carolina windom vs dipole
Hi,
Have you some experience on the air using a Carolina Windom 40m long compared to a G5RV 31m (100 ft) long... I have the experience of G5RV but not the Windom yet. The objective is using them for local qso but also dx in ssb (according to their possibilities, thus not up to reach JA from ON or maybe via the grayline, to see..) I am going to install both (in NS and EW direction) but I really don't know which is best or if they are really on par. The Windom comes with 2 traps (1 per segment, as the standard design), a 6:1 balun ended with a coax. The G5RV is multiband too, without traps and uses a 4:1 balun ended with a 10m ladder line (standard design) , then a coax. There is this already 2 or 3 hardware differences. Knowing that one segment of the Windom is shorter, does it impact negatively the radiation pattern with e.g. more sensitivity to QRM or other "defect" that G5RV doesn't show ? NB. I could use HFANT or MutiNEC to simulate that but that required to input all antenna parameters first to design it before ask the program to simulate its pattern... a field experiment is faster and welcome ;-) Thanks in advance Thierry, ON4SKY |
On Thu, 16 Sep 2004 17:39:50 +0200, "Thierry"
http://www.astrosurf.com/lombry wrote: The objective is using them for local qso but also dx in ssb (according to their possibilities, thus not up to reach JA from ON or maybe via the grayline, to see..) Hi Thierry, One application (local/DX) has to suffer at the expense of the other. YOU have to choose which application you want as first choice. I am going to install both (in NS and EW direction) but I really don't know which is best or if they are really on par. This is another choice YOU have to make. What do YOU want to do? If it is grayline, you cannot do this very effectively with a dipole going North/South. Even going East/West will not result in the best if you work stations mostly in a ENE/WNW Great Circle bearing. You need to use a propagation program like WinVOA to see what design you need (dipole orientation that is) and then build to that bearing. If you build two antennas that are crossed (and even if one is Windom and the other G5RV); then you will have a suitable solution - somewhere (even if you drive them both and phase them). There is this already 2 or 3 hardware differences. These are practical problems of construction, not operational results. Knowing that one segment of the Windom is shorter, does it impact negatively the radiation pattern with e.g. more sensitivity to QRM or other "defect" that G5RV doesn't show ? Short answer: NO. Long answer: Yes. a field experiment is faster and welcome ;-) Only if we happen to be a neighbor - quel dommage. 73's Richard Clark, KB7QHC |
On Thu, 16 Sep 2004 16:05:39 GMT, Richard Clark wrote:
On Thu, 16 Sep 2004 17:39:50 +0200, "Thierry" http://www.astrosurf.com/lombry wrote: The objective is using them for local qso but also dx in ssb (according to their possibilities, thus not up to reach JA from ON or maybe via the grayline, to see..) Hi Thierry, One application (local/DX) has to suffer at the expense of the other. YOU have to choose which application you want as first choice. I am going to install both (in NS and EW direction) but I really don't know which is best or if they are really on par. This is another choice YOU have to make. What do YOU want to do? If it is grayline, you cannot do this very effectively with a dipole going North/South. Even going East/West will not result in the best if you work stations mostly in a ENE/WNW Great Circle bearing. You need to use a propagation program like WinVOA to see what design you need (dipole orientation that is) and then build to that bearing. If you build two antennas that are crossed (and even if one is Windom and the other G5RV); then you will have a suitable solution - somewhere (even if you drive them both and phase them). There is this already 2 or 3 hardware differences. These are practical problems of construction, not operational results. Knowing that one segment of the Windom is shorter, does it impact negatively the radiation pattern with e.g. more sensitivity to QRM or other "defect" that G5RV doesn't show ? Short answer: NO. Long answer: Yes. a field experiment is faster and welcome ;-) Only if we happen to be a neighbor - quel dommage. 73's Richard Clark, KB7QHC Hi Thierry, If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a dipole and the Caroling Windom is a dipole. Except for their use on harmonically ralated bands the radiation is the same for each. Any different radiation pattern on harmonically related bands results only from a difference in lengths of the dipoles. The dipole length of the traditional G5RV is 102 feet. If the Windom is cut for some longer length the pattern will be somehwhat different on the higher harmonic bands, but the difference will be rather insignificant. Walt, W2DU |
Taking one band with another and one direction with another, the difference
between a Windom and G5RV will be entirely undetectable. They will both have somewhat poorer performance than a simple random length dipole of about the same length and height fed over a random length, high impedance, any Zo, open-wire line. Following the study you have given to the subject, you may be disappointed at the responses to your question, But you did ask. And there's no reason why you should be deterred from experimenting with either or both types of antenna. You will then be at least as wise as us Old Wive's. If you should like playing with just a few numbers then amuse yourself with small programs DIPOLE3 and ENDFEED. Download from website below in a few seconds and run immediately. They provide lots of data but the most important thing is the single number - radiating efficiency! --- .................................................. .......... Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.btinternet.com/~g4fgq.regp .................................................. .......... |
Thanks for all comments.
