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Use of lattice line to feed dipole
I have just strung a dipole of length of about 110 feet between a tree and
my house chimney. The primary use of the antenna will be 80 and 40 meters, with occasional use on the bands between 40 and 10 meters. My junk box contains a reel of open wire feeder (#16 solid copper wires with 1 inch white plastic spacers spaced about every 5 inches), which would run from my Johnson KW Matchbox to the dipole's center insulator. I have never used this type of feed line before, and in fact I believe its intended use was as a low-loss feed for TV. I am wondering if I could eliminate a fair amount of aggravation for myself by using a newer poly-coated window-type ladder line with #14 stranded copper-clad conductors for the feeder. Can this type of feeder handle high power? For skimpy specs on the ladder-line feed see http://tinyurl.com/ouzye |
Use of lattice line to feed dipole
On Fri, 22 Sep 2006 01:08:08 GMT, "John, N9JG"
wrote: I have just strung a dipole of length of about 110 feet between a tree and my house chimney. The primary use of the antenna will be 80 and 40 meters, with occasional use on the bands between 40 and 10 meters. My junk box contains a reel of open wire feeder (#16 solid copper wires with 1 inch white plastic spacers spaced about every 5 inches), which would run from my Johnson KW Matchbox to the dipole's center insulator. I have never used this type of feed line before, and in fact I believe its intended use was as a low-loss feed for TV. I am wondering if I could eliminate a fair amount of aggravation for myself by using a newer poly-coated window-type ladder line with #14 stranded copper-clad conductors for the feeder. Can this type of feeder handle high power? For skimpy specs on the ladder-line feed see http://tinyurl.com/ouzye Go with the junk box stuff. It will have lower losses - especially when it is wet. A much better choice. Danny, K6MHE |
Use of lattice line to feed dipole
Concure. Plus it will have a MUCH lower wind resistance. My window type
feeders with copperweld wire break about once a year due to wind whipping. Good choice! Paul, KD7HB Danny Richardson wrote: On Fri, 22 Sep 2006 01:08:08 GMT, "John, N9JG" wrote: I have just strung a dipole of length of about 110 feet between a tree and my house chimney. The primary use of the antenna will be 80 and 40 meters, with occasional use on the bands between 40 and 10 meters. My junk box contains a reel of open wire feeder (#16 solid copper wires with 1 inch white plastic spacers spaced about every 5 inches), which would run from my Johnson KW Matchbox to the dipole's center insulator. I have never used this type of feed line before, and in fact I believe its intended use was as a low-loss feed for TV. I am wondering if I could eliminate a fair amount of aggravation for myself by using a newer poly-coated window-type ladder line with #14 stranded copper-clad conductors for the feeder. Can this type of feeder handle high power? For skimpy specs on the ladder-line feed see http://tinyurl.com/ouzye Go with the junk box stuff. It will have lower losses - especially when it is wet. A much better choice. Danny, K6MHE |
Use of lattice line to feed dipole
I certainly appreciate the comments and advice from you and the other
respondents. -- John, N9JG "Edmund H. Ramm" wrote in message ... In "John, N9JG" writes: [...] My junk box contains a reel of open wire feeder (#16 solid copper wires with 1 inch white plastic spacers Zo abt 450 Ohms. spaced about every 5 inches), which would run from my Johnson KW Matchbox to the dipole's center insulator. [...] I am wondering if I could eliminate a fair amount of aggravation for myself by using a newer poly-coated window-type ladder line with #14 stranded copper-clad conductors for the feeder. You'd be in for problems. The windowed (not so)open-wire line is almost as susceptible to humidity and dirt as twinlead. If you want to buy open-wire line, get W7FG's 600 Ohms "real ladder line". If you use the feedline from your junkbox, make sure it doesn't swing in the wind. Solid copper wire will fatigue (and break) much sooner than the stranded variety. Can this type of feeder handle high power? [...] More power than RG-213 et.al., even more so when unmatched. 73, Eddi ._._. -- e-mail: dk3uz AT darc DOT de | AMPRNET: If replying to a Usenet article, please use above e-mail address. Linux/m68k, the best U**x ever to hit an Atari! |
Use of lattice line to feed dipole
On Fri, 22 Sep 2006 22:46:22 GMT, "John, N9JG"
