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#1
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Roy Lewallen wrote in
: If there was a "best" cable, there would be only one type. Some have lower loss, some are more flexible, some have better weather resistance, some have better shielding, some have a longer lifetime, some tolerate temperature extremes better, some are more uniform, some are less expensive, and so forth. So deciding which cable is "better" requires a lot more information about what your requirements are. If I went into most places selling cables I'd get laughed at if I took that line, they'd say 'hie me to a research lab, if not an actual nunnery'. ![]() that you're wrong, but if you want a single general purpose cable for HF and VHF especially if stocking it for general sale, then there IS a 'best' cable, defined simply by that which most likely serves the wide range of purposes at a low price. Currently in the UK that cable seems to be RG6; few places like to stock more than one type for RF if they think one will do. Perfectionism is NOT the first base. It's reasonable to expect some standard without being told to either become an expert or use a bell wire and stay in ignorance. RG6 works, but they sell it for VHF/UHF, not RF. I'm not so concerned with moderate losses, but SNR maintained by good shielding matters to me. I take your point about poor foil/braid shields being worse than good braids. That's partly what drove my question. It seems to me that RG6 in all forms I have found is optimised for VHF and higher. Nothing I've seen either before or after that question has yet convinced me that RG6 is the better choice for HF. I've seen plenty of posts saying it will work, but just as many saying they've seen old RG59 cables doing fine at UHF too. So far I think I'm likely to go with the more costly double braided BT2002. Most posts I read stated that poor performance was usually due to difficulties connecting firmly to the soft aluminium shield than to the cable's own qualities. I suspect the extra cost for double copper braid will be repaid in easier (soldered) connections and other savings elsewhere, plus a certainty that it is effective at HF. I'm not going to be using it for UHF (although I have done once, it worked ok for a long TV aerial extension), and I've already used it for VHF with good results. Main thing with the BT2002 is that it's old, there might be something directly equivalent made for British Telecom data links now, perhaps thinner, or cheaper, or more flexible, but I don't know how to check for that. I've seen a list of BT type cables but I think it was as old as that cable is. Last time I got the BT2002 I found it, didn't have to pay for it. The only thing making me wary of it now is that it won't be free this time. ![]() |
#2
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Lostgallifreyan wrote:
Roy Lewallen wrote in : If there was a "best" cable, there would be only one type. Some have lower loss, some are more flexible, some have better weather resistance, some have better shielding, some have a longer lifetime, some tolerate temperature extremes better, some are more uniform, some are less expensive, and so forth. So deciding which cable is "better" requires a lot more information about what your requirements are. If I went into most places selling cables I'd get laughed at if I took that line, they'd say 'hie me to a research lab, if not an actual nunnery'. ![]() that you're wrong, but if you want a single general purpose cable for HF and VHF especially if stocking it for general sale, then there IS a 'best' cable, defined simply by that which most likely serves the wide range of purposes at a low price. Currently in the UK that cable seems to be RG6; few places like to stock more than one type for RF if they think one will do. . . Sounds like you have your answer, then. Roy Lewallen, W7EL |
#3
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Roy Lewallen wrote in
: Lostgallifreyan wrote: Roy Lewallen wrote in : If there was a "best" cable, there would be only one type. Some have lower loss, some are more flexible, some have better weather resistance, some have better shielding, some have a longer lifetime, some tolerate temperature extremes better, some are more uniform, some are less expensive, and so forth. So deciding which cable is "better" requires a lot more information about what your requirements are. If I went into most places selling cables I'd get laughed at if I took that line, they'd say 'hie me to a research lab, if not an actual nunnery'. ![]() purpose cable for HF and VHF especially if stocking it for general sale, then there IS a 'best' cable, defined simply by that which most likely serves the wide range of purposes at a low price. Currently in the UK that cable seems to be RG6; few places like to stock more than one type for RF if they think one will do. . . Sounds like you have your answer, then. Roy Lewallen, W7EL Yes, if I was using for UHF and perhaps VHF as they sell it for. But as far as I know the older UG59 used a braid with better physical coverage and was specified for HF as well. I'd rather get something this time that has good HF shielding as priority, so I'm not convinced that RG6 is the right choice. A bit of extra loss isn't as bad as poor shielding. |