I did a mistakle in my specs because they are no traps on the windom (I confused with W4DZZ). In fact I thought that both designs being wire antennas of almost the same length, they 'd display the same radiation pattern at a few percent. But I was focused on the shortest segment (1/3) of the windom and wonder whether it could cause or not additional problems or display drawbacks compared to a real dipole... In all case I will test it in 2 weeks. Problem with dipole3, the influence of a shorter segment is not taken into account. I don't know if that could be important, probably not much, but it 'd have been interesting to add some additional parameters like the length of each segment and the tilt of the tilt too to get a more accurate result. Addition: My believe is founded. I just find some radiation patterns and comments in the ARRL antenna book ch7-8. The windom is much more omnidirectional than a dipole. They say that "the system (windom) takes advantage of the asymmetry of the horizontal wires to induce current onto the braid of the vertical coax section.... The radiation pattern... tends to fill in the deep nulls that 'd be present ... if horizontally center fed". globally they consider that the windom give better results due to the omnidirectional pattern or so than a true dipole. Anyway, if I have the courage I will try to simulate the windom in Multinec. Thanks for the help Thierry, ON4SKY "Reg Edwards" wrote in message ... Taking one band with another and one direction with another, the difference between a Windom and G5RV will be entirely undetectable. They will both have somewhat poorer performance than a simple random length dipole of about the same length and height fed over a random length, high impedance, any Zo, open-wire line. Following the study you have given to the subject, you may be disappointed at the responses to your question, But you did ask. And there's no reason why you should be deterred from experimenting with either or both types of antenna. You will then be at least as wise as us Old Wive's. If you should like playing with just a few numbers then amuse yourself with small programs DIPOLE3 and ENDFEED. Download from website below in a few seconds and run immediately. They provide lots of data but the most important thing is the single number - radiating efficiency! --- .................................................. ......... Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.btinternet.com/~g4fgq.regp .................................................. ......... |
"Richard Clark" wrote in message
... On Thu, 16 Sep 2004 17:39:50 +0200, "Thierry" http://www.astrosurf.com/lombry wrote: The objective is using them for local qso but also dx in ssb (according to their possibilities, thus not up to reach JA from ON or maybe via the grayline, to see..) Hi Thierry, One application (local/DX) has to suffer at the expense of the other. YOU have to choose which application you want as first choice. I am going to install both (in NS and EW direction) but I really don't know which is best or if they are really on par. This is another choice YOU have to make. What do YOU want to do? If it is grayline, you cannot do this very effectively with a dipole going North/South. Even going East/West will not result in the best if you work stations mostly in a ENE/WNW Great Circle bearing. You need to use a propagation program like WinVOA to see what design you need (dipole orientation that is) and then build to that bearing. If you build two antennas that are crossed (and even if one is Windom and the other G5RV); then you will have a suitable solution - somewhere (even if you drive them both and phase them). Good idea, about simulation, I will try to create the windom design in multiprop or hfant (I know the one of the dipole) and then run the voacap to see what the matter. FYI here is the pattern at short distance of a G5RV, 100W, tight EW, http://www.astrosurf.com/lombry/Radi...p-on-la-12.gif The windom should be more omnidirectional. Thierry, ON4SKY There is this already 2 or 3 hardware differences. These are practical problems of construction, not operational results. Knowing that one segment of the Windom is shorter, does it impact negatively the radiation pattern with e.g. more sensitivity to QRM or other "defect" that G5RV doesn't show ? Short answer: NO. Long answer: Yes. a field experiment is faster and welcome ;-) Only if we happen to be a neighbor - quel dommage. 73's Richard Clark, KB7QHC |
"Thierry" http://www.astrosurf.com/lombry wrote in message ...