wrote: I certainly appreciate the comments and advice from you and the other respondents. -- John, N9JG John, I think you will benefit from this. http://k6mhe.com/n7ws/Ladder_Line.pdf Danny, K6MHE |
Use of lattice line to feed dipole
An excellent article. It appears to indicate that at 7 MHz a feed line made
from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. "Danny Richardson" wrote in message ... On Fri, 22 Sep 2006 22:46:22 GMT, "John, N9JG" wrote: I certainly appreciate the comments and advice from you and the other respondents. -- John, N9JG John, I think you will benefit from this. http://k6mhe.com/n7ws/Ladder_Line.pdf Danny, K6MHE |
Use of lattice line to feed dipole
John, N9JG wrote:
An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. I've often wondered how someone "wets" a vertical feedline without using soap. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 01:50:54 GMT, Cecil Moore
wrote: I've often wondered how someone "wets" a vertical feedline without using soap. Cecil, Just drop by my qth anytime between November and May. Danny, K6MHE |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 00:48:43 GMT, "John, N9JG"
wrote: An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. Is that the matched line loss you are talking about. These lines aren't always or even often operated at very low VSWR, so it may be unwise to dismiss the loss as insignificant in the general sense. Owen -- |
Use of lattice line to feed dipole
Danny Richardson wrote:
Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore
wrote: Danny Richardson wrote: Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. I don't do anything. Ever heard of Oregon mist? When I first moved up here on the northern California coast I put up a doublet feeding it with window line. The next spring when I dropped the antenna for some maintenance I found moss growing on the feed line.Need I say it was replaced with something better? Danny |
Use of lattice line to feed dipole
You probably should read the article yourself, but Table 1 of the article
contains columns for matched line db attenuation per 100 feet for dry and wet lines. This set of data is from measurements made at 50 MHz. Since attenuation scales as the square root of frequency, I came up with a rough estimate for loss at 7 MHz. The author then goes on and uses modeling to predict some surprisingly large line losses for the G5RV antenna at 1.9 MHz. "Owen Duffy" wrote in message ... On Sat, 23 Sep 2006 00:48:43 GMT, "John, N9JG" wrote: An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. Is that the matched line loss you are talking about. These lines aren't always or even often operated at very low VSWR, so it may be unwise to dismiss the loss as insignificant in the general sense. Owen -- |
Use of lattice line to feed dipole
The author used a wetting agent.
"Cecil Moore" wrote in message m... John, N9JG wrote: An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. I've often wondered how someone "wets" a vertical feedline without using soap. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 04:32:51 GMT, "John, N9JG"
wrote: You probably should read the article yourself, but Table 1 of the article contains columns for matched line db attenuation per 100 feet for dry and wet lines. This set of data is from measurements made at 50 MHz. Since attenuation scales as the square root of frequency, I came up with a rough A widely accepted line loss model is that attenuation = k1 * f^0.5 + k2 * f, your approximation makes k2=0. estimate for loss at 7 MHz. The author then goes on and uses modeling to predict some surprisingly large line losses for the G5RV antenna at 1.9 MHz. Not surprised at all, many of the figures in the article at http://www.vk1od.net/G5RV/index.htm show the loss in ladder line in a G5RV feed system. Fig 3 shows that dry ladder line loss is not insignificant in the general sense, and Fig 8 shows the expected degradation on "wet line" in that application using Wes' characterisation. Owen -- |
Use of lattice line to feed dipole
John, N9JG wrote:
You probably should read the article yourself, but Table 1 of the article contains columns for matched line db attenuation per 100 feet for dry and wet lines. This set of data is from measurements made at 50 MHz. Since attenuation scales as the square root of frequency, I came up with a rough estimate for loss at 7 MHz. The author then goes on and uses modeling to predict some surprisingly large line losses for the G5RV antenna at 1.9 MHz. Resistive conductor loss is proportional to the square root of frequency, because of the relationship between skin depth and frequency. The loss of wet ladder line is almost entirely dielectric loss, not resistive conductor loss. In good dielectrics, loss is directly proportional to frequency. However, water is quite different from a good dielectric and with different loss mechanisms, so I wouldn't hazard a guess as to how it might vary with frequency. In an experiment I did many years ago with 300 ohm twinlead (http://www.eznec.com/Amateur/Article...eed_Lines.pdf), I found that the loss of wet line was significantly different just after it rained (when the line had presumably accumulated dust) than after it rained for some time. Roy Lewallen, W7EL |
