So much for your "crap". Theory is fine - but only as far as you can apply it to the real world. Most people do not have a problem with applying theory to the real world, but apparently you do. I couldn't care less. And once again, I never said anything was "crap"; that is your word and has no meaning until defined. -- Jim Pennino |
It is a truism
On Friday, November 14, 2014 11:46:03 AM UTC-6,
Generally for DX a takeoff angle of 30 degrees or less is the rule of thumb for best general performance. Of course the antenna still "works" at other heights, but if DX is what you want to achieve, then best results, on the average over average ground, the antenna will work best for that at a height of .5 lambda or better. Yep, for 80m, it's usually easier to put up a good vertical for dx than a high dipole. And even then sometimes the vertical will do the best. W8JI talks a lot about this comparing his 160m verticals and his high 160m dipoles. Most times, his verticals still win to long paths. I forgot how high his dipole was, but it's pretty high vs what most people have. People talk about short antennas being poor radiators, but on 40m with my appx 40 ft tall full size dipole fed with coax, my mobile antenna would beat it most every night from Houston to Jacksonville FL. I thought maybe it was a fluke, but I tested it a few more times, and it almost always won. So the most efficient antenna does not always win the race if the less efficient antenna puts more rf at the lower angles where you want for longer paths, vs the highly efficient antenna like my coax fed dipoles. At 40 ft on 40m, it's still shooting a lot of rf at fairly high angles, and not so much at the low angles. Less than my mobile antenna did. I remember one night I was at the coast fishing, and I actually ran a wide braid ground wire from the truck body into the ocean just to add that extra gusto. On longer paths, I was smoking some people using dipoles and running amps vs my extended 14 ft tall mobile antenna sitting on the beach with 100w. So much for small antennas always being poor radiators.. :/ Efficiency isn't always everything. But it usually is for NVIS paths, which is why I've always preferred coax fed dipoles for my usual 75m NVIS chatter. |
It is a truism
On 11/14/2014 4:26 PM, wrote:
Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." I posted the NUMBERS for an AVERAGE situation. And claimed the numbers as an absolute. If you wish to disucss "crap", then first define "crap" in numbers. If you wish to discus "suck", then first define "suck" in numbers. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Big whoop. The post wasn't about how many QSL cards have been collected, it was about antenna patterns. And I wouldn't have gotten that coverage with an antenna that was "crap". Again, I never said anything was "crap"; that is your word and has no meaning until defined. You did say "suck" for any dipole under 60' - I can pull up the post (in another thread) if you wish - but you already denied you said it in that thread, despite the direct quite. Here you said it would "suck". That is YOUR word and has no meaning until defined. Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Any prediction is as good as the model used to make the prediction. If one can not build a model that is accurate to about two digit accuracy, then they shouldn't be trying to build models. Then tell my why my antenna regularly had a solid signal if it was "crap"? And BTW - I suspect the vast majority of hams on 80 meters have antennas much lower than your claimed 100' - yet they get out quite well. You really do not undertand things like "optimal", do you? You really do not understand things like "suck", to you? And once again, I never said anything was "crap"; that is your word and has no meaning until defined. Not in this thread - but you did in another thread. Here you said "suck". So much for your "crap". Theory is fine - but only as far as you can apply it to the real world. Most people do not have a problem with applying theory to the real world, but apparently you do. I couldn't care less. Yes, you really do have a problem with mixing theory and real world. And once again, I never said anything was "crap"; that is your word and has no meaning until defined. Once again, you didn't say "crap" in this thread - you said "suck". But you DID say "crap" in another thread. Do I need to paste THAT quote, also? Until you can prove your "crap" and "suck" theories, you are full of "crap" and your theories "suck". And don't try to quote ideal situations. Look at the REAL WORLD. You neglect that the vast majority of people on 80 meters (including me) use antennas which are less than 100' above the ground - yet we work the band quite well. And our signals are not "crap", nor do they "suck". Now if YOU have a problem with an 80 meter antenna, that's YOUR problem. Not the rest of the world's. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
