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![]() "JIMMIE" wrote in message ... On Feb 8, 2:00 pm, amdx wrote: Hi All, I'm on a boat, about 170ft from the utility post. Recently our cable company switched to the wonderful world of Digital TV. I got the new digital converter and had no picture. I took the box back and got a second box, still no picture. So now I suspect a weak signal and confirm that it is the cable length. The cable company came out and gave me a better cable than I had installed. At this point I have a picture but it is intermittent. The signal at the utility post has 3 outputs and had a four way splitter, I suggested the cable guy put in two 2 way splitters and give me the stronger (first) tap. That got my signal to work almost all the time. I'd like to get the signal to work 100% of the time. I don't has access to electricity at the utility post, so an amp is out. Although I could try an amp at the cable box end. Is that reasonable? I would run two cables if there was a way to make it increase signal strength. Getting anymore from the cable company is not an option. Any ideas to get a better signal? Mikek PS. When the signal fails it seems channel 41 is ok and above 42 it breaks up. Curious to know if there is an unusual frequency jump between those two digital channels. Google your cable box model. You should able to find ifo on how to pull up a menu that shows signal strengh. -60dbm is about where my sigal starts droping out Jimmie ================================================== === Yes, but be mindful of the difference between dBm and dBmV. The cable industry often deals in levels on the dBmV scale. There are places like this ... http://www.maxim-ic.com/app-notes/index.mvp/id/808 where you can see some conversion equations. Jimmie's -60dBm equals -11.25 dBmV. Same power level -- different scale. I have long known level requirements for the TV tuner's cousin, the cable modem. The common DOCSIS 2 cable modems are usually spec'ed for -15dBmV to +15dBmV and the smart operators try to keep inside +/- 12. Thus, you can see that Jimmie's -11.25dBmV is near the low limit and that dropouts become more likely in that neighborhood. I little bit of google snooping revealed that DTV cable boxes would like 0dBmV and will usually be okay with -10dBmV to +10dBmV. Almost the same. i hope this helps. "Sal" "Sal" |
#2
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On Feb 9, 6:35*pm, "Sal" wrote:
"JIMMIE" wrote in message ... On Feb 8, 2:00 pm, amdx wrote: Hi All, I'm on a boat, about 170ft from the utility post. Recently our cable company switched to the wonderful world of Digital TV. I got the new digital converter and had no picture. I took the box back and got a second box, still no picture. So now I suspect a weak signal and confirm that it is the cable length. The cable company came out and gave me a better cable than I had installed. At this point I have a picture but it is intermittent. The signal at the utility post has 3 outputs and had a four way splitter, I suggested the cable guy put in two 2 way splitters and give me the stronger (first) tap. That got my signal to work almost all the time. I'd like to get the signal to work 100% of the time. I don't has access to electricity at the utility post, so an amp is out. Although I could try an amp at the cable box end. Is that reasonable? I would run two cables if there was a way to make it increase signal strength. Getting anymore from the cable company is not an option. Any ideas to get a better signal? Mikek PS. When the signal fails it seems channel 41 is ok and above 42 it breaks up. Curious to know if there is an unusual frequency jump between those two digital channels. Google your cable box model. You should able to find ifo on how to pull up a menu that shows signal strengh. -60dbm is about where my sigal starts droping out Jimmie ================================================== === Yes, but be mindful of the difference between dBm and dBmV. * *The cable industry often deals in levels *on the dBmV scale. There are places like this ... http://www.maxim-ic.com/app-notes/index.mvp/id/808 where you can see some conversion equations. *Jimmie's -60dBm equals -11.25 dBmV. Same power level -- different scale. I have long known level requirements for the TV tuner's cousin, the cable modem. *The common DOCSIS 2 cable modems are usually spec'ed for -15dBmV to +15dBmV and the smart operators try to keep inside +/- 12. *Thus, you can see that Jimmie's -11.25dBmV is near the low limit and that dropouts become more likely in that neighborhood. I little bit of google snooping revealed that DTV cable boxes would like 0dBmV and will usually be okay with -10dBmV to +10dBmV. *Almost the same. i hope this helps. "Sal" "Sal"- Hide quoted text - - Show quoted text - Sal, A relative number by any other name would smell as sweet. The reccomendations for my box is about the same but it works well below that at least according to what I measure withe the cable box. BTW it just says 'db'. dBm was an assumption on my part.. Jimmie Jimmie |
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