Hi, Have you some experience on the air using a Carolina Windom 40m long compared to a G5RV 31m (100 ft) long... Yea. I've tried both. They both are sort of lame compared to a normal coax fed dipole for a given band. I agree with Walt that a dipole is a dipole as far as pattern for a given band...The difference is how much power actually makes it to the antenna to be radiated. This is what separates the mediocre from the better. If I wanted to work dx, I would use neither of those antennas. But you don't mention what band you want to work dx...The lower the band, the better the standard coax fed dipoles in general. But on the other hand, the lower the band, and the better a good vertical would work compared to the dipole. :/ Anything can work dx on the higher bands unless the radiation angles are way too high. If you want all bands with a single wire, I would use the standard dipole cut for the lowest band, and feed with ladder line and a good tuner. Or no tuner with the Cecil method...Myself, I prefer paralleled dipoles fed with a single coax. Don't need a tuner, and the efficiency is high. The G5RV and the common storebought windom both have fairly lossy feedline systems for my tastes. And the windom is prone to common mode problems, etc...I don't like an unbalanced antenna unless it's a last resort. MK |
On Fri, 17 Sep 2004 01:12:30 +0200, "Thierry"
http://www.astrosurf.com/lombry wrote: FYI here is the pattern at short distance of a G5RV, 100W, tight EW, http://www.astrosurf.com/lombry/Radi...p-on-la-12.gif Hi Thierry, Hmmmm, I can see where the magnetic pole is. 73's Richard Clark, KB7QHC |
Ok Mark, for sure for DXing a dipole or a windom is not a beam...
From europe in SSB and barefoot (100W in SSB), with my G5RV tight EW I reach FY, PY, midwest US, VU, 4S, UA9J,C, RA9 artic, central africa. Hard to go farther bu these days of SSN decreasing. My objective is Dxing first as for local QSOs this is not a problem to get S9+. I know very well that DX performances will be more than limited, all the more in SSB, but this is a temporary solution waiting for a small beam 3-or 4 ele. Thierry, ON4SKY "Mark Keith" wrote in message om... "Thierry" http://www.astrosurf.com/lombry wrote in message ... Hi, Have you some experience on the air using a Carolina Windom 40m long compared to a G5RV 31m (100 ft) long... Yea. I've tried both. They both are sort of lame compared to a normal coax fed dipole for a given band. I agree with Walt that a dipole is a dipole as far as pattern for a given band...The difference is how much power actually makes it to the antenna to be radiated. This is what separates the mediocre from the better. If I wanted to work dx, I would use neither of those antennas. But you don't mention what band you want to work dx...The lower the band, the better the standard coax fed dipoles in general. But on the other hand, the lower the band, and the better a good vertical would work compared to the dipole. :/ Anything can work dx on the higher bands unless the radiation angles are way too high. If you want all bands with a single wire, I would use the standard dipole cut for the lowest band, and feed with ladder line and a good tuner. Or no tuner with the Cecil method...Myself, I prefer paralleled dipoles fed with a single coax. Don't need a tuner, and the efficiency is high. The G5RV and the common storebought windom both have fairly lossy feedline systems for my tastes. And the windom is prone to common mode problems, etc...I don't like an unbalanced antenna unless it's a last resort. MK |
Walter Maxwell wrote:
If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a dipole and the Caroling Windom is a dipole. Hi Walt, I don't know if you know or not, but the Carolina Windom is designed for the vertical section to radiate so it has a radiation pattern which is a combination of a dipole and a vertical. -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Thierry wrote:
Thanks for all comments. I did a mistakle in my specs because they are no traps on the windom (I confused with W4DZZ). In fact I thought that both designs being wire antennas of almost the same length, they 'd display the same radiation pattern at a few percent. But I was focused on the shortest segment (1/3) of the windom and wonder whether it could cause or not additional problems or display drawbacks compared to a real dipole... In all case I will test it in 2 weeks. Problem with dipole3, the influence of a shorter segment is not taken into account. I don't know if that could be important, probably not much, but it 'd have been interesting to add some additional parameters like the length of each segment and the tilt of the tilt too to get a more accurate result. Addition: My believe is founded. I just find some radiation patterns and comments in the ARRL antenna book ch7-8. The windom is much more omnidirectional than a dipole. They say that "the system (windom) takes advantage of the asymmetry of the horizontal wires to induce current onto the braid of the vertical coax section.... The radiation pattern... tends to fill in the deep nulls that 