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#12
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I have just seen a range of low-loss thin ad flexible 50 ohm coax - aircell 7, ecoflex 10, ecoflex 15. If its as good as it claims to be, i would be great for use on boats for both HF and VHF. Has anyone used it? Yup, great stuff. Not as flexible and thin as RG-58, but a lot more than RG-213 (?). As an installer and repairman, we used foam dielectric coax once in a while for cell phone antennas because of UHF loss problems. It isn't as durable as RG-213 (the standard for most installations around salt water, as it crushes and flattens easier than solid dielectric. There were some brands of foam dielectric coax that absorbed moisture that degrades coax very quickly. RG-58 is ok for short runs of 25 watt VHF, but in tall masts, it just doesn't cut it. Also, it is a little light weight for 100 watt plus HF installations. The obvious weak link in most masthead installations is in the PL-259 coax connector installation. There are not many out there who can do a proper, watertight soldering job up at the top of a wavering, windy masthead. Been there, done that, was not always proud of my work. Old Chief Lynn, W7LTQ, PG-13-20604 |
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#13
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Lynn Coffelt wrote:
I have just seen a range of low-loss thin ad flexible 50 ohm coax - aircell 7, ecoflex 10, ecoflex 15. If its as good as it claims to be, i would be great for use on boats for both HF and VHF. Has anyone used it? Yup, great stuff. Not as flexible and thin as RG-58, but a lot more than RG-213 (?). As an installer and repairman, we used foam dielectric coax once in a while for cell phone antennas because of UHF loss problems. It isn't as durable as RG-213 (the standard for most installations around salt water, as it crushes and flattens easier than solid dielectric. There were some brands of foam dielectric coax that absorbed moisture that degrades coax very quickly. RG-58 is ok for short runs of 25 watt VHF, but in tall masts, it just doesn't cut it. Also, it is a little light weight for 100 watt plus HF installations. The obvious weak link in most masthead installations is in the PL-259 coax connector installation. There are not many out there who can do a proper, watertight soldering job up at the top of a wavering, windy masthead. Been there, done that, was not always proud of my work. Old Chief Lynn, W7LTQ, PG-13-20604 Hay, chief, did ya ever think to push the wire down the mast using a messenger to guide it, like the old wire being replaced, or a fish line? that way, you leave the end with the on deck pre installed connector on it at the top and outside the mast with a drip loop*, while you cut to length and terminate the bottom end below decks, or at the mast base, an easy job, or at least not so awkward as at the top of a wobbly mast, which you heel a bit to guide the messenger. (Damn! dropped the flux, again;-) Is the soldering iron plugged in?) I once climbed to the top of a big fir to cut off the top for a Christmas tree, but dropped the axe after I got up there. Had to go down and up three times all together, once just to get my arms, which fell off next! If you were a masthead radio tech, and not proud of your work, you would have done it again, unless it was your own life at risk. Cobbler's shoes? Dija ever go up just to unscrew, remove and then rescrew the connector, then wait for a radio check after pulling gently on the feeder? It could benefit from doing it once every year. How long do hams spend sending? Rael hams use code, light duty cycle, to set up fax, etc, with old contacts. Or do they want full duplex stereo video to remote studios, at 450 megs using meteor scatter at days' ends, with gigantic yagis doublesteered at the masthead? I saw one like that, once, on a 40 foot ketch in green lapstrake on Grand Lake. Mil RG58 is good enough for most, cheap, light. Communications is our most valuable resource. *Note: A typical drip loop style exit from the mast head would cause compression of the dielectric. Soft cable with long heights hanging should be clamped above the exit hole, sealed with caulk, double clamped or wirehung to the mast, properly sized and torqued, No drip loop, unless needed to meet the antenna mount. Masts should be able to drain at the heel anyway. Matching coils should be below the masthead, 2"-3" away from the mast. Tilting the antenna a little to avoid instrumentation is ok, though it may affect directivity at extremes. Terry K -Yeah, yeah, we *can* build monster cables. -SofDevCo- |
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#14
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Hay, chief, did ya ever think to push the wire down the mast using a
messenger to guide it, like the old wire being replaced, or a fish line? that way, you leave the end with the on deck pre installed connector on it at the top and outside the mast with a drip loop*, while you cut to length and terminate the bottom end below decks, or at the mast base, an easy job, or at least not so awkward as at the top of a wobbly mast, which you heel a bit to guide the messenger. (Damn! dropped the flux, again;-) Is the soldering iron plugged in?) I once climbed to the top of a big fir to cut off the top for a Christmas tree, but dropped the axe after I got up there. Had to go down and up three times all together, once just to get my arms, which fell off next! If you were a masthead radio tech, and not proud of your work, you would have done it again, unless it was your own life at risk. Cobbler's shoes? Dija ever go up just to unscrew, remove and then rescrew the connector, then wait for a radio check after pulling gently on the feeder? It could benefit from doing it once every year. How long do hams