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Stacking Winegard HD-6065P antennas
In message , Jerry Stuckle
writes On 1/11/2014 3:44 AM, Ian Jackson wrote: In message , Jerry Stuckle writes The best (and the ones we use) compress the entire base of the connector evenly, creating a smooth crimp. The end of the coax is evenly covered by the connector. In the CATV industry, for F-connectors, isn't Snap-n-Seal now de the norm? Maybe for cable companies who are trying to be cheap. But the professional integrators around here all use crimp-on. Not much more expensive and saving one callback pays for a lot of connectors. Snap-n-Seal certainly isn't trying to be cheap. https://www.google.co.uk/#q=snap+and+seal They enable an essentially watertight seal to be obtained without distorting (or even scratching) the connector, and therefore have little measurable effect on the impedance. -- Ian |
Stacking Winegard HD-6065P antennas
On 1/11/2014 10:25 AM, Ian Jackson wrote:
In message , Jerry Stuckle writes On 1/11/2014 3:44 AM, Ian Jackson wrote: In message , Jerry Stuckle writes The best (and the ones we use) compress the entire base of the connector evenly, creating a smooth crimp. The end of the coax is evenly covered by the connector. In the CATV industry, for F-connectors, isn't Snap-n-Seal now de the norm? Maybe for cable companies who are trying to be cheap. But the professional integrators around here all use crimp-on. Not much more expensive and saving one callback pays for a lot of connectors. Snap-n-Seal certainly isn't trying to be cheap. https://www.google.co.uk/#q=snap+and+seal They enable an essentially watertight seal to be obtained without distorting (or even scratching) the connector, and therefore have little measurable effect on the impedance. That's their claim, anyway. As I said - none of the professional integrators around here use it. The distributors don't even carry it. -- ================== Remove the "x" from my email address Jerry Stuckle JDS Computer Training Corp. ================== |
Stacking Winegard HD-6065P antennas
In message , Jerry Stuckle
writes On 1/11/2014 10:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes On 1/11/2014 3:44 AM, Ian Jackson wrote: In message , Jerry Stuckle writes The best (and the ones we use) compress the entire base of the connector evenly, creating a smooth crimp. The end of the coax is evenly covered by the connector. In the CATV industry, for F-connectors, isn't Snap-n-Seal now de the norm? Maybe for cable companies who are trying to be cheap. But the professional integrators around here all use crimp-on. Not much more expensive and saving one callback pays for a lot of connectors. Snap-n-Seal certainly isn't trying to be cheap. https://www.google.co.uk/#q=snap+and+seal They enable an essentially watertight seal to be obtained without distorting (or even scratching) the connector, and therefore have little measurable effect on the impedance. That's their claim, anyway. And they are true! As I said - none of the professional integrators around here use it "Professional integrators" covers a multitude of sins. Professional in what field? . The distributors don't even carry it. I suppose it depends which distributors you use. Such connectors are hardly unknown in the USA. www.tnb.com/pubint/docs/snapnseal.pdf In the UK cable TV industry, for most applications, it would be a hanging offence not to use an approved Snap-N-Seal connector. -- Ian |
Stacking Winegard HD-6065P antennas
On 1/11/2014 11:08 AM, Ian Jackson wrote:
In message , Jerry Stuckle writes On 1/11/2014 10:25 AM, Ian Jackson wrote: In message , Jerry Stuckle writes On 1/11/2014 3:44 AM, Ian Jackson wrote: In message , Jerry Stuckle writes The best (and the ones we use) compress the entire base of the connector evenly, creating a smooth crimp. The end of the coax is evenly covered by the connector. In the CATV industry, for F-connectors, isn't Snap-n-Seal now de the norm? Maybe for cable companies who are trying to be cheap. But the professional integrators around here all use crimp-on. Not much more expensive and saving one callback pays for a lot of connectors. Snap-n-Seal certainly isn't trying to be cheap. https://www.google.co.uk/#q=snap+and+seal They enable an essentially watertight seal to be obtained without distorting (or even scratching) the connector, and therefore have little measurable effect on the impedance. That's their claim, anyway. And they are true! That is their claim, anyway. As I said - none of the professional integrators around here use it "Professional integrators" covers a multitude of sins. Professional in what field? No, there is only one field of "Professional Integration". It covers everything from CCTV to security to automation systems to theaters (home and commercial). Residential, commercial, and anything in between. . The distributors don't even carry it. I suppose it depends which distributors you use. Such connectors are hardly unknown in the USA. www.tnb.com/pubint/docs/snapnseal.pdf In the UK cable TV industry, for most applications, it would be a hanging offence not to use an approved Snap-N-Seal connector. I didn't say they were unknown. Just that professional integrators (including us) use better quality connectors. And BTW, I checked with a couple of other integrator friends today. They've never seen the cable companies around here use them, either. In fact, the only place they've seen them used is by hobbyists and other consumers. No professionals. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Stacking Winegard HD-6065P antennas
On 1/11/2014 11:33 AM, Jeff wrote:
On 11/01/2014 14:12, Jerry Stuckle wrote: On 1/11/2014 5:24 AM, Jeff wrote: As for handling more power - rubbish. The current in 75 ohm coax is lower than that in 50 ohm coax, for the same power rating. Can you not see the stupidity if that remark??? Jeff It is perfectly true. P=I^2xR. As R increases, I MUST decrease to handle the same power. And since current is the limiting factor in wire, you don't need as large a gauge of wire to handle more power. You really should learn what you're talking about before opening your "mouth". You only continue to show your ignorance. Perhaps you should actually look at the theory of coax transmission lines. If you did you would find that the optimum impedance for max power handling peaks at about 30 ohms and falls away either side of that impedance, 50 ohms being better than 75 ohms. It is a little more complicated than just Ohms Law. It would appear that it is you who are showing their ignorance, and inability to even look at the article that was linked in post that you were replying to!!! http://www.belden.com/blog/broadcastav/50-Ohms-The-Forgotten-Impedance.cfm Jeff Try again. I had it back in college in the early 70's (as an EE major), and I don't think the laws of physics have changed. And the best impedance for a coax is that which matches the input and output impedance of the system, or if the input and output are of different impedances, acts as a matching stub between the two. And yes, I read the article. But you obviously don't understand it. The 30 ohms they are talking about was for ONE SPECIFIC REQUIREMENT. That does NOT mean it is true in different situations. I suggest you learn what you're talking about before you make yourself look even sillier. - ================== Remove the "x" from my email address Jerry, AI0K ================== |
Stacking Winegard HD-6065P antennas
On Sat, 11 Jan 2014 19:41:20 -0500, Jerry Stuckle
wrote: I didn't say they were unknown. Just that professional integrators (including us) use better quality connectors. Could I trouble you for a photo or part number for the crimp type F connectors that you are using? I want to see what I'm missing. Incidentally, SCTE IPS-TP-401 specifies that F connectors should survive a 40 lb pull test. http://www.sbcatest.com/SBCA%20connector%20recommended%20practices.pdf I once built a fixture for testing this. Many of the cheap connectors that I randomly purchased on eBay failed the test. You might want to try it with your crimp connectors. And BTW, I checked with a couple of other integrator friends today. They've never seen the cable companies around here use them, either. In fact, the only place they've seen them used is by hobbyists and other consumers. No professionals. Once a year, CED Magazine[1] provides an F-connector cross reference wall chart. Here's the one for 2011. I don't recall seeing one in the past 2 years probably because the incompatibility problems have finally stabilized: http://www.cedmagazine.com/wallcharts/2011/10/f-connector-cross-reference-chart-2011 http://www.cedmagazine.com/sites/cedmagazine.com/files/Wall_Charts/1111_F-Cconnector-WC.pdf If you inspect the chart, you'll see the various SNS Snap-n-Seal part numbers. The advertisement in the lower right is for Belden/T&B SNS connectors. What I guess(tm) happened was prior to Belden purchasing Thomas and Betts in 2010, T&B had no interest in