Use of lattice line to feed dipole
Owen Duffy wrote:
A widely accepted line loss model is that attenuation = k1 * f^0.5 + k2 * f, your approximation makes k2=0. . . . In that model, k1 is attenuation due to conductor resistance, which is proportional to the square root of frequency as long as the conductor thickness is at least several skin depths. K2 is dielectric loss, which is proportional to frequency for good dielectrics. So this model is good for common transmission lines like coax or dry twinlead, at HF and above, but not necessarily valid for loss due to water. I commented more about this in another posting. Roy Lewallen, W7EL |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 00:32:04 -0700, Roy Lewallen
wrote: Owen Duffy wrote: A widely accepted line loss model is that attenuation = k1 * f^0.5 + k2 * f, your approximation makes k2=0. . . . In that model, k1 is attenuation due to conductor resistance, which is proportional to the square root of frequency as long as the conductor thickness is at least several skin depths. K2 is dielectric loss, which is proportional to frequency for good dielectrics. So this model is good for common transmission lines like coax or dry twinlead, at HF and above, but not necessarily valid for loss due to water. I commented more about this in another posting. Roy, I agree re the wet lines application. A further issue is that of standardisation of the wet line. Wes' work and yours shows that there is a degradation, but there is uncertainty regarding the scale of degradation, and effects like salt build up in marine locations could be expected to influence results at the start of rainfall and after torrential rainfall for instance. I do often use TV ribbon for temporary / portable antennas, tuning the antenna by adjusting the feedline length. I tend to avoid ground dependent antennas for this purpose, and a dipole with TV ribbon has some advantages, but as you note in your article, and as we have all observed, the "tuning" changes with rainfall more than would be observed with a coax feedline. Since your article was published, RG6 has become popular for TV feedline, and is cheap as chips. It performs very well, and I find myself using it for portable antennas. RG6 is a little heavier than RG58C/U (~30%), a little thicker, but has relatively low loss, approaching that of RG213 as a dipole feedline. I wonder if anyone has every critically appraised various forms of RG6 for through braid leakage and IMD? I know there is variability in quality, some seem to not locate the centre conductor in the true centre of the dielectric, and aluminium wire braid can be a disadvantage for solder-ability. (Cecil will correct the spelling if you don't know what I mean!) Owen -- |
Use of lattice line to feed dipole
Cecil Moore wrote:
Danny Richardson wrote: Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. No it doesn't!! You just can't see what surface tension causes to 'stick' |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 00:27:39 -0700, Roy Lewallen
wrote: In an experiment I did many years ago with 300 ohm twinlead (http://www.eznec.com/Amateur/Article...eed_Lines.pdf), I found that the loss of wet line was significantly different just after it rained (when the line had presumably accumulated dust) than after it rained for some time. Hi Roy, Some time before Wes's article was published I tried to measure the stuff myself. I used an eighty foot length of the so call "450-ohm" window line. My problem was that I really didn't have very good equipment for making the measurements. I use both a MHJ-259B and an Autek RF-1. I took several measurements and plotted the results getting a relatively good scattering patterns and went with that. The line I used was brand new and clean. For wetting I sprayed the line using a fog nozzle which makes a good fine mist that "stuck" well. (Being a damp area I don't have the drying problems Wes has in Tucson) As best as I could determine the wet losses were about double those for the dry line. But, as I said my equipment was ham-grade at best so I sure wouldn't bet the farm on my findings. (Interestingly, I did measure the dry line's impedance at 408-ohms which matched Wes's findings right to the ohm.) AsI mentioned earlier post, I tried using window line here on the northern coast and found that after being up for about a year I had moss starting to grow on the line. Now that certainly is going to crank up the losses! The bottom line is I gave up using the stuff and, for my tuned fed applications I use open line. Danny, K6MHE |
