strange signal spittler; bad reception on last tv in a row.

[micky]

Reception at a remote TV** has degraded and I thought maybe a splitter
connection had gotten bad, even though they are all indoors.

No electronics stores in town anymore. Home Depot has normal ones but
Google came up with
https://www.walmart.com/ip/2-Way-Coaxial-Splitter-2-GHz-90dB-1-DC-Passing/892650362

And my question is, 90db!!! I'd think it was a typo, but there's a
picture of it and it says it in big letters. This is loss, right?
Typical loss is 3.5db. With 90db loss, there's be almost nothing left.

Is this meant to fool suckers? Even if this were meant to fool suckers,
would anyone even make a splitter with 90db loss? (It also says 2.4GHz)

(It also says this, twice in a row: "With this splitter being capable of
frequencies up to 2GHz, there's no need to worry about signal loss or
degradation of runs up to 100 ft.")


Also, I've thought about replacing the first amplifier too. It seems to
be warmer than it used to be. IIRC it used to be just barely warm and
now it's warm to the touch. Similar looking amps claim 20db and 36db
and unspecified. Because of the splitter above, I'm suspeciaous that
36db might be phoney and actually no more than 20db. I can find the
links if you want them.

|--- 4 tvs in a row with an amplifier after the 2nd
DVDR-[**]-|
|--- 2 tvs in a row. Good reception at all 6 tv's except the
2nd one in this string.

**a splitter to 1 tv and an amp to all the others.

This had all been working fine for over 30 years. The problem tv
started giving problems a few years ago. Changing the tv didn't help.
(All but one are 14" CRT tvs.)


Back to splitters,
1) Any reason to buy a gold-plated splitter? Outdoor use?
2) Besides the extra $2 charge, is there any reason to NOT buy a
power-passing splitter if I'm not sending any power?

[Michael Terrell]

On Sunday, February 23, 2020 at 9:03:28 AM UTC-5, micky wrote:
> Reception at a remote TV** has degraded and I thought maybe a splitter
> connection had gotten bad, even though they are all indoors.
>
> No electronics stores in town anymore. Home Depot has normal ones but
> Google came up with
> https://www.walmart.com/ip/2-Way-Coaxial-Splitter-2-GHz-90dB-1-DC-Passing/892650362
>
> And my question is, 90db!!! I'd think it was a typo, but there's a
> picture of it and it says it in big letters. This is loss, right?
> Typical loss is 3.5db. With 90db loss, there's be almost nothing left.
>
> Is this meant to fool suckers? Even if this were meant to fool suckers,
> would anyone even make a splitter with 90db loss? (It also says 2.4GHz)

That is return loss or isolation between the output ports, not the insertion loss.

> (It also says this, twice in a row: "With this splitter being capable of
> frequencies up to 2GHz, there's no need to worry about signal loss or
> degradation of runs up to 100 ft.")

2GHZ rating is for Sat TV use between the antenna and the receivers.

> Also, I've thought about replacing the first amplifier too. It seems to
> be warmer than it used to be. IIRC it used to be just barely warm and
> now it's warm to the touch. Similar looking amps claim 20db and 36db

> and unspecified. Because of the splitter above, I'm suspicious that
> 36db might be phony and actually no more than 20db. I can find the

> links if you want them.

36 dB would overdrive your TVs unless the feed is really weak. You have a worst case loss of 10.5 dB in the splitters. The coaxial cable loss depends on the type, the length and the quality.

> |--- 4 tvs in a row with an amplifier after the 2nd
> DVDR-[**]-|
> |--- 2 tvs in a row. Good reception at all 6 tv's except the
> 2nd one in this string.

Swap the two outputs of the two way splitter and see if the same set sfill has problems, or if at moved to he other TV.

> **a splitter to 1 tv and an amp to all the others.
>
> This had all been working fine for over 30 years. The problem tv
> started giving problems a few years ago. Changing the tv didn't help.
> (All but one are 14" CRT tvs.)
>
>
> Back to splitters,
> 1) Any reason to buy a gold-plated splitter? Outdoor use?
> 2) Besides the extra $2 charge, is there any reason to NOT buy a
> power-passing splitter if I'm not sending any power?

Gold plating never tested better in the lab, and you don't need power passing for this application.

[Jeff Liebermann]

On Sun, 23 Feb 2020 09:03:23 -0500, micky
<NONONOa...@rushpost.com> wrote:

>Reception at a remote TV** has degraded and I thought maybe a splitter
>connection had gotten bad, even though they are all indoors.

Wild guess: Look for mouse or rat eaten coax cable.
Not so wild guess: Look for badly installed (loose) crimp type
F-connectors.

