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Confused over coax and windom - newbie
I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special.
I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. --------------= Posted using GrabIt =---------------- ------= Binary Usenet downloading made easy =--------- -= Get GrabIt for free from http://www.shemes.com/ =- |
Confused over coax and windom - newbie
On Sun, 27 May 2007 13:40:06 +0100, "Andre C" wrote:
I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special. I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. --------------= Posted using GrabIt =---------------- ------= Binary Usenet downloading made easy =--------- -= Get GrabIt for free from http://www.shemes.com/ =- An inexpensive volt-ohm meter, $10-20 American, would allow you to test for shorts or continuity. (Or maybe you could rig a flashlight to test for shorts.) bob k5qwg |
Confused over coax and windom - newbie
On Sun, 27 May 2007 08:26:24 -0500, Bob Miller
wrote: On Sun, 27 May 2007 13:40:06 +0100, "Andre C" wrote: I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special. I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. --------------= Posted using GrabIt =---------------- ------= Binary Usenet downloading made easy =--------- -= Get GrabIt for free from http://www.shemes.com/ =- An inexpensive volt-ohm meter, $10-20 American, would allow you to test for shorts or continuity. (Or maybe you could rig a flashlight to test for shorts.) bob k5qwg Most, if not all, Carolina windoms use a voltage balun and therfore will show continuity between the coax's center conductor and shield. Danny, K6MHE |
Confused over coax and windom - newbie
On 27 May, 14:59, Danny Richardson wrote:
On Sun, 27 May 2007 08:26:24 -0500, Bob Miller wrote: On Sun, 27 May 2007 13:40:06 +0100, "Andre C" wrote: I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special. I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. --------------= Posted using GrabIt =---------------- ------= Binary Usenet downloading made easy =--------- -= Get GrabIt for free fromhttp://www.shemes.com/ =- An inexpensive volt-ohm meter, $10-20 American, would allow you to test for shorts or continuity. (Or maybe you could rig a flashlight to test for shorts.) bob k5qwg Most, if not all, Carolina windoms use a voltage balun and therfore will show continuity between the coax's center conductor and shield. Danny, K6MHE I have done some tests and am happy with coax. So I am left with the antenna. I am sorry but the quoted comment means very little to me in my newbie status. |
Confused over coax and windom - newbie
helmsman wrote:
PLEASE set you character count, so it fits on a line in the window. Like 90 characters per line. Thank You Or, you could use a newsreader which does proper line wrapping, regardless of the format proposed by the sender ... Thunderbird is excellent, even OE can do it ... JS |
Confused over coax and windom - newbie
On 27 May, 18:14, John Smith I wrote:
helmsman wrote: PLEASE set you character count, so it fits on a line in the window. Like 90 characters per line. Thank You Or, you could use a newsreader which does proper line wrapping, regardless of the format proposed by the sender ... Thunderbird is excellent, even OE can do it ... JS Thanks for the lessons. I use forte Agent but just happened to be on another computer and needed to post in a hurry. Any chance my problem could be explored further? I have now also ruled out the line isolator as a problem. |
Confused over coax and windom - newbie
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Confused over coax and windom - newbie
PLEASE set you character count, so it fits on a line in the window. Like 90 characters per line. Thank You GEE, That was helpful. Please set your character count to zero and ... Thank YOU |
Confused over coax and windom - newbie
Take your coax loose from the isolator. Get some kind of continuity device
(VOM / battery and bulb / etc) and check to see if your coax is shorted. If so, there's your problem. Then you can work on finding the short. Each time you do something, check continuity again to see if what you did clears the fault. If your coax is OK, then call the folks who made the antenna. If it's Radio Works, they're very helpful. They can talk you through some simple things to try to further troubleshoot. |
Confused over coax and windom - newbie
Andre C wrote:
I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special. I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. --------------= Posted using GrabIt =---------------- ------= Binary Usenet downloading made easy =--------- -= Get GrabIt for free from http://www.shemes.com/ =- OK. Let's apply logic here ... 1) If you have used a VOM and there is continuity between the center conductor of one end of the coax, with the center conductor of the opposite end of the coax, the center conductor is ok. 2) If you have continuity between the outer conductor of one end of the coax (shield) with the outer conductor of the opposite end of the coax (shield), the outer shield of the coax is ok. 3) If there is NO continuity between the center conductor of the coax and the outer conductor of the coax, the coax has checked out completely. Without knowing the construction details of the "line isolator" (probably a ~6:1 balun or rf transformer of some sort) it is impossible to know whether a short in this unit is normal (ok) or not. However, if the center conductor of the coax connector on the "line isolator" shows continuity with at least one leg of the windom, it shows there is continuity through the "line isolator" from the coax center conductor to the antenna proper. And, if there is continuity to at least one leg of the windom to the outer conductor of the coax connector on the coax connector on the "line isolator", it demonstrates there is continuity from the outer conductor of the coax to the antenna proper. At this point, I would assume the "line isolator" to be defective in some unknown way (most likely improper hookup at the factory, solder short, open winding, etc.) I am afraid that is the best I can come up with. I am taking it for granted the antenna is the "Carolina Windom 80 Special" made by Radio Works and is 66 feet long (well, short actually!) 80 - 10 meters and can be found on this page: http://radioworks.com/ccwcover.html Warmest regards, JS |
Confused over coax and windom - newbie
On Sun, 27 May 2007 22:40:57 -0700, John Smith I
wrote: OK. Let's apply logic here ... 1) If you have used a VOM and there is continuity between the center conductor of one end of the coax, with the center conductor of the opposite end of the coax, the center conductor is ok. 2) If you have continuity between the outer conductor of one end of the coax (shield) with the outer conductor of the opposite end of the coax (shield), the outer shield of the coax is ok. snip Warmest regards, JS In view of your logic, let me tell you about my situation recently when I tested a piece of coax on which I installed on connector. There were already two connectors on the coax and I removed one that was crimped and had slipped. I put on my connector and tested it with my radio, no signal. Hmm, I needed to check the wire. 1) I tested the center conductor and the shield on the connector I just installed... Short. OOPS! I cut off the connector and replaced it. 2) Tested the center conductor and shield on the connector I just installed... Short. OOPS again. 3) after cutting off my connector again, I tested the other connector. between the coax and shield. Open. Great! :) I soldered on the connector for the third time. 4) tested the center lead and shield of my connector... SHORT! Hmmmm 5) I cut off my connector and tested again. Open ????? I tested the other connector again. Open. ahhhh. I tested the center conductor from end to end.... OPEN!!! I tested the center conductor to the shield on the end where I was installing my connector.... SHORT!!!! Time for a new piece of coax.... 73 for now Buck N4PGW -- 73 for now Buck, N4PGW www.lumpuckeroo.com "Small - broadband - efficient: pick any two." |
Confused over coax and windom - newbie
Buck wrote:
You were either working with one EXPENSIVE piece of coax (and attempting to save the pocket book)--else you demonstrate your super human perseverance! JS |
Confused over coax and windom - newbie
On May 28, 8:24 am, Buck wrote:
In view of your logic, let me tell you about my situation recently when I tested a piece of coax on which I installed on connector. There were already two connectors on the coax and I removed one that was crimped and had slipped. I put on my connector and tested it with my radio, no signal. Hmm, I needed to check the wire. 1) I tested the center conductor and the shield on the connector I just installed... Short. OOPS! I cut off the connector and replaced it. 2) Tested the center conductor and shield on the connector I just installed... Short. OOPS again. 3) after cutting off my connector again, I tested the other connector. between the coax and shield. Open. Great! :) I soldered on the connector for the third time. 4) tested the center lead and shield of my connector... SHORT! Hmmmm 5) I cut off my connector and tested again. Open ????? I tested the other connector again. Open. ahhhh. I tested the center conductor from end to end.... OPEN!!! I tested the center conductor to the shield on the end where I was installing my connector.... SHORT!!!! Time for a new piece of coax.... Sounds like too much heat.. You may be melting the clear jacket and shorting the pin to shield. Be careful using too much heat when soldering the shield. Sounds like you have a manly soldering gun.. MK |
