Which is it, RG59 or RG6?
in [Repair]
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From: mm on 5 Dec 2009 16:44 I hope you guys can help me again. I gather from posts here that RG6 is better than RG59, is that right? Could the use of of RG59, 33 feet, for at least one tv be responsible for my bad reception on that tv? I'm using co-ax for distributing tv from my DVDR to TVs throughout the house. (The DVDR tunes in the over-the-air digital signal and I have an RF modulator to change the DVDR output to analog. I did the wiring to the tvs 25 years ago, and I used left-over and scrap co-ax, so the co-ax is older than 25 years. Did they have RG-6 25 or 30 years ago? I didn't pay attention then so I don't know what most of it is, but the 33 foot piece going to this one tv is RMS Electonics Inc. 59/U. Everything was fine until the digital conversion, and now this tv that I watch a lot shows a grainy picture. All the other tvs have great pictures, and even for this one, when I supply a signal directly from a set-top digital converter box, only 3 feet of cable, it shows a perfect picture**. Do you think replacing the RG59 with RG6 will get me the perfect picture other sets get? I didn't use home-runs, just splitters and every two splitters a signal amp, a total of three signal amps, one with 2 or 4 outputs, and two with 2. Would an additional signal amp at the start of the RG-59 also give me perfect or at least improved reception? **(But the set-top box isn't connected to the main antenna and doesn't get several stations I watch, nor will it play what is recorded on the DVDR.)
From: David on 5 Dec 2009 16:52 "mm" <NOPSAMmm2005(a)bigfoot.com> wrote in message news:umhlh5lcjgr1ldqmb7up677fuoe7qpug09(a)4ax.com... > I hope you guys can help me again. > > I gather from posts here that RG6 is better than RG59, is > that right? > > Could the use of of RG59, 33 feet, for at least one tv be > responsible > for my bad reception on that tv? > > I'm using co-ax for distributing tv from my DVDR to TVs > throughout the > house. (The DVDR tunes in the over-the-air digital signal > and I have > an RF modulator to change the DVDR output to analog. I > did the wiring > to the tvs 25 years ago, and I used left-over and scrap > co-ax, so the > co-ax is older than 25 years. Did they have RG-6 25 or 30 > years ago? > I didn't pay attention then so I don't know what most of > it is, but > the 33 foot piece going to this one tv is RMS Electonics > Inc. 59/U. > > Everything was fine until the digital conversion, and now > this tv that > I watch a lot shows a grainy picture. All the other tvs > have great > pictures, and even for this one, when I supply a signal > directly from > a set-top digital converter box, only 3 feet of cable, it > shows a > perfect picture**. > > Do you think replacing the RG59 with RG6 will get me the > perfect > picture other sets get? I didn't use home-runs, just > splitters and > every two splitters a signal amp, a total of three signal > amps, one > with 2 or 4 outputs, and two with 2. Would an additional > signal amp > at the start of the RG-59 also give me perfect or at least > improved > reception? > > **(But the set-top box isn't connected to the main antenna > and > doesn't get several stations I watch, nor will it play > what is > recorded on the DVDR.) Yes RG6 existed 25 years ago. You have something else wrong. The difference in loss between 33 feet of RG59 vs. RG6 is negligible at VHF and at most a few dB at the higher UHF frequencies. What else is in that 33 foot span? David
From: mm on 5 Dec 2009 17:31 On Sat, 5 Dec 2009 15:52:16 -0600, "David" <someone(a)somewhere.com> wrote: > > >"mm" <NOPSAMmm2005(a)bigfoot.com> wrote in message >news:umhlh5lcjgr1ldqmb7up677fuoe7qpug09(a)4ax.com... >> I hope you guys can help me again. >> >> I gather from posts here that RG6 is better than RG59, is >> that right? >> >> Could the use of of RG59, 33 feet, for at least one tv be >> responsible for my bad reception on that tv? >> >> I'm using co-ax for distributing tv from my DVDR to TVs >> throughout the >> house. (The DVDR tunes in the over-the-air digital signal >> and I have >> an RF modulator to change the DVDR output to analog. I >> did the wiring >> to the tvs 25 years ago, and I used left-over and scrap >> co-ax, so the >> co-ax is older than 25 years. Did they have RG-6 25 or 30 >> years ago? >> I didn't pay attention then so I don't know what most of >> it is, but >> the 33 foot piece going to this one tv is RMS Electonics >> Inc. 59/U. >> >> Everything was fine until the digital conversion, and now >> this tv that >> I watch a lot shows a grainy picture. All the other tvs >> have great >> pictures, and even for this one, when I supply a signal >> directly from >> a set-top digital converter box, only 3 feet of cable, it >> shows a perfect picture**. >> >> Do you think replacing the RG59 with RG6 will get me the >> perfect >> picture other sets get? I didn't use home-runs, just >> splitters and >> every two splitters a signal amp, a total of three signal >> amps, one >> with 2 or 4 outputs, and two with 2. Would an additional >> signal amp >> at the start of the RG-59 also give me perfect or at least >> improved reception? BTW, I'm using an A/B switch now. I had this problem when I was connected directly, but is there any point in getting a gold-plated A/B switch? >Yes RG6 existed 25 years ago. You have something else wrong. >The difference in loss between 33 feet of RG59 vs. RG6 is >negligible at VHF and at most a few dB at the higher UHF >frequencies. What else is in that 33 foot span? It's in the attic. About two feet away are two four-inch galvanized sheet metal tubes/ducts that the bathroom fans use to blow air out of the bathroom to the crest of the roof, but the fans are never on. The cable doesn't go by any electric wires because the bedrooms were built without ceiling lights. The bathroom ceiling light is maybe only two feet away but it makes no difference if the light is on or not. There's a 1 to 3 splitter, with one output going to another tv which has a perfect picture, one has a terminator resistor designed for this purpose (in an F connector), and the other output goes to the problem tv. The picture even from analog was perfect on most stations until analog ended, and afaicr that was exactly when this tv picture got grainy. But for fear this was a coincidence, I waited to ask this queestion until I had a different tv to use here. I put that in today, and it too has a grainy picture, even though when it was connected in the basement, it had a smooth, perfect picture. Well, being grainy is the only thing that's not perfect about it, afaic. Besides being grainy, or maybe this is part of what I'm calling graininess, the problem picture has a lot of teeny tiny white dots sometimes just scattered in the picture and sometimes arrayed in dim horizontal and vertical lines, about 5 lines horizontal. and 7 lines vertical. The lines are not that straight and the vert lines move left and right a little bit and the horiz lines up and down a little bit. There also seem to be dots of other colors and sometimes jaggedy dark colored lines. The end result is a picture that's pretty good, by 1970's over-the-air standards, and the darks are darker now than they were in June, but it's not smooth. I can live with this of course, for years if it works out that way, but I like to fix things. >David >
From: Jeff Liebermann on 5 Dec 2009 17:59 On Sat, 05 Dec 2009 16:44:42 -0500, mm <NOPSAMmm2005(a)bigfoot.com> wrote: >I gather from posts here that RG6 is better than RG59, is that right? Yep. RG-6/u is generally better for most everything. >Could the use of of RG59, 33 feet, for at least one tv be responsible >for my bad reception on that tv? If the coax cable is in good shape, hasn't been eaten by rats, mice, squirrels, kids, vacuum cleaners, etc. and has properly attached connectors, then there's almost no difference in performance between RG-59 and RG-6/u. In my limited experience, lousy connector crimping and mouse eaten cables are the usual culprits. >I'm using co-ax for distributing tv from my DVDR to TVs throughout the >house. (The DVDR tunes in the over-the-air digital signal and I have >an RF modulator to change the DVDR output to analog. You must enjoy low quality video. It appears that you're also using that derrangement to move audio, so the analog video is really NTSC encoded with an approximately 4MHz maximum bandwidth. If all you have is an analog TV, that's fine and will work, but if you're watching this on a digital capable TV, it's wasting the capabilities of the TV. Incidentally, thanks for leaving out all the make and model numbers, as well as most of the numbers. That adds some credibility to my guess work. If you want help with your SPECIFIC problem, it helps to supply some specifics as to what manner or video problem you're seeing and what manner of hardware you have to work with. >I did the wiring >to the tvs 25 years ago, and I used left-over and scrap co-ax, so the >co-ax is older than 25 years. Ok, the coax is suspect. This is easier to troubleshoot by substitution. Find a 50ft piece of decent 75 ohm coax cable. Run it in place of the suspected 33ft piece. If it magically fixes the problem, your old coax is history. Also, if you have a scope and are interested in building a TDR (time domain reflectometer), you can test the cable. <http://en.wikipedia.org/wiki/Time-domain_reflectometer> <http://www.epanorama.net/circuits/tdr.html> >Did they have RG-6 25 or 30 years ago? Oh yes. It was in the original military "radio guide" MIL-HDBK-216 