>No electronics stores in town anymore. Home Depot has normal ones but
>Google came up with
>https://www.walmart.com/ip/2-Way-Coaxial-Splitter-2-GHz-90dB-1-DC-Passing/892650362
>
>And my question is, 90db!!! I'd think it was a typo, but there's a
>picture of it and it says it in big letters. This is loss, right?
>Typical loss is 3.5db. With 90db loss, there's be almost nothing left.

90 dB might be the isolation between ports. The typical loss is 3.5dB
per port.

>Is this meant to fool suckers? Even if this were meant to fool suckers,
>would anyone even make a splitter with 90db loss? (It also says 2.4GHz)

It's easier to attribute such screwups to sloppiness than to
intentional fraud.

>(It also says this, twice in a row: "With this splitter being capable of
>frequencies up to 2GHz, there's no need to worry about signal loss or
>degradation of runs up to 100 ft.")

That's pure balony. There little difference in loss between different
flavors of 2 port splitters that would have any effect on coax cable
loss. Also, 100ft of RG-6/u has a loss of about 10dB.

>Also, I've thought about replacing the first amplifier too.

What amplfier?

>It seems to
>be warmer than it used to be. IIRC it used to be just barely warm and
>now it's warm to the touch. Similar looking amps claim 20db and 36db
>and unspecified. Because of the splitter above, I'm suspeciaous that
>36db might be phoney and actually no more than 20db. I can find the
>links if you want them.

Find the maker, model, and links if you want a sanity check on the
specs.

> |--- 4 tvs in a row with an amplifier after the 2nd
>DVDR-[**]-|
> |--- 2 tvs in a row. Good reception at all 6 tv's except the
>2nd one in this string.
>
>**a splitter to 1 tv and an amp to all the others.

Sorry, but I can't decode your drawing or where you put the amplifier.
Make a sketch and post it to one of the public image sites. Ignoring
the amp, splitting the power between 6 loads is a 7.8dB loss. Add
another 0.5dB loss per port, and you have a 8.3dB loss for each port.
That's quite a bit of loss and might cause problems if your TV has a
sensitivity problem. Hard to tell from here without signal levels and
measurements.

>This had all been working fine for over 30 years.

That's what they all say. "It was working great until something
happened" or something like that is the usual intro. Past performance
is not an indicator of future results. Incidentally, some coax cable
dielectric does tend to deteriorate after 30 years. If you're using
RG-59/u for your coax, think about replacing all of it with RG-6/u.

>The problem tv
>started giving problems a few years ago. Changing the tv didn't help.
>(All but one are 14" CRT tvs.)

Try temporarily moving one of the working TV's in place of the
non-working TV. If that works, the TV is sick. If it looks the same,
the cable, splitters, amp, coax, or connectors might be the problem.
Also, unterminated ports can cause weird problems. If you have any,
plug them with 75 ohm terminations.

Also, try moving the problem TV closer to the "DVDR" (whatever that
might be), removing the cables and splitter from the equation. If
that works, look for something broken between the DVDR and where the
TV was originally located.

>Back to splitters,
>1) Any reason to buy a gold-plated splitter?

No. The difference in surface conductivity beween the various metals
and gold will not produce any visible (or easily measurable)
difference.

>Outdoor use?

Gold might help prevent corrosion, if it were thick and pure enough.
Instead, look for a splitter that is totally sealed waterproof. Shove
a paper clip into the center of the 3 F-connectors. If it stops, the
hole is plugged and water won't get in. If the paper clip goes in
past the connector, water will be a problem. Also, put some effort
into making your installation look semi-professional and use drip
loops for anything you don't want to get soaked in water.
<https://www.google.com/search?q=splitter+drip+loop&tbm=isch>

>2) Besides the extra $2 charge, is there any reason to NOT buy a
>power-passing splitter if I'm not sending any power?

Why do you need a splitter that will pass DC? Are you powering any
amplifiers through the splitter? If so, you'll need the DC pass. If
not, you can use a DC pass splitter, but the DC pass doesn't do
anything beneficial to the RF.

Notice that it's really easy to buy crap splitters:
<http://www.learnbydestroying.com/jeffl/crud/CATV-splitters.jpg>
<http://www.learnbydestroying.com/jeffl/crud/CATV-splitter.png>


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[micky]

In sci.electronics.repair, on Sun, 23 Feb 2020 07:49:17 -0700, KenW

<ken...@invalid.net> wrote:

>On Sun, 23 Feb 2020 09:03:23 -0500, micky
><NONONOa...@rushpost.com> wrote:
>
>>

>>Reception at a remote TV** has degraded and I thought maybe a splitter
>>connection had gotten bad, even though they are all indoors.
>>
>>No electronics stores in town anymore. Home Depot has normal ones but
>>Google came up with
>>https://www.walmart.com/ip/2-Way-Coaxial-Splitter-2-GHz-90dB-1-DC-Passing/892650362
>>
>>And my question is, 90db!!! I'd think it was a typo, but there's a
>>picture of it and it says it in big letters. This is loss, right?
>>Typical loss is 3.5db. With 90db loss, there's be almost nothing left.
>>
>>Is this meant to fool suckers? Even if this were meant to fool suckers,
>>would anyone even make a splitter with 90db loss? (It also

......
>
>Probably 90db isolation between output ports
>
>
>KenW

That accounts for it. Thanks.