'd be present ... if horizontally center fed". globally they consider that the windom give better results due to the omnidirectional pattern or so than a true dipole. Anyway, if I have the courage I will try to simulate the windom in Multinec. Thanks for the help Thierry, ON4SKY "Reg Edwards" wrote in message ... Taking one band with another and one direction with another, the difference between a Windom and G5RV will be entirely undetectable. They will both have somewhat poorer performance than a simple random length dipole of about the same length and height fed over a random length, high impedance, any Zo, open-wire line. Following the study you have given to the subject, you may be disappointed at the responses to your question, But you did ask. And there's no reason why you should be deterred from experimenting with either or both types of antenna. You will then be at least as wise as us Old Wive's. If you should like playing with just a few numbers then amuse yourself with small programs DIPOLE3 and ENDFEED. Download from website below in a few seconds and run immediately. They provide lots of data but the most important thing is the single number - radiating efficiency! --- ................................................ ........... Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.btinternet.com/~g4fgq.regp ................................................ ........... Hi Thierry: The only draw back of the off center fed dipole is the possibility of introducing radiation from the feedline which can make for R.F. in the Shack if not properly acconted for , it also makes predicting the radiation pattern a little skewed to the long end of the dipole. I Use two off center fed dipoles (miss nomer windoms) here one is cut for 40m long the other 20m long the 40m long one is fed with a 4:1 balun and 75 ohm coax the 20m long is fed with 300 ohm open wire line to a tuner. both antennas do a good job for me. I do mostly causual dxing (but as one poster has already said you'll have to decide which propagation mode you are seeking if grayline put up a vertical or other lowangle radiator for 80meters.) They are mounted at 90 degrees to each other. I've been able to work lots of dx on these antennas .. I had two g5rv's up prior to these and from a pure operational veiw point find them a little better at my location. hope this is of some help. 73 Dave |
"Cecil Moore" wrote in message ... Walter Maxwell wrote: If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a dipole and the Caroling Windom is a dipole. Hi Walt, I don't know if you know or not, but the Carolina Windom is designed for the vertical section to radiate so it has a radiation pattern which is a combination of a dipole and a vertical. Indeed, all the interest of the thing..., hence my question. But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. Thierry, ON4SKY -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"KC1DI" wrote in message ... Thierry wrote: Thanks for all comments. ... I Use two off center fed dipoles (miss nomer windoms) here one is cut for 40m long the other 20m long the 40m long one is fed with a 4:1 balun and 75 ohm coax the 20m long is fed with 300 ohm open wire line to a tuner. both antennas do a good job for me. I do mostly causual dxing (but as one poster has already said you'll have to decide which propagation mode you are seeking if grayline put up a vertical or other lowangle radiator for 80meters.) They are mounted at 90 degrees to each other. I've been able to work lots of dx on these antennas .. I had two g5rv's up prior to these and from a pure operational veiw point find them a little better at my location. For sure the location add a bias factor, soil, rock, sand, trees, etc affect the radiation pattern, all the more that on my Windom the coax segment will be at 50% in trees... although the ladder line of my G5RV was in the air, off trees... Anyway, I will have the confirmation in a few weeks. If results are "unattended" I will post a new msg. 73 Thierry, ON4SKY hope this is of some help. 73 Dave |
I have used 160M Carolina windoms for the past 5 years or so and have
found them to be really good performers. The higher you can get the vertical element off the ground the better (I have had good results with it only 20' off the gorund....Radioworks recommends more). I have never modeled it, nor had experience with G5RV, but compared to a half wave dipole at similar height, my "impression" is that it performs at least as well, probably better, plus multiband. Beward you will need to use a tuner with it, and if you are running legal limit, be careful of your SWR's as you can burn out the balun or RF choke (they are not traps). There has been a lot of debate about this antenna, but I can tell you the 160M version works quite well on all bandsl. GL es 73 Dan (k0dan) On Fri, 17 Sep 2004 15:35:28 +0200, "Thierry" http://www.astrosurf.com/lombry wrote: "Cecil Moore" wrote in message ... Walter Maxwell wrote: If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a dipole and the Caroling Windom is a dipole. Hi Walt, I don't know if you know or not, but the Carolina Windom is designed for the vertical section to radiate so it has a radiation pattern which is a combination of a dipole and a vertical. Indeed, all the interest of the thing..., hence my question. But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. Thierry, ON4SKY -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