#4
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Lostgallifreyan wrote:
Yes, if I was using for UHF and perhaps VHF as they sell it for. But as far as I know the older UG59 used a braid with better physical coverage and was specified for HF as well. I'd rather get something this time that has good HF shielding as priority, so I'm not convinced that RG6 is the right choice. A bit of extra loss isn't as bad as poor shielding. The standard for cable tv and satellite instalations is RG6 "quad shield", which has a less dense braid, but a (almost) 100% aluminum foil shield. The question is how do you connect to it? Commerical applications use special crimp on connectors, you can solder it with the proper flux. A friend brought some Radio Shack screw on PL-259 connectors that work fine with it, but they are $6 each in the US, and unavailable here. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia. |
#5
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"Geoffrey S. Mendelson" wrote in
: Lostgallifreyan wrote: Yes, if I was using for UHF and perhaps VHF as they sell it for. But as far as I know the older UG59 used a braid with better physical coverage and was specified for HF as well. I'd rather get something this time that has good HF shielding as priority, so I'm not convinced that RG6 is the right choice. A bit of extra loss isn't as bad as poor shielding. The standard for cable tv and satellite instalations is RG6 "quad shield", which has a less dense braid, but a (almost) 100% aluminum foil shield. As far I can tell from advice on HF, the thin foil doesn't shield as well at HF as a thicker braid with good physical coverage. The question is how do you connect to it? Commerical applications use special crimp on connectors, you can solder it with the proper flux. A friend brought some Radio Shack screw on PL-259 connectors that work fine with it, but they are $6 each in the US, and unavailable here. I found an RG6 at low cost with copper braid and Al foil (more likely metalised plastic film) so I can solder ok with that, but I'm going to be using this for HF, not UHF, and if anything, I want to include MF signals so as I mentioned in other posts, I'm not convinced that RG6 is the best choice, unless it's the only RF cable in the shop. ![]() |
#6
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On Sun, 31 Jan 2010 14:59:06 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: Lostgallifreyan wrote: Yes, if I was using for UHF and perhaps VHF as they sell it for. But as far as I know the older UG59 used a braid with better physical coverage and was specified for HF as well. I'd rather get something this time that has good HF shielding as priority, so I'm not convinced that RG6 is the right choice. A bit of extra loss isn't as bad as poor shielding. The standard for cable tv and satellite instalations is RG6 "quad shield", which has a less dense braid, but a (almost) 100% aluminum foil shield. The question is how do you connect to it? Commerical applications use special crimp on connectors, you can solder it with the proper flux. Compression fittings. Easy to install, strong, water proof, and about 50 cents each. A friend brought some Radio Shack screw on PL-259 connectors that work fine with it, but they are $6 each in the US, and unavailable here. And a waste of money. The problem with the compression fittings is you need a compression tool to install them although a pair of the "duck billed" vise grips, or even pliers could be adapted to do the job. You only need hold the front and back of the connector and then push the pack part with the seal into the front part...a distance of maybe 1/8" (4mm) . The commercial tools are kinda pricey, but you can make one up out of a pair of pliers and a bit of ingenuity. 73 Roger (K8RI) Geoff. |
#7
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On Sun, 31 Jan 2010 08:47:29 -0600, Lostgallifreyan
wrote: Roy Lewallen wrote in m: Lostgallifreyan wrote: Roy Lewallen wrote in : If there was a "best" cable, there would be only one type. Some have lower loss, some are more flexible, some have better weather resistance, some have better shielding, some have a longer lifetime, some tolerate temperature extremes better, some are more uniform, some are less expensive, and so forth. So deciding which cable is "better" requires a lot more information about what your requirements are. If I went into most places selling cables I'd get laughed at if I took that line, However he gave you the right answer to the question you asked. There is no one best coax! Are you just using it for receiving or transmitting as well. Typically you don't find either of those cables used in ham stations, except to feed Beverage receiving antennas. I use a lot of "flooded" RG-6 with compression connectors for UHF receiving. I use RG-8X (foil with shield) to the 40 meter, half wave sloping dipoles. It's fairly rugged, very flexible, presents a low profile to the wind and doesn't weight a lot. Its power handeling capability is a bit low, but I haven't blown any out...yet, unlike CNT-240. they'd say 'hie me to