Confused over coax and windom - newbie
wrote:
Sounds like you have a manly soldering gun.. MK Or an underpowered one which produces too great an area under the temp vs. time curve. An old-fashioned iron with a high thermal mass tip is less likely to damage the coax. Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Confused over coax and windom - newbie
On Mon, 28 May 2007 07:55:53 -0700, John Smith I
wrote: Buck wrote: You were either working with one EXPENSIVE piece of coax (and attempting to save the pocket book)--else you demonstrate your super human perseverance! JS actually, I was thinking I was just that sloppy.... lol -- 73 for now Buck, N4PGW www.lumpuckeroo.com "Small - broadband - efficient: pick any two." |
Confused over coax and windom - newbie
On Mon, 28 May 2007 15:56:10 -0400, Chuck
wrote: wrote: Sounds like you have a manly soldering gun.. MK Or an underpowered one which produces too great an area under the temp vs. time curve. An old-fashioned iron with a high thermal mass tip is less likely to damage the coax. Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Inside the coax near the other connector, the wire had broken and one of the broken ends shorted the coax, the other broken end touched nothing. I had to look long and hard. It was apparently just a defect. It also happened to be the only accessible piece of coax handy at the time. As stated above, I was just thinking I was shorting out the coax connector, but when I cut it loose and it wasn't shorted, i knew it had to be at the other end. However, the other end appeared to be non-shorted. It wasn't till I took time to test the length of center conductor that I discovered the open. -- 73 for now Buck, N4PGW www.lumpuckeroo.com "Small - broadband - efficient: pick any two." |
Confused over coax and windom - newbie
Buck wrote:
... Buck: I have fought things like you describe only to fail and go to bed angry .... then get up in the morning and see the problem immediately! :-) Regards, JS |
Confused over coax and windom - newbie
On Mon, 28 May 2007 20:19:40 -0700, John Smith I
wrote: Buck wrote: ... Buck: I have fought things like you describe only to fail and go to bed angry ... then get up in the morning and see the problem immediately! :-) Regards, JS I know the feeling -- 73 for now Buck, N4PGW www.lumpuckeroo.com "Small - broadband - efficient: pick any two." |
Confused over coax and windom - newbie
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Confused over coax and windom - newbie
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Confused over coax and windom - newbie
On older models of Carolina Windoms, the line isolator was simply a
piece of RG-8x coax, with one end wrapped around a ferrite rod (and housed inside a piece of PVC). If you do away with the line isolator and hook your coax directly to the balun (I think they use a 4:1), you should receive signals just like any other dipole. If you do not, I'd say the balun is bad. If you do, then the line isolator is bad. If this is a new antenna from Radio Works, they will probably make it good. If it's a used antenna you can try to fix it yourself. Take a hacksaw to the PVC and get it apart. You may find a broken or unsoldered wire. You will need some new PVC caps, pipe, glue and such to make new housings, but that shouldn't be difficult. Kingfish On Sun, 27 May 2007 13:40:06 +0100, "Andre C" wrote: I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special. I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. |
Confused over coax and windom - newbie
wrote in message ... On older models of Carolina Windoms, the line isolator was simply a piece of RG-8x coax, with one end wrapped around a ferrite rod (and housed inside a piece of PVC). If you do away with the line isolator and hook your coax directly to the balun (I think they use a 4:1), you should receive signals just like any other dipole. If you do not, I'd say the balun is bad. If you do, then the line isolator is bad. If this is a new antenna from Radio Works, they will probably make it good. If it's a used antenna you can try to fix it yourself. Take a hacksaw to the PVC and get it apart. You may find a broken or unsoldered wire. You will need some new PVC caps, pipe, glue and such to make new housings, but that shouldn't be difficult. Kingfish On Sun, 27 May 2007 13:40:06 +0100, "Andre C" wrote: I am very new at ham radio and find myself confused over an installation of a Carolina windom 80 special. I attatched a 20m run of coax to the line isolator. When I switch on the rig I get nothing, even on strong BC stations. I assumed it was a coax prob and striped my plugs down etc. I then discovered that if the shielding was not touching the socket on the rig I got a very good signal. So I assumed there was a short in the coax. I checked the plugs and they seem fine but I note that even when I have just the co-ax plugged in (ie no windom) I get a good signal unless the shielding is connected. (I guess that would make sense though I thought the shielding stopped the centre core picking up a signal. So where is my problem? Is it the antenna? Is it the ine isolator. (There is no indicator which way round it goes so I presume it is universal.) I have no tset equipment as yet so an easy solution would be valuable. I never could really figure out a windom except that the origional was just a flat top that was tuner friendly on all the ham bands. Jimmie |