from WWII. The "6" means page 6 of the guide. >I didn't pay attention then so I don't know what most of it is, but >the 33 foot piece going to this one tv is RMS Electonics Inc. 59/U. > >Everything was fine until the digital conversion, and now this tv that >I watch a lot shows a grainy picture. All the other tvs have great >pictures, and even for this one, when I supply a signal directly from >a set-top digital converter box, only 3 feet of cable, it shows a >perfect picture**. I guess "grainy" means you're getting a weak signal. Well, drag one of your other TV's over to this location and see if it's a consistent problem. If the 2nd TV is also "grainy", then you probably have a low signal level for some reason. Again, it can be the cable or the connectors. A broken shield connection will still deliver a signal, but at somewhat lower level. Also, substitute the coax with a known good one as I previously suggested. >Do you think replacing the RG59 with RG6 will get me the perfect >picture other sets get? Dunno. I would find the cause of the problem before ripping out the cable. However, if it's easy to get to and doesn't make too big a mess, it's worth a try. Either RG-59 or RG-6/u will work as you're only using it on Channel 2 or 3 with the RF modulator. However, if you were going to shovel the entired TV spectrum, from VHF to the top of UHF through the cable, as you will if replace your analog TV with a DTV, then I would use RG-6/u. >I didn't use home-runs, just splitters and >every two splitters a signal amp, a total of three signal amps, one >with 2 or 4 outputs, and two with 2. Holdit. Any one of these can be the problem. That includes amplifiers and splitters with unterminated outputs. First, you don't really need all those amplifiers. Most TV's can easily handle one or two 2 or 4 way splitters, without an amplifier. However, I have no clue how much RF output your unspecified RF modulator belches or what your amplfiers are doing. I also can't guess your topology (wiring layout). My guess(tm) is that you have too many amplifiers or one of them is unplugged or dead. Try replacing the amps with an ordinary 2 way or 4 way splitter and see if it magically fixes the problem. Also, if you don't have a CATV signal level meter, walk the TV around to the various amps until the bad section or amplifier is found. If you have any unterminated outputs, kindly terminate them with a 75 ohm terminator. >Would an additional signal amp >at the start of the RG-59 also give me perfect or at least improved >reception? No. You already have too many amplifiers. You'll do better by getting rid of amps or at least finding which one is the culprit. It might still be the coax, but I'm more inclined to guess(tm) that one of the amps if fried or sick. > **(But the set-top box isn't connected to the main antenna and >doesn't get several stations I watch, nor will it play what is >recorded on the DVDR.) You lost me. What does this have to do with anything? Draw you topology (wiring) and post it somewhere. Don't forget to include some numbers. -- Jeff Liebermann jeffl(a)cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
From: hr(bob) hofmann on 5 Dec 2009 23:12
On Dec 5, 4:59 pm, Jeff Liebermann <je...(a)cruzio.com> wrote: > On Sat, 05 Dec 2009 16:44:42 -0500, mm <NOPSAMmm2...(a)bigfoot.com> > wrote: > > >I gather from posts here that RG6 is better than RG59, is that right? > > Yep. RG-6/u is generally better for most everything. > > >Could the use of of RG59, 33 feet, for at least one tv be responsible > >for my bad reception on that tv? > > If the coax cable is in good shape, hasn't been eaten by rats, mice, > squirrels, kids, vacuum cleaners, etc. and has properly attached > connectors, then there's almost no difference in performance between > RG-59 and RG-6/u. In my limited experience, lousy connector crimping > and mouse eaten cables are the usual culprits. > > >I'm using co-ax for distributing tv from my DVDR to TVs throughout the > >house. (The DVDR tunes in the over-the-air digital signal and I have > >an RF modulator to change the DVDR output to analog. > > You must enjoy low quality video. It appears that you're also using > that derrangement to move audio, so the analog video is really NTSC > encoded with an approximately 4MHz maximum bandwidth. If all you have > is an analog TV, that's fine and will work, but if you're watching > this on a digital capable TV, it's wasting the capabilities of the TV. > > Incidentally, thanks for leaving out all the make and model numbers, > as well as most of the numbers. That adds some credibility to my > guess work. If you want help with your SPECIFIC problem, it helps to > supply some specifics as to what manner or video problem you're seeing > and what manner of hardware you have to work with. > > >I