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Old February 9th 12, 10:22 PM posted to sci.electronics.repair,rec.radio.amateur.antenna,sci.electronics.design
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First recorded activity by RadioBanter: Jul 2006
Posts: 398
Default Increasing Cable TV signal strength


Robert Baer wrote:

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.

Well, you could add an amplifier at the splitter where (nominally)
there is no power.
Use the coax center conductor for power; inline capacitors allow
signal to pass and feeding center via small choke allows DC but no signal.
Once upon a time there were little adapters that did this AC/DC thing...



A power inserter is used to put 9-28 volts DC on the coax, depending
on the amplifer you use.


--
You can't have a sense of humor, if you have no sense.
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Old February 9th 12, 08:09 PM posted to sci.electronics.repair,rec.radio.amateur.antenna,sci.electronics.design
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First recorded activity by RadioBanter: Jul 2006
Posts: 625
Default Increasing Cable TV signal strength

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
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Old February 9th 12, 11:35 PM posted to sci.electronics.repair,rec.radio.amateur.antenna,sci.electronics.design
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First recorded activity by RadioBanter: Jul 2011
Posts: 117
Default Increasing Cable TV signal strength


"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"


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Old February 10th 12, 02:01 PM posted to sci.electronics.repair,rec.radio.amateur.antenna,sci.electronics.design
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First recorded activity by RadioBanter: Jul 2006
Posts: 625
Default Increasing Cable TV signal strength

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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Old March 28th 12, 02:06 AM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Oct 2011
Posts: 72
Default Increasing Cable TV signal strength

Yes, just call the cable company, tell them you will change to satelite
because it doesn't work.

They will do it for nothing and very quickly.





"Jim Higgins" wrote in message
...
On Wed, 08 Feb 2012 13:00:12 -0600, 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?



Yes, ask the cable company to change the tap in the distribution
amplifier from (for example) -40dB to -34 dB. IOW, they can up the
signal level in the cable vs installing a lower loss cable. (You're
probably at the point where there isn't a significantly lower loss
cable available anyhow.)

Actually, first ask them to measure your signal strength at the
distribution point on your boat where their cable attaches and look
over their shoulder as they do that. They have specs and they need to
meet their specs. I had a ton of problems with Internet here until
doing that - finding they didn't meet their own specs - and when I
made them meet their own specs all was fine. They met their specs by
changing the tap.





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