producing a connector that would work with all RG-6/u type cables. Having many different types means everyone has to carry a larger inventory. I'm too lazy to check, but my bin contains at least 4 different F plugs for various manufacturers cables and shield types of RG-6/u. I use the above chart to make sure I don't create a mismatch. The most common connector is the SNS1P6 LRC series, color coded "blue", which fits double shielded RG-6/u. http://www.tnb.com/pubint/docs/snapnseal.pdf (11 MBytes) http://www.youtube.com/watch?v=wBZAHhH4wCo (2 min) Immediately after the acquisition, Belden introduced the "red" connector, which is a universal replacement for most of the others and will fit double, triple, and quad shielded RG-6/u. My experience with this connector hase been quite good. However, I continue to use the "blue" for double shielded RG-6/u because I have about a years inventory of connectors left. When I reorder, it will probably be the universal (or ultimate) "red" type in cool looking nickel-tin plating. Locally, Comcast and Charter both use various types of T&B Snap-and-Seal connectors. I had Comcast install cable internet in our office building. That's all that I saw in use. In older installations, they use Augat LRC connectors, which are the predecessor of the current Belden/T&B connectors. You also mentioned compression and stripping tools. I have about 5 of them, ranging from cheap eBay junk to the T&B IT1000 which sells for about $100: http://www.mjsales.net/itemsearch.asp?FamilyID=202 The IT1000 seems to work best, although some odd extra long compression connectors, or the BNC or Phono compression connectors, require a different tool. I also stupidly bought a compression tool that only fits one manufacturers connectors, and none other. Most of my ham antennas use a compression BNC connector and/or F-connector to UHF or BNC adapter. My IT1000 is marked Augat LRC, which should give a clue as to its age. You also mentioned that you're using RG-59/u. Please note that RG-59/u lacks the foil shield(s) of RG-6/u which means that it leaks more and suffers from possible ingres problems. RG-59/u has higher attenuation: RG-59 RG-6 50 MHz 2.4 dB 1.5 dB 100 MHz 3.4 dB 2.0 dB 400 MHz 7.0 dB 4.3 dB 900 MHz 11.1 dB 6.8 dB 1000 MHz 12.0 dB 7.0 dB I've purged RG-59/u from my life many years ago. Are you sure you want to continue using the stuff. Not all RG-6/u cables are equal. Here's some junk: http://sewelldirect.com/RG6-Bulk-Cable-Black-60-Braided-1000ft-Spool.asp RG-6/u with no foil shield and only 60% coverage. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Stacking Winegard HD-6065P antennas
On Fri, 10 Jan 2014 22:55:41 -0500, Jerry Stuckle
wrote: That's theoretical. Reality is much different. I think I'll print that on a large piece of paper and have it framed for my office wall. Have you ever worked with a TDR? It's one of the tools we use regularly (and an expensive one, also). Sure. Also OTDR for fiber. I don't use the expensive stuff, unless you include the Acterna HST3000 tester that was stolen from my office a few years ago. Mostly, I built my own using a pulse generator and an oscilloscope. You stated that the losses come primarily from the "impedance bump" presumably produced by the non-50 ohm connector or adapter in the line. Well, time to put that to the test. 1. Take a length of RG-6/u coax with good connectors. Apply signal on one end from a generator. Measure the signal level on the other end with a spectrum analyzer that has a 1dB per division scale. I want to be able to see small changes. 2. After establishing a reference level, either beat on the coax cable with a hammer, squash it with a C-clamp, or flatten it with a bench vise. Squash it just enough to obtain an "impedance bump", but not a short between the center conductor and shield. Note the change in level, if you can see it. 3. Now, either un-squash the cable, or find another length of RG-6/u and attach a TDR. It can be open, shorted, or terminated. Doesn't matter. 