did the wiring > >to the tvs 25 years ago, and I used left-over and scrap co-ax, so the > >co-ax is older than 25 years. > > Ok, the coax is suspect. This is easier to troubleshoot by > substitution. Find a 50ft piece of decent 75 ohm coax cable. Run it > in place of the suspected 33ft piece. If it magically fixes the > problem, your old coax is history. > > Also, if you have a scope and are interested in building a TDR (time > domain reflectometer), you can test the cable. > <http://en.wikipedia.org/wiki/Time-domain_reflectometer> > <http://www.epanorama.net/circuits/tdr.html> > > >Did they have RG-6 25 or 30 years ago? > > Oh yes. It was in the original military "radio guide" MIL-HDBK-216 > from WWII. The "6" means page 6 of the guide. > > >I didn't pay attention then so I don't know what most of it is, but > >the 33 foot piece going to this one tv is RMS Electonics Inc. 59/U. > > >Everything was fine until the digital conversion, and now this tv that > >I watch a lot shows a grainy picture. All the other tvs have great > >pictures, and even for this one, when I supply a signal directly from > >a set-top digital converter box, only 3 feet of cable, it shows a > >perfect picture**. > > I guess "grainy" means you're getting a weak signal. Well, drag one > of your other TV's over to this location and see if it's a consistent > problem. If the 2nd TV is also "grainy", then you probably have a low > signal level for some reason. Again, it can be the cable or the > connectors. A broken shield connection will still deliver a signal, > but at somewhat lower level. Also, substitute the coax with a known > good one as I previously suggested. > > >Do you think replacing the RG59 with RG6 will get me the perfect > >picture other sets get? > > Dunno. I would find the cause of the problem before ripping out the > cable. However, if it's easy to get to and doesn't make too big a > mess, it's worth a try. Either RG-59 or RG-6/u will work as you're > only using it on Channel 2 or 3 with the RF modulator. > > However, if you were going to shovel the entired TV spectrum, from VHF > to the top of UHF through the cable, as you will if replace your > analog TV with a DTV, then I would use RG-6/u. > > >I didn't use home-runs, just splitters and > >every two splitters a signal amp, a total of three signal amps, one > >with 2 or 4 outputs, and two with 2. > > Holdit. Any one of these can be the problem. That includes > amplifiers and splitters with unterminated outputs. First, you don't > really need all those amplifiers. Most TV's can easily handle one or > two 2 or 4 way splitters, without an amplifier. However, I have no > clue how much RF output your unspecified RF modulator belches or what > your amplfiers are doing. I also can't guess your topology (wiring > layout). My guess(tm) is that you have too many amplifiers or one of > them is unplugged or dead. Try replacing the amps with an ordinary 2 > way or 4 way splitter and see if it magically fixes the problem. Also, > if you don't have a CATV signal level meter, walk the TV around to the > various amps until the bad section or amplifier is found. If you have > any unterminated outputs, kindly terminate them with a 75 ohm > terminator. > > >Would an additional signal amp > >at the start of the RG-59 also give me perfect or at least improved > >reception? > > No. You already have too many amplifiers. You'll do better by > getting rid of amps or at least finding which one is the culprit. It > might still be the coax, but I'm more inclined to guess(tm) that one > of the amps if fried or sick. > > > **(But the set-top box isn't connected to the main antenna and > >doesn't get several stations I watch, nor will it play what is > >recorded on the DVDR.) > > You lost me. What does this have to do with anything? Draw you > topology (wiring) and post it somewhere. Don't forget to include some > numbers. > > -- > Jeff Liebermann je...(a)cruzio.com > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558 Try connecting each set directly by replacing the splitters with thru connectors and see if they all work ok. This will require that you undo and redo a bunch of connections as you check out eachset and associated cables,, but it is the only way to be sure that your basic components are good. I agree with other posters that bad crimp connectios are a frequent problem. A little corrosion aftrer 25 years may make the contact between the outer shield/aluminum ground wire to the connector outer housing intermittent and that can do wonderous things. If the output of the dvr is of typical levels, it should easily drive another set 30 feet away. I have a 3-way splitter on the output of my cable box and it drives the nearby tv as well as two other sets 30 feet away, using a 1-3 splitter, with perfect pictures. |