Jerry Stuckle wrote:
On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. I posted the NUMBERS for an AVERAGE situation. And claimed the numbers as an absolute. I never made any such claim. snip remaining repetitive puerile drivel -- Jim Pennino |
It is a truism
On 11/14/2014 10:02 PM, wrote:
Jerry Stuckle wrote: On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. It is still your statement. I posted the NUMBERS for an AVERAGE situation. And claimed the numbers as an absolute. I never made any such claim. snip remaining repetitive puerile drivel Your claim was that such antennas suck. Period. No qualifications. That is the definition of an absolute. But you're never wrong, are you? Even when presented with the facts. You just try to weasel out of it and/or ignore other applicable comments. Shows you for your true colors. All hot air but no understanding. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
Jerry Stuckle wrote:
On 11/14/2014 10:02 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. It is still your statement. It was the posters statement and my response to that statement. snip remaining puerile drivel -- Jim Pennino |
It is a truism
On 11/15/2014 12:58 PM, wrote:
Jerry Stuckle wrote: On 11/14/2014 10:02 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. It is still your statement. It was the posters statement and my response to that statement. snip remaining puerile drivel Wrong again, as the archives prove. And you can't lie your way out of it. You can copy and paste. But you do not UNDERSTAND. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
On Saturday, November 15, 2014 12:40:29 PM UTC-6, Jerry Stuckle wrote:
On 11/15/2014 12:58 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 10:02 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. It is still your statement. It was the posters statement and my response to that statement. snip remaining puerile drivel Wrong again, as the archives prove. And you can't lie your way out of it. You can copy and paste. But you do not UNDERSTAND. So much drama, so little time... :| |
It is a truism
On 11/15/2014 1:58 PM, wrote:
On Saturday, November 15, 2014 12:40:29 PM UTC-6, Jerry Stuckle wrote: On 11/15/2014 12:58 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 10:02 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. It is still your statement. It was the posters statement and my response to that statement. snip remaining puerile drivel Wrong again, as the archives prove. And you can't lie your way out of it. You can copy and paste. But you do not UNDERSTAND. So much drama, so little time... :| I just don't want people to think his crap is the truth. It's far from it. He makes all kinds of claims - which knowledgeable people know are false. But others might get the wrong idea. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
On Saturday, November 15, 2014 1:01:20 PM UTC-6, Jerry Stuckle wrote:
On 11/15/2014 1:58 PM, wrote: On Saturday, November 15, 2014 12:40:29 PM UTC-6, Jerry Stuckle wrote: On 11/15/2014 12:58 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 10:02 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 4:26 PM, wrote: Jerry Stuckle wrote: On 11/14/2014 3:55 PM, wrote: Jerry Stuckle wrote: snip You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. You ignore the fact this is modeled on an AVERAGE environment. But you claim it is an absolute fact that an 80 meter antenna at less than 100' is crap. This is solid proof. I never made any such claim nor did I say "an 80 meter antenna at less than 100' is crap". That's true. You said is sucks. Let me quote you: "Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths." That was in response to the original poster who said his antenna sucked, not me. It is still your statement. It was the posters statement and my response to that statement. snip remaining puerile drivel Wrong again, as the archives prove. And you can't lie your way out of it. You can copy and paste. But you do not UNDERSTAND. So much drama, so little time... :| I just don't want people to think his crap is the truth. It's far from it. He makes all kinds of claims - which knowledgeable people know are false. But others might get the wrong idea. Yet, when I do the same with the one who's name shalt not be mentioned, I'm a drama queen.. :/ |
It is a truism
On 11/14/2014 8:36 AM, Jerry Stuckle wrote:
On 11/13/2014 6:12 PM, wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) False logic. You don't know how many people with good signals are using G5RV's, because you only ask those with poor signals. Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Yes and no. Depending on their design, short antennas can be very efficient. See http://www.futurity.org/radio-wave-c...phones-801322/ for an example. But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. snip I strongly encourage you to use a "loaded" 1 foot long dipole on 75 meters. This will prove you are right and we can all listen to the proof. :-) |
It is a truism
On 11/14/2014 2:49 PM, Ralph Mowery wrote:
"Jerry Stuckle" wrote in message ... On 11/14/2014 12:34 PM, wrote: You ignore the fact this is an idealized environment. That is NEVER the case in a real installation. I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only 50' in the air. And late at night in the wintertime I had pretty solid communications over much of the continental U.S. (back in the late 70's and early 80's). Antennas NEVER work "as predicted" - and anyone who claims they do does not understand antenna operation. Antennas 'always' work as predicted. People just don't always factor in everything in the prediction. Just as I worked a station on 432 MHz with 25 watts to a 1/4 wave ground plane that was about 1000 miles away. Nice bit of tropo that day. I bet I could put up a g5rv at 30 feet on some rare country and get loads of 5/9 signals no mater how many times the calls had to be repeatd. Please do put up your G5RV. We could all do with less QRM. And sure, all antennas work as predicted. I love the irony. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
It is a truism
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It is a truism
On 11/13/2014 7:06 PM, Wimpie wrote:
El 13-11-14 21:39, FBMboomer escribió: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. I agree that in many practical circumstances electrically small antennas do not perform well. I also know that having an antanna is better than nothing. The smaller the antenna, the more difficulties you will experience to get radiation out of it (heat radiation doesn't count). In free space you can make a rather efficient antenna with say maximum size of 0.03lambda, as long as you are a good electron tamer. If not, electrons escape from the structure showing a nice corona, or full breakdown occurs. Examples are tuned loops and short dipoles with capacitive end plates and series inductors to arrive at some nice impedance. Tuning in the shack with lots of cable and a bad ferrite balun between tuner and antenne mostly results in good VSWR but low efficiency (as many people know). In real world even a very small very efficient antenna may not perform as expected Close to the antenna (say within 0.1 lambda), reactive fields are very strong and they increase rapidly when reducing the distance. This is also valid for "magnetic loops" (that Jennings HV vacuum capacitor or thick potato cutter/slicer is for a reason). When you put such a nice small antenna close to lossy dielectric (building materials, ground, etc), significant part of the RF power may be dissipated in that lossy dielectric materials. In case of short monopoles, lots of power is mostly dissipated in the ground/counterpoise system (saline wetlands, sea and large metallic surfaces excepted). Of course we can solve this with lots of burried radials, or somewhat less elevated radials, but such solutions don't qualify for an electrically small antenna anymore. Wimpie, Let them use short antennas. Do not discourage them. It makes more room on 75 for those of us using full size antennas and power. They can talk around the block about how great there antenna is, and not bother anyone else. I hope the biggest antenna they ever use is a G5RV. |
It is a truism
On 11/13/2014 9:21 PM, Channel Jumper wrote:
But most people do not have access to tower that can get their dipole antenna 100' off the ground for 75 meters! The G5RV was designed to work on 20 meters. The ladder line is the matching network. It does not perform well on 10 or 40 meters. That usually has something to do with a cut dipole not working well on anything that is the first harmonic. A portion of this planet is inhabited by morons that does not know that and that picks their antenna by price rather than by performance! My inverted V - 80M off center fed dipole antenna is only 30' off the ground in the middle and maybe 20' off the ground on the ends. It is fed with about 60' of LMR 400 and I can converse with anyone that I can hear. Most of the people I hear are using 600 - 1200 watt amplifiers and some other type of dipole antenna, and although their signal is louder than mine, my audio is much cleaner then theirs! To me - amplifiers are for CB'rs that are hard of hearing and thinks that you cannot carry