a research lab, if not an actual nunnery'. ![]() Then perhaps you should purchase coax elsewhere? Not that you're wrong, but if you want a single general purpose cable for HF and VHF especially if stocking it for general sale, then there IS a 'best' cable, defined simply by that which most likely serves the wide range of purposes at a low price. Currently in the UK that cable seems to be RG6; few places like to stock more than one type for RF if they think one will do. . . I take it then that this is not for an amateur radio station? Sounds like you have your answer, then. Roy Lewallen, W7EL Yes, if I was using for UHF and perhaps VHF as they sell it for. But as far as I know the older UG59 used a braid with better physical coverage and was specified for HF as well. I'd rather get something this time that has good HF shielding as priority, so I'm not convinced that RG6 is the right choice. A bit of extra loss isn't as bad as poor shielding. RG-6 is foil plus braid and it doesn't get much better than that. However for HF my choice would be RG-8X (with foil plus braid- it comes in many forms) although I use LMR-600. Good luck, Roger (K8RI) |
#8
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On Thu, 25 Mar 2010 02:36:46 -0400, Roger
wrote: On Sun, 31 Jan 2010 08:47:29 -0600, Lostgallifreyan wrote: Roy Lewallen wrote in om: Lostgallifreyan wrote: Roy Lewallen wrote in : If there was a "best" cable, there would be only one type. Some have lower loss, some are more flexible, some have better weather resistance, some have better shielding, some have a longer lifetime, some tolerate temperature extremes better, some are more uniform, some are less expensive, and so forth. So deciding which cable is "better" requires a lot more information about what your requirements are. If I went into most places selling cables I'd get laughed at if I took that line, However he gave you the right answer to the question you asked. There is no one best coax! Are you just using it for receiving or transmitting as well. Typically you don't find either of those cables used in ham stations, except to feed Beverage receiving antennas. I use a lot of "flooded" RG-6 with compression connectors for UHF receiving. I use RG-8X (foil with shield) to the 40 meter, half wave sloping dipoles. It's fairly rugged, very flexible, presents a low profile to the wind and doesn't weight a lot. Its power handeling capability is a bit low, but I haven't blown any out...yet, unlike CNT-240. they'd say 'hie me to a research lab, if not an actual nunnery'. ![]() Then perhaps you should purchase coax elsewhere? Not that you're wrong, but if you want a single general purpose cable for HF and VHF especially if stocking it for general sale, then there IS a 'best' cable, defined simply by that which most likely serves the wide range of purposes at a low price. Currently in the UK that cable seems to be RG6; few places like to stock more than one type for RF if they think one will do. . . I take it then that this is not for an amateur radio station? Sounds like you have your answer, then. Roy Lewallen, W7EL Yes, if I was using for UHF and perhaps VHF as they sell it for. But as far as I know the older UG59 used a braid with better physical coverage and was specified for HF as well. I'd rather get something this time that has good HF shielding as priority, so I'm not convinced that RG6 is the right choice. A bit of extra loss isn't as bad as poor shielding. RG-6 is foil plus braid and it doesn't get much better than that. However for HF my choice would be RG-8X (with foil plus braid- it comes in many forms) although I use LMR-600. Good luck, Roger (K8RI) I use whatever cheap **** Radio Shack has on sale. DXCC 5BWAS |
#9
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Kickin' Ass and Takin' Names wrote:
I use whatever cheap **** Radio Shack has on sale. You might try their coax too! - 73 de Mike N3LI - |
#10
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![]() If I went into most places selling cables I'd get laughed at if I took that line, they'd say 'hie me to a research lab, if not an actual nunnery'. ![]() that you're wrong, but if you want a single general purpose cable for HF and VHF especially if stocking it for general sale, then there IS a 'best' cable, defined simply by that which most likely serves the wide range of purposes at a low price. Currently in the UK that cable seems to be RG6; few places like to stock more than one type for RF if they think one will do. Perfectionism is NOT the first base. It's reasonable to expect some standard without being told to either become an expert or use a bell wire and stay in ignorance. RG6 works, but they sell it for VHF/UHF, not RF. I'm not so concerned with moderate losses, but SNR maintained by good shielding matters to me. You seem to miss the point that one shop's RG6 (or most other RG cables) may well not be the same as another's. So there is no definitive answer to you question. It is also very unlikely that 'good shielding' will have any effect on SNR in most applications, other than due to increased loss if the braiding is very very poor, or you are running the cable very close to a source of broadband interference. Jeff |