4. Flatten the cable in the same manner as before and note the TDR display. What I expect that you'll see is that there will be almost no change in attenuation, while the TDR display will show a rather radical "impedance bump". That's because the only thing that the change in impedance along the cable length can do is create reflections. Those are a serious problem in a CATV system, but really don't involve serious signal level losses. That's theoretical. Reality is much the same. So? Dipoles aren't 50 ohm antennas. They're typically closer to 75 ohm. I guess you missed my point. If you can tolerate the 1.5:1 VSWR, the reduced attenuation and cost of 75 ohm coax makes the effort worthwhile. As for handling more power - rubbish. The current in 75 ohm coax is lower than that in 50 ohm coax, for the same power rating. Please re-read the article: www.belden.com/blog/broadcastav/50-Ohms-The-Forgotten-Impedance.cfm http://www.microwaves101.com/encyclopedia/why50ohms.cfm We use RG-59 where appropriate, like from an outlet to the set top box. But our in-wall coax runs are all RG-6 quad-shielded. RG-59/u doesn't have a foil shield, so it's more flexible. So, I guess that might work. For short lengths, the increased leakage, higher ingress, and higher attenuation can probably be tolerated. However, I use extra long RG-6/u, which somewhat compensates for the lack of flexibility. But we're also doing less and less coax and more and more Category cable nowadays. No MoCA installations? http://www.mocalliance.org They're OK for the hobbyist, but I don't know of any professionals who use them. In fact, checking our main wholesalers, they aren't even available through them (but other Beldon products are). Find a different distributor or ask for it by part number. Thomas and Betts SNS1P6U. Quick check: Stocked by Allied, Newark, Tessco, Farnel(UK), MCM. Not stocked by Digikey, Mouser, Arrow. T&B distributor search: http://www.tnb.com/ps/dls/dls?ca=corp -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Stacking Winegard HD-6065P antennas
On 1/11/2014 11:51 PM, Jeff Liebermann wrote:
On Sat, 11 Jan 2014 19:41:20 -0500, Jerry Stuckle wrote: I didn't say they were unknown. Just that professional integrators (including us) use better quality connectors. Could I trouble you for a photo or part number for the crimp type F connectors that you are using? I want to see what I'm missing. I can't post an image to the list, and distributors websites require logins. It won't do you any good anyway - you won't find them on ebay and the link. Sale is restricted by the manufacturers to professionals. Incidentally, SCTE IPS-TP-401 specifies that F connectors should survive a 40 lb pull test. http://www.sbcatest.com/SBCA%20connector%20recommended%20practices.pdf I once built a fixture for testing this. Many of the cheap connectors that I randomly purchased on eBay failed the test. You might want to try it with your crimp connectors. They meet all requirements. These are not cheap connectors you find on ebay. And BTW, I checked with a couple of other integrator friends today. They've never seen the cable companies around here use them, either. In fact, the only place they've seen them used is by hobbyists and other consumers. No professionals. Once a year, CED Magazine[1] provides an F-connector cross reference wall chart. Here's the one for 2011. I don't recall seeing one in the past 2 years probably because the incompatibility problems have finally stabilized: http://www.cedmagazine.com/wallcharts/2011/10/f-connector-cross-reference-chart-2011 http://www.cedmagazine.com/sites/cedmagazine.com/files/Wall_Charts/1111_F-Cconnector-WC.pdf If you inspect the chart, you'll see the various SNS Snap-n-Seal part numbers. The advertisement in the lower right is for Belden/T&B SNS connectors. None of them are used by professionals over here. What I guess(tm) happened was prior to Belden purchasing Thomas and Betts in 2010, T&B had no interest in producing a connector that would work with all RG-6/u type cables. Having many different types means everyone has to carry a larger inventory. I'm too lazy to check, but my bin contains at least 4 different F plugs for various manufacturers cables and shield types of RG-6/u. I use the above chart to make sure I don't create a mismatch. The most common connector is the SNS1P6 LRC series, color coded "blue", which fits double shielded RG-6/u. http://www.tnb.com/pubint/docs/snapnseal.pdf (11 MBytes) http://www.youtube.com/watch?v=wBZAHhH4wCo (2 min) Immediately after the acquisition, Belden introduced the "red" connector, which is a universal replacement for most of the others and will fit double, triple, and quad shielded RG-6/u. My experience with this connector hase been quite good. However, I continue to use the "blue" for double shielded RG-6/u because I have about a years inventory of connectors left. When I reorder, it will probably be the universal (or ultimate) "red" type in cool looking nickel-tin plating. Belden