Use of lattice line to feed dipole
Danny Richardson wrote:
As best as I could determine the wet losses were about double those for the dry line. Wow, from 0.2 dB to 0.4 dB. :-) Would the following work for measuring the wet/dry losses of 1/2 wavelength of ladder-line shorted at one end and an MFJ-259B on the other end? Measure the resonant purely resistive impedance at the open end. Wet the ladder-line and repeat the procedure. Calculate the losses. If the line were lossless, zero ohms would be read. The deviation away from zero ohms yields the magnitude of the loss in the line at the 1/2 wavelength resonant frequency. That's about 8.8 MHz for 50 ft. of ladder-line. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 14:32:19 GMT, Cecil Moore
wrote: Wow, from 0.2 dB to 0.4 dB. :-) Would the following work for measuring the wet/dry losses of 1/2 wavelength of ladder-line shorted at one end and an MFJ-259B on the other end? Measure the resonant purely resistive impedance at the open end. Wet the ladder-line and repeat the procedure. Calculate the losses. If the line were lossless, zero ohms would be read. The deviation away from zero ohms yields the magnitude of the loss in the line at the 1/2 wavelength resonant frequency. That's about 8.8 MHz for 50 ft. of ladder-line. You are assuming something that I am not. That is the measurements were accurate. Measuring anything to a fraction of a dB is most difficult - even with the best of equipment and mine was not. Danny, K6MHE |
Use of lattice line to feed dipole
John, N9JG wrote:
The author used a wetting agent. "Cecil Moore" wrote in message m... John, N9JG wrote: An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. I've often wondered how someone "wets" a vertical feedline without using soap. So is the lesson that Ladder line sucks, or is it that we shouldn't wash our ladder line with soap and water? 8^) Has anyone run tests on what "real" (open) ladder line does when you spray it with wetting agent and water? - 73 de Mike KB3EIA - |
Use of lattice line to feed dipole
On Fri, 22 Sep 2006 20:24:59 -0700, Danny Richardson
wrote: On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore wrote: Danny Richardson wrote: Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. Here's a photo of a piece of Danny's line (Wireman 552), after it set around in the Arizona 5% humidity for a while It was still green when I got it. http://www.k6mhe.com/n7ws/MossyLine.jpg What do you suppose the dielectic properties are when that stuff totally bridges the line and is wet? I don't do anything. Ever heard of Oregon mist? When I first moved up here on the northern California coast I put up a doublet feeding it with window line. The next spring when I dropped the antenna for some maintenance I found moss growing on the feed line.Need I say it was replaced with something better? |
Use of lattice line to feed dipole
Wes Stewart wrote:
Here's a photo of a piece of Danny's line (Wireman 552), after it set around in the Arizona 5% humidity for a while It was still green when I got it. http://www.k6mhe.com/n7ws/MossyLine.jpg That's pretty amazing. East Texas is relatively damp and green but I've never had moss growing on my ladder- line. Here, the rain comes and goes and doesn't last very long. What do you suppose the dielectic properties are when that stuff totally bridges the line and is wet? Sounds like a useful project for someone. The only thing on my ladder-line at the moment is a green six-inch long lizard looking at me through the window pane. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 15:23:07 -0400, Mike Coslo
wrote: John, N9JG wrote: The author used a wetting agent. "Cecil Moore" wrote in message m... John, N9JG wrote: An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. I've often wondered how someone "wets" a vertical feedline without using soap. So is the lesson that Ladder line sucks, or is it that we shouldn't wash our ladder line with soap and water? 8^) Some suggest coating the ladder line with various forms of waxes, eg silicon car polish for various reasons, including minimising the change to the line characteristics with precipitation. I don't know if there is reliable evidence as to the efficacy of these measures, and what compounds are to be preferred. I see it discussed on eham, but that doesn't necessarily mean it is bunk! I don't know that it is fair to say that "Ladder line sucks", but it is well known that it is adversely affected by moisture. Ladder line is not so good wet or dry as to disregard its losses in all situations (ie in general). Like everything, it has its limitations, and with knowledge we can use it effectively within those limitations. Owen -- |