spend sending? Rael hams use code, light duty cycle, to set up fax, etc, with old contacts. Or do they want full duplex stereo video to remote studios, at 450 megs using meteor scatter at days' ends, with gigantic yagis doublesteered at the masthead? I saw one like that, once, on a 40 foot ketch in green lapstrake on Grand Lake. Mil RG58 is good enough for most, cheap, light. Communications is our most valuable resource. *Note: A typical drip loop style exit from the mast head would cause compression of the dielectric. Soft cable with long heights hanging should be clamped above the exit hole, sealed with caulk, double clamped or wirehung to the mast, properly sized and torqued, No drip loop, unless needed to meet the antenna mount. Masts should be able to drain at the heel anyway. Matching coils should be below the masthead, 2"-3" away from the mast. Tilting the antenna a little to avoid instrumentation is ok, though it may affect directivity at extremes. Terry K -Yeah, yeah, we *can* build monster cables. -SofDevCo- Hey, Terry! I like it, I like it! Can tell you've been there! Yes, when customers wanted to put the cable in themselves, (Glee!) I would sometimes help them figger a suitable length, and put one connector on in the nice warm shop, advising them to put the cable in, top down, and call me for the bottom connector. When you told of the tree, I initially knew you were bragging about the size of your Christmas tree. Upon closer inspection, I now know that you only used the top! The duty cycle on my 10 meter CW rig is way less than a thousandth of a percent. Usually giving it 8 to 10 months to cool down between contacts. However if one chose some of the FSK modes (I don't, personally), and had a little less than perfect SWR (and 100 watts or so) One can melt or soften current nodes in RG-58. Contributing, one would assume to Global Warming. Old Chief Lynn |
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#15
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Terry Spragg wrote in
: Rael hams use code Yeah....Pactor code, Amtor code, Packet code, PSK31 code, Baudot code....(c; REAL hams use digital modes. -- Larry |
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#16
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Rael hams use code Yeah....Pactor code, Amtor code, Packet code, PSK31 code, Baudot code....(c; REAL hams use digital modes. -- Larry Ah heck! And here I thought CW was the granddaddy of digital. Lynn |
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#17
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"Lynn Coffelt" wrote in
: Ah heck! And here I thought CW was the granddaddy of digital. Lynn I have some old friends, even friends who operated CW on subs in WW2, who've just become enthralled with PSK31 digital mode. If your transceiver has VOX, you don't even need any interface box expense. A 10K pot to control drive from the soundcard to the mic jack is plenty. Hookup is almost too easy. I use Winwarbler, which can copy three simultaneous stations on slightly different frequencies. PSK is SUPERIOR to the finest CW station. It will copy a DX PSK station so far into the noise you can't even tell there are tones in the noise, much less copy Morse from it if he were sending in Morse. PSK stations, to reduce interference in the 3Khz bandwidth the gentlemen's agreement puts them on at 14.070, usually use only 10 or 20 watts of power, even on the other side of the planet. It's uncanny that a cheap little soundcard can pull those tones out of the noise with such accuracy. Ham radio hasn't done much "inventing" in the past 30 years, but PSK is a ham radio invention that should be enjoyed by all. Tune your HF to 14.070 SSB and listen for tiny warbling tones. Plug the headphone jack into the LINE IN on your computer and run the Winwarbler software you get from: http://www.qsl.net/winwarbler/ Point your mouse at any little trace in the waterfall display and click on it. Winwarbler starts decoding instantly in the current window. Click the next window and pick another signal trace. It's that easy...(c; Instructions for use and installation are on the webpage. Simply amazing mode of RTTY comms between stations, with the simplest of equipment. Pick a trace you can hardly make out in the display and click on it...watch it type...(c; -- Larry |
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#18
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Ah heck! And here I thought CW was the granddaddy of digital. Lynn I have some old friends, even friends who operated CW on subs in WW2, who've just become enthralled with PSK31 digital mode. If your transceiver has VOX, you don't even need any interface box expense. A 10K pot to control drive from the soundcard to the mic jack is plenty. Hookup is almost too easy. I use Winwarbler, which can copy three simultaneous stations on slightly different frequencies. PSK is SUPERIOR to the finest CW station. It will copy a DX PSK station so far into the noise you can't even tell there are tones in the noise, much less copy Morse from it if he were sending in Morse. PSK stations, to reduce interference in the 3Khz bandwidth the gentlemen's agreement puts them on at 14.070, usually use only 10 or 20 watts of power, even on the other side of the planet. It's uncanny that a cheap little soundcard can pull those tones out of the noise with such accuracy. Ham radio hasn't done much "inventing" in the past 30 years, but PSK is a ham radio invention that should be enjoyed by all. Tune your HF to 14.070 SSB and listen for tiny warbling tones. Plug the headphone jack into the LINE IN on your computer and run the Winwarbler software you get from: http://www.qsl.net/winwarbler/ Point your mouse at any little trace in the waterfall display and click on it. Winwarbler starts decoding instantly in the current window. Click the next window and pick another signal trace. It's that easy...