The original windom of the 1920's had a single wire (vertical)
feedline. The Carolina Windom as sold by Radioworks has RF radiation from the feedline which is a deliberate design consideration of this antenna; it has a vertical element (the piece of coax hanging off the balun) which is designed to radiate,. and which creates the low angle lobes. The RF radiation is STOPPED at the RF choke which is at the end of the "feedline". Then YOU feedline connects here and essentially does not radiate. There is alot of information on this antenna at http://www.radioworks.com/, some of which contradicts some of the mythology which appears in the NG's and reflectors.. 73 Dan (k0dan) Hi Thierry: The only draw back of the off center fed dipole is the possibility of introducing radiation from the feedline which can make for R.F. in the Shack if not properly acconted for , it also makes predicting the radiation pattern a little skewed to the long end of the dipole. I Use two off center fed dipoles (miss nomer windoms) here one is cut for 40m long the other 20m long the 40m long one is fed with a 4:1 balun and 75 ohm coax the 20m long is fed with 300 ohm open wire line to a tuner. both antennas do a good job for me. I do mostly causual dxing (but as one poster has already said you'll have to decide which propagation mode you are seeking if grayline put up a vertical or other lowangle radiator for 80meters.) They are mounted at 90 degrees to each other. I've been able to work lots of dx on these antennas .. I had two g5rv's up prior to these and from a pure operational veiw point find them a little better at my location. hope this is of some help. 73 Dave |
Indeed, all the interest of the thing..., hence my question.
But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. Thierry, ON4SKY Why would QRM be a problem ? The beter the antenna the more signal it will pick up. Maybe you ment QRN (noise) instead of M (undesired radio signals) ? |
"Thierry" http://www.astrosurf.com/lombry wrote in message ...
Ok Mark, for sure for DXing a dipole or a windom is not a beam... I'd rather have the coax fed dipole over the windom any day though...I bet many people would think it's a beam , the way it will most likely trounce the average windom. I tried one "windom" at a field day against a coax fed dipole. The dipole won by 2 s units in any direction. Thats about what you would see going from a coax dipole to an average beam...:/ Or by changing from 100w to 500w-1 KW... My objective is Dxing first as for local QSOs this is not a problem to get S9+. If it's working local, why would it not be working dx ok? Why the change to an antenna which basically will be the same, assuming element lengths are fairly close for a given band, barring any changes in feedline efficiency? IE: I assume you are going to switch from a G5RV to a windom.... Thinking about either one of those antennas makes me want to take up golf... I don't like either one. It's no secret though....:( The only thing the G5RV has going for it, is it is nearly a EDZ on 20m. But it's a reduced efficiency version compared to one fed in a normal manner... Coax to a choke to ladder line as a feedline is no way to live for a serious dx'er who wants most of his power to actually be radiated by the antenna element...The windom is not much better in this regard....Or at least the ones I've seen. I know very well that DX performances will be more than limited, all the more in SSB, but this is a temporary solution waiting for a small beam 3-or 4 ele. You still don't mention which band/s though... There are fairly simple wire antennas much better for dx than the usual all band compromise wire antenna. IE: extended double zepps, phased parallel dipoles, etc, etc. I would use something along those lines if I wanted to dx say 20m or up...If you want to dx 80/40, you might consider a bobtail curtain or variant, or a good vertical. Trying to increase the dx potential by changing from one semi lame antenna , to another semi lame antenna strikes me as counterproductive. But, it's your yard and $$$.... :/ MK |