makes great cables, but as a whole the industry has not embraced them. The major distributors don't even carry the connectors (my guess would be due to lack of sales). And you can't use one connector for different sizes of coax without causing an impedance bump and/or having mechanical issues. The connectors we use are all for RG-6 quad (we do not use less). Locally, Comcast and Charter both use various types of T&B Snap-and-Seal connectors. I had Comcast install cable internet in our office building. That's all that I saw in use. In older installations, they use Augat LRC connectors, which are the predecessor of the current Belden/T&B connectors. I haven't seen Comcast recently, but the last I looked they didn't use Snap & Seal connectors. I haven't seen it recently because people around here don't let Comcast wire their buildings. They hire companies like ours to do it. You also mentioned compression and stripping tools. I have about 5 of them, ranging from cheap eBay junk to the T&B IT1000 which sells for about $100: http://www.mjsales.net/itemsearch.asp?FamilyID=202 The IT1000 seems to work best, although some odd extra long compression connectors, or the BNC or Phono compression connectors, require a different tool. I also stupidly bought a compression tool that only fits one manufacturers connectors, and none other. Most of my ham antennas use a compression BNC connector and/or F-connector to UHF or BNC adapter. My IT1000 is marked Augat LRC, which should give a clue as to its age. You also mentioned that you're using RG-59/u. Please note that RG-59/u lacks the foil shield(s) of RG-6/u which means that it leaks more and suffers from possible ingres problems. RG-59/u has higher attenuation: RG-59 RG-6 50 MHz 2.4 dB 1.5 dB 100 MHz 3.4 dB 2.0 dB 400 MHz 7.0 dB 4.3 dB 900 MHz 11.1 dB 6.8 dB 1000 MHz 12.0 dB 7.0 dB I've purged RG-59/u from my life many years ago. Are you sure you want to continue using the stuff. We know what we're doing. You don't know anything about our installations, our customers or our needs. Don't try to tell someone who has done this professionally for years what they should be using. And you're trying to tell EVERY professional in the United States they're doing their job wrong. We all use RG-59 at times. RG-6 is NOT appropriate for everything. Not all RG-6/u cables are equal. Here's some junk: http://sewelldirect.com/RG6-Bulk-Cable-Black-60-Braided-1000ft-Spool.asp RG-6/u with no foil shield and only 60% coverage. We know what is good and what is not. You don't need to tell us our job. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Stacking Winegard HD-6065P antennas
On 1/12/2014 5:51 AM, Jeff wrote:
Jeff Try again. I had it back in college in the early 70's (as an EE major), and I don't think the laws of physics have changed. And the best impedance for a coax is that which matches the input and output impedance of the system, or if the input and output are of different impedances, acts as a matching stub between the two. And yes, I read the article. But you obviously don't understand it. The 30 ohms they are talking about was for ONE SPECIFIC REQUIREMENT. That does NOT mean it is true in different situations. I suggest you learn what you're talking about before you make yourself look even sillier. Well let me think; who am I doing to believe; text books on transmission line theory, data sheets for coax cables, and an article by well respected cable manufacturer), or your personal (and incorrect) theory?? Perhaps you should also point out to Belden that their article is wrong as well!! If you think that sending power over a matched cable is a specific requirement then you obviously do not understand the article. Jeff I go by my textbooks and professors. I don't believe someone who read an article about a specific installation and tried to apply that to the entire world. And I didn't say their article was wrong. I said YOUR APPLICATION of what the article said is wrong. Two entirely different things. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Stacking Winegard HD-6065P antennas
On 1/12/2014 12:29 AM, Jeff Liebermann wrote:
On Fri, 10 Jan 2014 22:55:41 -0500, Jerry Stuckle wrote: That's theoretical. Reality is much different. I think I'll print that on a large piece of paper and have it framed for my office wall. Have you ever worked with a TDR? It's one of the tools we use regularly (and an expensive one, also). Sure. Also OTDR for fiber. I don't use the expensive stuff, unless you include the Acterna HST3000 tester that was stolen from my office a few years ago. Mostly, I built my own using a pulse generator and an oscilloscope. I'm not talking about fiber, and I'm not talking about some half-assed gadget cooked up in your basement. I'm talking about a real, professional-grade TDR. We use expensive stuff because it gives accurate results. You stated that the losses come primarily from the "impedance bump" presumably produced by the non-50 ohm connector or adapter in the line. Well, time to put that to the test. I didn't say anything about a non-50 ohm connector. The connector can be 50 ohm and still get an impedance bump. With a TDR you can see every connector on the cable (as long as they are far enough apart - typically 3-4 feet). 1. Take a length of RG-6/u coax with good connectors. Apply signal on one end from a generator. Measure the signal level on the other end with a spectrum analyzer that has a 1dB per division scale. I want to be able to see small changes. 2. After establishing a reference level, either beat on the coax cable with a hammer, squash it with a C-clamp, or flatten it with a bench vise. Squash it just enough to obtain an "impedance bump", but not a short between the center conductor and shield. Note the change in level, if you can see it. 3. Now, either un-squash the cable, or find another length of RG-6/u and attach a TDR. It can be open, shorted, or terminated. Doesn't matter. 4. Flatten the cable in the same manner as before and note the TDR display. What I expect that you'll see is that there will be almost no change in attenuation, while the TDR display will show a rather radical "impedance bump". That's because the only thing that the change in impedance along the cable length can do is create reflections. Those are a serious problem in a CATV system, but really don't involve serious signal level losses. That's theoretical. Reality is much the same. First of all, we don't crush cables to try to emulate something we can easily see in real life. Second of all, you can gimmick up something all you want with signal generators, spectrum analyzers, crushed cables, all you want. We SEE the results in real time in real installations with the appropriate test equipment. So? Dipoles aren't 50 ohm antennas. They're typically closer to 75 ohm. I guess you missed my point. If you can tolerate the 1.5:1 VSWR, the reduced attenuation and cost of 75 ohm coax makes the effort worthwhile. No, it's worthwhile because your coax will more closely match the antenna. And you can easily match the coax to the transmitter with a tuner. As for handling more power - rubbish. The current in 75 ohm coax is lower than that in 50 ohm coax, for the same power rating. Please re-read the article: www.belden.com/blog/broadcastav/50-Ohms-The-Forgotten-Impedance.cfm http://www.microwaves101.com/encyclopedia/why50ohms.cfm I read the article. Unlike you, I understand what it is saying. We use RG-59 where appropriate, like from an outlet to the set top box. But our in-wall coax runs are all RG-6 quad-shielded. RG-59/u doesn't have a foil shield, so it's more flexible. So, I guess that might work. For short lengths, the increased leakage, higher ingress, and higher attenuation can probably be tolerated. However, I use extra long RG-6/u, which somewhat compensates for the lack of flexibility. You don't know our installations. We've been in business for several years, with lots of satisfied customers. Trying to tell a professional what their job is only makes you look stupid. But we're also doing less and less coax and more and more Category cable nowadays. No MoCA installations? http://www.mocalliance.org Nope. It's used by few professionals. Coax ends up with too many problems. Category cable for runs under 100M or so and fiber for longer runs. They're OK for the hobbyist, but I don't know of any professionals who use them. In fact, checking our main wholesalers, they aren't even available through them (but other Beldon products are). Find a different distributor or ask for it by part number. Thomas and Betts SNS1P6U. We use several distributors - both U.S. and international companies. Quick check: Stocked by Allied, Newark, Tessco, Farnel(UK), MCM. Not stocked by Digikey, Mouser, Arrow. T&B distributor search: http://www.tnb.com/ps/dls/dls?ca=corp These are consumer (retail) outlets. They are not used by most professionals. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
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