(c; Instructions for use and installation are on the webpage. Simply amazing mode of RTTY comms between stations, with the simplest of equipment. Pick a trace you can hardly make out in the display and click on it...watch it type...(c; -- Larry Larry, thanks, I've always wanted a simple way to look at PSK31, and have read a little. Your explanation of how to get started sounds like something even I can do. I do have a couple of pretty hot computer's that I assembled and run right here next to a fairly good HF receiver. I'm going to give it a listen. Unfortunately, transceiver is not something in the inventory, but have been lurking for a good deal on a used. Low power works, no doubt with advanced forms of digital, better than we ever did with CW, but you know 10 or 15 watts into a 6V6 or 6L6 worked the world every winter on 40. Friends (not me) copied down in the dirt and heterodyne jungle. The human ear and brain are darned near as sharp as the digital processing developments used in the later "automatic" Loran C receivers. Stop Lynn, while you're still ahead. Old Chief Lynn |
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#19
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#20
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"Lynn Coffelt" wrote in message ... Hay, chief, did ya ever think to push the wire down the mast using a messenger to guide it, like the old wire being replaced, or a fish line? that way, you leave the end with the on deck pre installed connector on it at the top and outside the mast with a drip loop*, while you cut to length and terminate the bottom end below decks, or at the mast base, an easy job, or at least not so awkward as at the top of a wobbly mast, which you heel a bit to guide the messenger. (Damn! dropped the flux, again;-) Is the soldering iron plugged in?) I once climbed to the top of a big fir to cut off the top for a Christmas tree, but dropped the axe after I got up there. Had to go down and up three times all together, once just to get my arms, which fell off next! If you were a masthead radio tech, and not proud of your work, you would have done it again, unless it was your own life at risk. Cobbler's shoes? Dija ever go up just to unscrew, remove and then rescrew the connector, then wait for a radio check after pulling gently on the feeder? It could benefit from doing it once every year. How long do hams spend sending? Rael hams use code, light duty cycle, to set up fax, etc, with old contacts. Or do they want full duplex stereo video to remote studios, at 450 megs using meteor scatter at days' ends, with gigantic yagis doublesteered at the masthead? I saw one like that, once, on a 40 foot ketch in green lapstrake on Grand Lake. Mil RG58 is good enough for most, cheap, light. Communications is our most valuable resource. *Note: A typical drip loop style exit from the mast head would cause compression of the dielectric. Soft cable with long heights hanging should be clamped above the exit hole, sealed with caulk, double clamped or wirehung to the mast, properly sized and torqued, No drip loop, unless needed to meet the antenna mount. Masts should be able to drain at the heel anyway. Matching coils should be below the masthead, 2"-3" away from the mast. Tilting the antenna a little to avoid instrumentation is ok, though it may affect directivity at extremes. Terry K -Yeah, yeah, we *can* build monster cables. -SofDevCo- Hey, Terry! I like it, I like it! Can tell you've been there! Yes, when customers wanted to put the cable in themselves, (Glee!) I would sometimes help them figger a suitable length, and put one connector on in the nice warm shop, advising them to put the cable in, top down, and call me for the bottom connector. When you told of the tree, I initially knew you were bragging about the size of your Christmas tree. Upon closer inspection, I now know that you only used the top! The duty cycle on my 10 meter CW rig is way less than a thousandth of a percent. Usually giving it 8 to 10 months to cool down between contacts. However if one chose some of the FSK modes (I don't, personally), and had a little less than perfect SWR (and 100 watts or so) One can melt or soften current nodes in RG-58. Contributing, one would assume to Global Warming. Old Chief Lynn So far no one has mentioned RAG-8X, which I see more of on boats these days than RAG-58. A second thing, what ever coax you use, use a stranded center conductor for marine use. I have repaired way to many fractured solid wire RAG-58 cables, broken right at or just beyond the PL259. I learned the pull it from the top with the connector already installed trick years ago doing type N connectors on RAG-8 or 213/214 for airport VHF radio antennas. I also learned to have a few adapters in my pocket before going on the roof/tower as you never knew what gender of N connectors the antenna stub might have. Also, please note that RAG-8 was dropped from the MilSpec books years ago and RAG-213 replaced it or the even better shielded RAG-214. Most of the RAG-8 you find available now says type RAG-8, not with a suffix, etc., to indicate a jacket or dielectric or solid or stranded wire. Radio Shack has been pawning junk off on unsuspecting citizens band ops for years, calling it type RAG-8. Since the standard has been deleted, they can get away with it. If you are going beyond RAG-8X (size of RAG-59), go with at least RAG-213 or the even better Belden cable. By the way, there is a type N connector around now that is just about the same as a PL-259, solder the center pin and shield there same way, with no more rubber gasket and compression nuts, etc. 73 Doug K7ABX "real radios glow in the dark!" Smoke signals and drum beats preceded CW as a digital mode! |
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