Confused over coax and windom - newbie
In article ,
Jimmie D wrote: I never could really figure out a windom except that the origional was just a flat top that was tuner friendly on all the ham bands. As I understand it, the original Windom is essentially a vertical radiator, with an asymmetrical capacitive "top-hat" (which will probably radiate at least a bit because of its asymmetry), bottom-fed, working against the station's RF ground. It's simply a form of Marconi antenna. The "Carolina Windom" is a very different sort of antenna... AIUI it's a off-center-fed doublet which (by design) also has some vertically-polarized radiation from the upper portion of its coaxial feedline. Although the two have a superficial resemblance, I believe that the two types have very different distributions of RF current, feedpoint impedances, and (probably) radiation patterns and polarization distributions. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Confused over coax and windom - newbie
Dave Platt wrote:
In article , Jimmie D wrote: I never could really figure out a windom except that the origional was just a flat top that was tuner friendly on all the ham bands. As I understand it, the original Windom is essentially a vertical radiator, with an asymmetrical capacitive "top-hat" (which will probably radiate at least a bit because of its asymmetry), bottom-fed, working against the station's RF ground. It's simply a form of Marconi antenna. The "Carolina Windom" is a very different sort of antenna... AIUI it's a off-center-fed doublet which (by design) also has some vertically-polarized radiation from the upper portion of its coaxial feedline. Although the two have a superficial resemblance, I believe that the two types have very different distributions of RF current, feedpoint impedances, and (probably) radiation patterns and polarization distributions. Yes, my 1957 ARRL Handbook makes the distinction between the single-wire feed of the Windom vs the transmission line feed of an Off-Center Fed (OCF) dipole. The currents at the vertical wire to horizontal wire junction in a Windom are flowing in opposite directions in the horizontal wire. The currents at the Carolina Windom's coax to horizontal wire interface are flowing in the same direction, more like an OCF dipole than a Windom. It was probably a marketing ploy to call it a "Windom" when it was not. "Carolina OCF" doesn't have much of a ring to it. -- 73, Cecil http://www.w5dxp.com |
Confused over coax and windom - newbie
"Dave Platt" wrote in message ... In article , Jimmie D wrote: I never could really figure out a windom except that the origional was just a flat top that was tuner friendly on all the ham bands. As I understand it, the original Windom is essentially a vertical radiator, with an asymmetrical capacitive "top-hat" (which will probably radiate at least a bit because of its asymmetry), bottom-fed, working against the station's RF ground. It's simply a form of Marconi antenna. The "Carolina Windom" is a very different sort of antenna... AIUI it's a off-center-fed doublet which (by design) also has some vertically-polarized radiation from the upper portion of its coaxial feedline. Although the two have a superficial resemblance, I believe that the two types have very different distributions of RF current, feedpoint impedances, and (probably) radiation patterns and polarization distributions. I tried to do an analysis on the antenna several years ago having an LCR bridge at my disposal and basically I found an antenna built for the ham bands to be non resonant on any of the ham bands, Had an input impdance of a few hundred ohms on all the hf bands and the reactive portion of the impedance could be handled by most tuners. The relatively high feedpoint impedance probably made it radiate reasonably efficently with even a mediocre ground system. I think the top hat may have been eithr capacitive or inductive depending on which band you were on and/or which leg of the top hat you were talking about. As I remember an antenna 10 M tall by 10M wide would tune up easily on all the bands 10 thru 80 but I am curious to what the radition patterns would look like. I would think they may not be so good on some of the bands. Jimmie |
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