Use of lattice line to feed dipole
Cecil Moore wrote:
Wes Stewart wrote: Here's a photo of a piece of Danny's line (Wireman 552), after it set around in the Arizona 5% humidity for a while It was still green when I got it. http://www.k6mhe.com/n7ws/MossyLine.jpg That's pretty amazing. East Texas is relatively damp and green but I've never had moss growing on my ladder- line. Here, the rain comes and goes and doesn't last very long. What do you suppose the dielectic properties are when that stuff totally bridges the line and is wet? Sounds like a useful project for someone. The only thing on my ladder-line at the moment is a green six-inch long lizard looking at me through the window pane. You sure that ain't just a reflection? 73, Tom Donaly, KA6RUH |
Use of lattice line to feed dipole
Wes Stewart wrote:
On Fri, 22 Sep 2006 20:24:59 -0700, Danny Richardson wrote: On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore wrote: Danny Richardson wrote: Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. Here's a photo of a piece of Danny's line (Wireman 552), after it set around in the Arizona 5% humidity for a while It was still green when I got it. http://www.k6mhe.com/n7ws/MossyLine.jpg What do you suppose the dielectic properties are when that stuff totally bridges the line and is wet? Seems as if some of us are taking special circumstances and applying them to all cases. I have the same type of line, and after several years, it's still glossy, and the water beads up on it. So should I quit using it because he has problems, or should he keep using it because I don't? ;^) - 73 de mike KB3EIA - |
Use of lattice line to feed dipole
Tom Donaly wrote:
You sure that ain't just a reflection? :-0 Nope, it's one of these critters called an Anole. Locals call them chameleons because they can change their colors from green to brown. http://www.kingsnake.com/hudspeth/AnoleClose1.jpg -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
Owen Duffy wrote:
On Sat, 23 Sep 2006 15:23:07 -0400, Mike Coslo wrote: John, N9JG wrote: The author used a wetting agent. "Cecil Moore" wrote in message .com... John, N9JG wrote: An excellent article. It appears to indicate that at 7 MHz a feed line made from 100' of Wireman 554 window line would have a loss of about 2 db when the line is wet. When the line is dry, the loss is insignificant. I've often wondered how someone "wets" a vertical feedline without using soap. So is the lesson that Ladder line sucks, or is it that we shouldn't wash our ladder line with soap and water? 8^) Some suggest coating the ladder line with various forms of waxes, eg silicon car polish for various reasons, including minimising the change to the line characteristics with precipitation. Hi Owen. I doubt that those would help much, as PE has some pretty impressive characteristics. I suspect that waxes and such will just degrade performance. And I can just imagine the look my XYL would give me if I told her I was going to go wax my line! ;^) I don't know if there is reliable evidence as to the efficacy of these measures, and what compounds are to be preferred. I see it discussed on eham, but that doesn't necessarily mean it is bunk! I don't know that it is fair to say that "Ladder line sucks", but it is well known that it is adversely affected by moisture. Ladder line is not so good wet or dry as to disregard its losses in all situations (ie in general). I wonder what the exact mechanism is? PE has some decent water absorption characteristics, 24 hour tests show almost no absorption for low density, and none for the high density and up versions. Like everything, it has its limitations, and with knowledge we can use it effectively within those limitations. I daresay you are right. - 73 de Mike KB3EIA - |
Use of lattice line to feed dipole
Cecil Moore wrote:
Tom Donaly wrote: You sure that ain't just a reflection? :-0 Nope, it's one of these critters called an Anole. Locals call them chameleons because they can change their colors from green to brown. Cute little duffer! - 73 de Mike KB3EIA - |
Use of lattice line to feed dipole
Owen Duffy wrote:
Some suggest coating the ladder line with various forms of waxes, eg silicon car polish for various reasons, including minimising the change to the line characteristics with precipitation. I have a spray can of NAPA MAC'S Silicone spray. It says: "Waterproofs and Insulates". I've got a thunderstorm on the way and just sprayed about 2 feet of my 450 ohm ladder- line with it. I'll see if I can tell where the silicone spray is and if it has any visible effect on the water. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 18:25:55 -0400, Mike Coslo
wrote: I don't know that it is fair to say that "Ladder line sucks", but it is well known that it is adversely affected by moisture. Ladder line is not so good wet or dry as to disregard its losses in all situations (ie in general). I wonder what the exact mechanism is? PE has some decent water absorption characteristics, 24 hour tests show almost no absorption for low density, and none for the high density and up versions. I don't recall seeing suggestion that the mechanism is a change to the PE due to absorption of water. The water on the surface of the PE is immersed in the E and H fields, and is likely to change the RLGC characteristics at a frequency. I think Wes' work was valuable in demonstrating that the changes are not lossless, even if it is not practical to estimate the magnitude of the changes because of uncertainty in the "wet environment" at any point in time. So, we know that the changes in loading that we observe with an ATU are likely to have an increased line loss due to the water. That loss warrants consideration, a reason to consider other line constructions in certain environments. Wes and I discussed inclusion of his "wet" figures in my line loss calculator at http://www.vk1od.net/tl/tllc.php . Wes' preference was to not include them, I am happy with that in that you could read too much into the calculated results because of the lack of standardised "wetness" in the real world. Owen -- |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 18:18:25 -0400, Mike Coslo
wrote: Wes Stewart wrote: On Fri, 22 Sep 2006 20:24:59 -0700, Danny Richardson wrote: On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore wrote: Danny Richardson wrote: Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. Here's a photo of a piece of Danny's line (Wireman 552), after it set around in the Arizona 5% humidity for a while It was still green when I got it. http://www.k6mhe.com/n7ws/MossyLine.jpg What do you suppose the dielectic properties are when that stuff totally bridges the line and is wet? Seems as if some of us are taking special circumstances and applying them to all cases. I have the same type of line, and after several years, it's still glossy, and the water beads up on it. The questioner asked how to keep the water on the line. An answer was provided. No mention was made that this was a universal problem. I return you to your regularly scheduled catfight. I will return to the woodwork. |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 23:01:06 GMT, Cecil Moore
wrote: I have a spray can of NAPA MAC'S Silicone spray. It says: "Waterproofs and Insulates". I've got a thunderstorm on the way and just sprayed about 2 feet of my 450 ohm ladder- line with it. I'll see if I can tell where the silicone spray is and if it has any visible effect on the water. I would suspect that any oil or wax compounds would be a tad sticky and may, over time, accumulate more dust on the surface. That, in turn, could in be a good rooting medium for moss and/or mildew to form? By the way I did spray my ladder line with silicone spray when I originally put it up. Danny |
Use of lattice line to feed dipole
Owen Duffy wrote:
I think Wes' work was valuable in demonstrating that the changes are not lossless, ... I think Reg would have chimed in about now reminding us that 50% loss is only 1/2 of an S-Unit. :-) -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
Danny Richardson wrote:
On Sat, 23 Sep 2006 23:01:06 GMT, Cecil Moore wrote: I have a spray can of NAPA MAC'S Silicone spray. It says: "Waterproofs and Insulates". I've got a thunderstorm on the way and just sprayed about 2 feet of my 450 ohm ladder- line with it. I'll see if I can tell where the silicone spray is and if it has any visible effect on the water. I would suspect that any oil or wax compounds would be a tad sticky and may, over time, accumulate more dust on the surface. That, in turn, could in be a good rooting medium for moss and/or mildew to form? By the way I did spray my ladder line with silicone spray when I originally put it up. I just took a look at my wet ladder-line with a flashlight. I cannot tell where I sprayed it with silicone. -- 73, Cecil http://www.w5dxp.com |