on a conversation unless you are 20/9! When I become a O&O - the first thing I am going to do is send each and every one of those people a pink slip and have them explain why they use more power than necessary. I would keep on sending them pink slips until they either get the message - that the reason for the signal report is so you can adjust your power to the minimum amount necessary to carry on the conversation, or until the ARRL / FCC gets tired of it and sends them a greetings to come and see them and explain why they can't follow the rules! As far as these people bragging about how they pick on those that are on a G5RV - I would gladly send them pink slips also - until they reduce their power or answer for their actions in front of a FCC examiner... I would love to see how many of these people could still pass a General Class Examination and how many of them bought their license and will let it drop - if they are asked to retest... OH Channel Jumper, you will be so powerful as an O&O. Your pink slips will surely intimidate everyone. They will just operate they way you want them to operate. Just think of the satisfaction you will get sending that pink slip. Never mind that it is an exercise in impotency. Did it ever occur to you that running the power necessary to communicate is not quantifiable by any standard but your own. How little S/N ratio are you willing to hear. If you like noise instead of audio then by all means demand that your contact reduce power. |
It is a truism
On Saturday, November 15, 2014 5:25:01 PM UTC-6, FBMboomer wrote:
Yes, smaller is better. I strongly encourage you to use 1/4 inch antennas. It is like homeopathy, less is more powerful. Getting your antenna length down to microns is the answer. Are you suggesting I use a 33 ft tall mobile antenna? Or are you just being silly because you have no other alternatives? |
It is a truism
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It is a truism
On 11/15/2014 6:17 PM, FBMboomer wrote:
On 11/14/2014 8:36 AM, Jerry Stuckle wrote: On 11/13/2014 6:12 PM, wrote: FBMboomer wrote: On 11/12/2014 1:50 PM, gareth wrote: It is a truism that short antennae are poor inefficient radiators, and no amount of infantile bluster by Americanoramuses will change that. The truth does not need the violence of abuse to force its way down people's throats. A perfect example is a G5RV on 75 meters. They suck. When someone joins our group rag chew on 75, and they have a poor signal, The first thing I ask is "Are you using a G5RV". We all have a chuckle when they answer yes and then ask how we knew. :-) False logic. You don't know how many people with good signals are using G5RV's, because you only ask those with poor signals. Trying to prove with math that short antennae work as well as say a 1/2 wave dipole may give someone great sport. However, in the real world, short antennae suck big time. I have been an American for most of my life. Please do not paint us all with the same brush. Yes and no. Depending on their design, short antennas can be very efficient. See http://www.futurity.org/radio-wave-c...phones-801322/ for an example. But others are correct. The antenna itself is an efficient radiator; it's the matching network that lowers *antenna system* efficiency. Any dipole type antenna will suck on 75M if mounted less than about 100 feet, or about .4 wavelengths. Below that you are warming clouds. So now it's 100 feet? It used to be 60 feet. But I have proof that is not the case. So do a lot of other hams I know. Your "facts" are for an idealized installation. Reality is much different, and will never get the ideal specifications you claim. snip I strongly encourage you to use a "loaded" 1 foot long dipole on 75 meters. This will prove you are right and we can all listen to the proof. :-) I suggest you stop trolling. You obviously have too much time on your hands (and too little brains to do anything productive). No wonder you wish to remain anonymous. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
It is a truism
FBMboomer wrote:
On 11/15/2014 6:23 PM, wrote: On Saturday, November 15, 2014 5:25:01 PM UTC-6, FBMboomer wrote: Yes, smaller is better. I strongly encourage you to use 1/4 inch antennas. It is like homeopathy, less is more powerful. Getting your antenna length down to microns is the answer. Are you suggesting I use a 33 ft tall mobile antenna? Or are you just being silly because you have no other alternatives? If a short antenna is just as good as a full size dipole, than why not use a 1/4 inch antenna. Or might there be something said for large full size antennas? Or could it be, size actually matters. I love clueless latecomers... -- Jim Pennino |
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