"dmr" wrote in message ... I have used 160M Carolina windoms for the past 5 years or so and have found them to be really good performers. The higher you can get the vertical element off the ground the better (I have had good results with it only 20' off the gorund....Radioworks recommends more). I have never modeled it, nor had experience with G5RV, but compared to a half wave dipole at similar height, my "impression" is that it performs at least as well, probably better, plus multiband. Beward you will need to use a tuner with it, and if you are running legal limit, be careful of your SWR's as you can burn out the balun or RF choke (they are not traps). Hi, 160m long 20' high ? That must be interesting and u had to confirm over 100 dx with such a length... I very well know these problems of SWR etc,and many others. I am an OT you know,... Hi! I learnt the lesson in the past in experimenting live a bad SWR... youth errors as one tells... but interesting because I never more forget the lesson, like many others in experimenting myself. With some respect it it far better to be chocke a second and get a little blister due to a SWR over 5:1 using a kW amp that having hours of theory... because you cannot fix your idea on concrete things. For the rest, of course the heigth (and length) are VERY important, all using a dipole or windom all work fine or almost from 8m high and 20m long and up. Below your radiation pattern is seriously affected compared to the ideal solution (say 2-lamba over 12m high). And you feel that very well when trying to call CQ DX and even simple CQ up to 5000 km away. To get an idea simulate these specs in modeling software like multiprop that use a VOACAP engine, or even nec, hfant and others. See my best site for detail. Thanks for the help. 73 Thierry, ON4SKY There has been a lot of debate about this antenna, but I can tell you the 160M version works quite well on all bandsl. GL es 73 Dan (k0dan) On Fri, 17 Sep 2004 15:35:28 +0200, "Thierry" http://www.astrosurf.com/lombry wrote: "Cecil Moore" wrote in message ... Walter Maxwell wrote: If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a dipole and the Caroling Windom is a dipole. Hi Walt, I don't know if you know or not, but the Carolina Windom is designed for the vertical section to radiate so it has a radiation pattern which is a combination of a dipole and a vertical. Indeed, all the interest of the thing..., hence my question. But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. Thierry, ON4SKY -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"Ralph Mowery" wrote in message ink.net... Indeed, all the interest of the thing..., hence my question. But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. Thierry, ON4SKY Why would QRM be a problem ? The beter the antenna the more signal it will pick up. Maybe you ment QRN (noise) instead of M (undesired radio signals) ? No ! I speak of QRM, made made, due to vertical segment (vertical polarized I believed) that, i thougth, 'd pick up more QRM, in the same way as a vertical antenna coupled to a dipole tight horizontally e.g.. But in this case it doesn't as this is a common-mode choke balun ; there is no RF radiation form the coax. In all cases I will see the result in the field very soon, adn could appreciate both designs (dipole vs. windom). Thierry, ON4SKY |
"dmr" wrote in message ... The original windom of the 1920's had a single wire (vertical) feedline. The Carolina Windom as sold by Radioworks has RF radiation from the feedline which is a deliberate design consideration of this antenna; it has a vertical element (the piece of coax hanging off the balun) which is designed to radiate,. and which creates the low angle lobes. The RF radiation is STOPPED at the RF choke which is at the end of the "feedline". Then YOU feedline connects here and essentially does not radiate. I use a common chocke balun. the coax doesn radiates RF. Thierry There is alot of information on this antenna at http://www.radioworks.com/, some of which contradicts some of the mythology which appears in the NG's and reflectors.. 73 Dan (k0dan) Hi Thierry: The only draw back of the off center fed dipole is the possibility of introducing radiation from the feedline which can make for R.F. in the Shack if not properly acconted for , it also makes predicting the radiation pattern a little skewed to the long end of the dipole. I Use two off center fed dipoles (miss nomer windoms) here one is cut for 40m long the other 20m long the 40m long one is fed with a 4:1 balun and 75 ohm coax the 20m long is fed with 300 ohm open wire line to a tuner. both antennas do a good job for me. I do mostly causual dxing (but as one poster has already said you'll have to decide which propagation mode you are seeking if grayline put up a vertical or other lowangle radiator for 80meters.) They are mounted at 90 degrees to each other. I've been able to work lots of dx on these antennas .. I had two g5rv's up prior to these and from a pure operational veiw point find them a little better at my location. hope this is of some help. 73 Dave |
"Mark Keith" wrote in message