Use of lattice line to feed dipole
Danny Richardson wrote:
On Sat, 23 Sep 2006 23:01:06 GMT, Cecil Moore wrote: I have a spray can of NAPA MAC'S Silicone spray. It says: "Waterproofs and Insulates". I've got a thunderstorm on the way and just sprayed about 2 feet of my 450 ohm ladder- line with it. I'll see if I can tell where the silicone spray is and if it has any visible effect on the water. I would suspect that any oil or wax compounds would be a tad sticky and may, over time, accumulate more dust on the surface. That, in turn, could in be a good rooting medium for moss and/or mildew to form? By the way I did spray my ladder line with silicone spray when I originally put it up. Aha! I was troubled with how you got mold or moss or anything to stick to PE. I believe you are correct in your suspicions. One of PE's main draws is it's inertness, and it is a real bear trying to get anything to adhere to it. There is some possibility that the spray may have contributed to what appears to be pitting on the line. Certainly something troubles me with the idea that we can test something under conditions where we apply chemistry to alter a fundamental property of the material. (I'm referring to the wetting agent tests) I believe that the tests do show adequately how ladder line performs when covered with wetting agent and water. And that we don't want to do that! ;^) - 73 de mike KB3EIA - |
Use of lattice line to feed dipole
Wes Stewart wrote:
On Sat, 23 Sep 2006 18:18:25 -0400, Mike Coslo wrote: Wes Stewart wrote: On Fri, 22 Sep 2006 20:24:59 -0700, Danny Richardson wrote: On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore wrote: Danny Richardson wrote: Just drop by my qth anytime between November and May. How do you keep the water on the feedline? Mine always beads up and falls to the ground. Here's a photo of a piece of Danny's line (Wireman 552), after it set around in the Arizona 5% humidity for a while It was still green when I got it. http://www.k6mhe.com/n7ws/MossyLine.jpg What do you suppose the dielectic properties are when that stuff totally bridges the line and is wet? Seems as if some of us are taking special circumstances and applying them to all cases. I have the same type of line, and after several years, it's still glossy, and the water beads up on it. The questioner asked how to keep the water on the line. An answer was provided. No mention was made that this was a universal problem. I return you to your regularly scheduled catfight. Not trying to insult anyone here, Wes. Just trying to figure out what is going on. And after a little discourse, we find out that Daniel sprayed silicon spray of some sort on the line. That starts to make some sense of why he had a problem with the line. I'd wager his mold, moss, or mildew problem has more to do with his unapproved use of chemistry on the line. - 73 de Mike KB3EIA - |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 20:58:12 -0400, Mike Coslo
wrote: Aha! I was troubled with how you got mold or moss or anything to stick to PE. I believe you are correct in your suspicions. One of PE's main draws is it's inertness, and it is a real bear trying to get anything to adhere to it. There is some possibility that the spray may have contributed to what appears to be pitting on the line. Certainly something troubles me with the idea that we can test something under conditions where we apply chemistry to alter a fundamental property of the material. (I'm referring to the wetting agent tests) I believe that the tests do show adequately how ladder line performs when covered with wetting agent and water. And that we don't want to do that! ;^) - 73 de mike KB3EIA - Well Mike, along my experience with ladder line there is also Roy's and Wes's measurements. Based upon that, for me, I'm off the stuff. My present open line setup is appears to be working fine. No detectable moss, mildew or anything else that I can detect. One can go on forever trying to justify one way or the other, but thus far, wet ladder or ribbon line has shown not to be the best route to go - from three different sources. If you have something to the contrary I certainly would be interested in hearing about it. To each his own. Danny, K6MHE |
Use of lattice line to feed dipole
On Sat, 23 Sep 2006 21:29:39 -0400, Mike Coslo
wrote: I'd wager his mold, moss, or mildew problem has more to do with his unapproved use of chemistry on the line. Hi Mike, This doesn't explain mold, moss, or mildew that naturally occurs under very similar circumstances. 73's Richard Clark, KB7QHC, Rain City |
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