om... "Thierry" http://www.astrosurf.com/lombry wrote in message ... Ok Mark, for sure for DXing a dipole or a windom is not a beam... I'd rather have the coax fed dipole over the windom any day though...I Hi, No. For a true dipole and get a low impedance etc I prefer by far the ladder line; The coax is easier but is less performing This is not much difference, but measurable. I always prefered the optimum solution. bet many people would think it's a beam , the way it will most likely trounce the average windom. I tried one "windom" at a field day against a coax fed dipole. The dipole won by 2 s units in any direction. Thats about what you would see going from a coax dipole to an average beam...:/ Or by changing from 100w to 500w-1 KW... Ok. I will see but 2 S-unit are much. What is sure is that the radiation pattern of a carolina windom is next over a dipole : http://www.astrosurf.com/lombry/Radi...on-pattern.gif it is much more omnidorectionnal what could explain is overall better performance. My objective is Dxing first as for local QSOs this is not a problem to get S9+. If it's working local, why would it not be working dx ok? Why the change to an antenna which basically will be the same, assuming Local is not DX. High takeoff angle vs. very low. This is a huge difference if you check your receive strength signal. 73 Thierry, ON4SKY element lengths are fairly close for a given band, barring any changes in feedline efficiency? IE: I assume you are going to switch from a G5RV to a windom.... Thinking about either one of those antennas makes me want to take up golf... I don't like either one. It's no secret though....:( The only thing the G5RV has going for it, is it is nearly a EDZ on 20m. But it's a reduced efficiency version compared to one fed in a normal manner... Coax to a choke to ladder line as a feedline is no way to live for a serious dx'er who wants most of his power to actually be radiated by the antenna element...The windom is not much better in this regard....Or at least the ones I've seen. I know very well that DX performances will be more than limited, all the more in SSB, but this is a temporary solution waiting for a small beam 3-or 4 ele. You still don't mention which band/s though... There are fairly simple wire antennas much better for dx than the usual all band compromise wire antenna. IE: extended double zepps, phased parallel dipoles, etc, etc. I would use something along those lines if I wanted to dx say 20m or up...If you want to dx 80/40, you might consider a bobtail curtain or variant, or a good vertical. Trying to increase the dx potential by changing from one semi lame antenna , to another semi lame antenna strikes me as counterproductive. But, it's your yard and $$$.... :/ MK |
No, no, no.. I said the vertical element was 20' off the
ground....bottom of the vertical feedline 20' off the ground, means antennas height in the center was about 40-50'. dt On Sat, 18 Sep 2004 11:51:18 +0200, "Thierry" http://www.astrosurf.com/lombry wrote: "dmr" wrote in message .. . I have used 160M Carolina windoms for the past 5 years or so and have found them to be really good performers. The higher you can get the vertical element off the ground the better (I have had good results with it only 20' off the gorund....Radioworks recommends more). I have never modeled it, nor had experience with G5RV, but compared to a half wave dipole at similar height, my "impression" is that it performs at least as well, probably better, plus multiband. Beward you will need to use a tuner with it, and if you are running legal limit, be careful of your SWR's as you can burn out the balun or RF choke (they are not traps). Hi, 160m long 20' high ? That must be interesting and u had to confirm over 100 dx with such a length... I very well know these problems of SWR etc,and many others. I am an OT you know,... Hi! I learnt the lesson in the past in experimenting live a bad SWR... youth errors as one tells... but interesting because I never more forget the lesson, like many others in experimenting myself. With some respect it it far better to be chocke a second and get a little blister due to a SWR over 5:1 using a kW amp that having hours of theory... because you cannot fix your idea on concrete things. For the rest, of course the heigth (and length) are VERY important, all using a dipole or windom all work fine or almost from 8m high and 20m long and up. Below your radiation pattern is seriously affected compared to the ideal solution (say 2-lamba over 12m high). And you feel that very well when trying to call CQ DX and even simple CQ up to 5000 km away. To get an idea simulate these specs in modeling software like multiprop that use a VOACAP engine, or even nec, hfant and others. See my best site for detail. Thanks for the help. 73 Thierry, ON4SKY There has been a lot of debate about this antenna, but I can tell you the 160M version works quite well on all bandsl. GL es 73 Dan (k0dan) On Fri, 17 Sep 2004 15:35:28 +0200, "Thierry" http://www.astrosurf.com/lombry wrote: "Cecil Moore" wrote in message ... Walter Maxwell wrote: If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a dipole and the Caroling Windom is a dipole. Hi Walt, I don't know if you know or not, but the Carolina Windom is designed for the vertical section to radiate so it has a radiation pattern which is a combination of a dipole and a vertical. Indeed, all the interest of the thing..., hence my question. But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. Thierry, ON4SKY -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Thierry wrote:
But I wonder also about the QRM pick-up along this vertical segment... I will have the answer in two weeks. It is designed to radiate some vertically polarized energy so it is also designed to receiver some vertically polarized energy. That would render the Carolina Windom virtually useless at my QTH. -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Thierry wrote:
Without speaking about heigth above ground, QRG and length, how do we explain the more or less omnidirectional pattern against a dipole, see diagram at http://www.astrosurf.com/lombry/Radi...on-pattern.gif if there is no radiation from the coaxial ? The vertical coax section between the impedance matching device at the feedpoint and the RF choke is designed to radiate and it does. The coax between the RF choke and the source is designed not to radiate. -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"Cecil Moore" wrote in message ... Thierry wrote: Without speaking about heigth above ground, QRG and length, how do we explain the more or less omnidirectional pattern against a dipole, see diagram at http://www.astrosurf.com/lombry/Radi...on-pattern.gif if there is no radiation from the coaxial ? The vertical coax section between the impedance matching device at the feedpoint and the RF choke is designed to radiate and it does. The coax between the RF choke and the source is designed not to radiate. -- Hi Cecil, it is well what i though, but in my case this is a Carolina Windom like on this drawing http://www.astrosurf.com/lombry/Radi...windom-dwg.gif The balun is attached to the wire and there is no segment above it. the coax enter the balun and the otehr side goes to the TX hence my question. And is this design still a Carolina Windom, excepted the segemnts of 1/3 2/3, it looks more to a hybrid between the dipole and the Windom... isn't it ? And on this model, if it uses a choke balun (what is not sure) the coax 'd not radiate RF, othewhise of course if radiate much, like an vertical Thierry, ON4SKY 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
it is well what i though, but in my case this is a Carolina Windom like on
this drawing http://www.astrosurf.com/lombry/Radi...windom-dwg.gif The balun is attached to the wire and there is no segment above it. the coax enter the balun and the otehr side goes to the TX hence my question. And is this design still a Carolina Windom, excepted the segemnts of 1/3 2/3, it looks more to a hybrid between the dipole and the Windom... isn't it ? And on this model, if it uses a choke balun (what is not sure) the coax 'd not radiate RF, othewhise of course if radiate much, like an vertical Thierry, ON4SKY What you have is the standard Off Center Fed antenna. A true Windom is fed with a single wire about 1/3 the distance from one end. Many are calling the OCF antenna a Windom which it is not. The OCF antenna is often called a Windom by mistake. The Carolina Windom has about 6 meters of coax that is vertical below the horizontal part and then a common mode choke. The vertical is suspose to radiate some signal for DX and the horizontal is for a higher angle of radiation for the close in stations. I don't know if it actually works this way in practice , but that is their selling point. Here is a URL for the Carolina Windom. http://www.radioworks.com/ccwcover.html |
Thierry wrote:
it is well what i though, but in my case this is a Carolina Windom like on this drawing http://www.astrosurf.com/lombry/Radi...windom-dwg.gif The balun is attached to the wire and there is no segment above it. the coax enter the balun and the otehr side goes to the TX hence my question. And is this design still a Carolina Windom, ...? Good Grief! No, that is *NOT* a Carolina Windom, which is an antenna sold by Radio Works. Hopefully, they have it copyrighted and therefore can object to the above BS. See it at http://www.radioworks.com/ccwcover.html The antenna you mention is simply an off-center-fed dipole, not really a Windom at all. (Why are people with 65 IQ's allowed to build web pages?) -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"Cecil Moore" wrote in message ... Thierry wrote: it is well what i though, but in my case this is a Carolina Windom like on this drawing http://www.astrosurf.com/lombry/Radi...windom-dwg.gif The balun is attached to the wire and there is no segment above it. the coax enter the balun and the otehr side goes to the TX hence my question. And is this design still a Carolina Windom, ...? Good Grief! No, that is *NOT* a Carolina Windom, which is an antenna sold by Radio Works. Hopefully, they have it copyrighted and therefore can object to the above BS. See it at http://www.radioworks.com/ccwcover.html The antenna you mention is simply an off-center-fed dipole, not really a Windom at all. (Why are people with 65 IQ's allowed to build web pages?) the 65 IQ has nothing to do with it. The problem is that the manufacturer sold it as a Windom... and it is as it is off center fed... with a simple balun and coax, but the opposite is not true. Ok it is not a carolina, it 's only me who mixed both designs. 73 Thierry -- 73, Cecil, W5DXP -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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