[Adrian Caspersz]

On 23/02/2020 17:53, Jeff Liebermann wrote:

>> Is this meant to fool suckers? Even if this were meant to fool suckers,
>> would anyone even make a splitter with 90db loss? (It also says 2.4GHz)
>
> It's easier to attribute such screwups to sloppiness than to
> intentional fraud.
>

They put anything on the packaging if it makes a sale,

I have a 50 ohm keyboard

https://app.box.com/s/n3v98f2cl6qqm0rk1d22gv7o9i5blpge

--
Adrian C

[Ian Jackson]

In message <b5946flifqd47cfb5...@4ax.com>, micky
<NONONOa...@rushpost.com> writes

90dB is highly optimistic. 40 dB would be more typical (but still
adequate), and maybe a bit less at 2GHz.

If they do mean 90dB, it's probably the screening factor (a measure of
signal leakage and ingress). 90dB would be good.
--
Ian

[Clifford Heath]

Could be 90dB/Hz?

CH

[Tony]

Just found this one with google. It has 90dB RFI shielding:

https://www.computercablestore.com/coaxial-splitter-catv-f-type-3-way-1ghz-90db#full-description

Now it makes sense

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[Charles Lucas]

On Sunday, February 23, 2020 at 8:03:28 AM UTC-6, micky wrote:
> Reception at a remote TV** has degraded and I thought maybe a splitter
> connection had gotten bad, even though they are all indoors.
>
> No electronics stores in town anymore. Home Depot has normal ones but
> Google came up with
> https://www.walmart.com/ip/2-Way-Coaxial-Splitter-2-GHz-90dB-1-DC-Passing/892650362
>
> And my question is, 90db!!! I'd think it was a typo, but there's a
> picture of it and it says it in big letters. This is loss, right?
> Typical loss is 3.5db. With 90db loss, there's be almost nothing left.
>
> Is this meant to fool suckers? Even if this were meant to fool suckers,
> would anyone even make a splitter with 90db loss? (It also says 2.4GHz)

The 2.4 GHz is for wireless signals for the internet (like a cable modem
and router) and also work for TV's- just that they run on different bandwidths.
TV's run at about 1 GHz maximum. The decibel level for signal amplification
is usually between 6-9 dB (decibels). The 90 dB rating is for audio output on
devices with digital audio output (up to 90 dB on playback).

>
> (It also says this, twice in a row: "With this splitter being capable of
> frequencies up to 2GHz, there's no need to worry about signal loss or
> degradation of runs up to 100 ft.")
>
>

True for wired signals. Wireless is an entirely different matter. You can
have architectural issues that interfere with the signals getting from one
point to another (example is someone only getting signals downstairs
and not upstairs). This goes into a different line of discussion.

> Also, I've thought about replacing the first amplifier too. It seems to
> be warmer than it used to be. IIRC it used to be just barely warm and
> now it's warm to the touch. Similar looking amps claim 20db and 36db
> and unspecified. Because of the splitter above, I'm suspeciaous that
> 36db might be phoney and actually no more than 20db. I can find the
> links if you want them.
>
> |--- 4 tvs in a row with an amplifier after the 2nd
> DVDR-[**]-|
> |--- 2 tvs in a row. Good reception at all 6 tv's except the
> 2nd one in this string.
>
> **a splitter to 1 tv and an amp to all the others.
>
> This had all been working fine for over 30 years. The problem tv
> started giving problems a few years ago. Changing the tv didn't help.
> (All but one are 14" CRT tvs.)
>
>
> Back to splitters,
> 1) Any reason to buy a gold-plated splitter? Outdoor use?

The gold plating offers lower resistance, but that is all. Other than
that, there is not much difference there.

> 2) Besides the extra $2 charge, is there any reason to NOT buy a
> power-passing splitter if I'm not sending any power?

The reason for bypass on the power is if you are not driving a tuner
on the outboard side of one of the legs of a splitter (i.e. you are running
a cable modem and then router on one of the legs of the splitter).

I would also suggest you look at the placement and the configuration of the
wiring. amps, splitter/(s), devices, the routing of the wiring, etc.., where you
placed the splitter (and signal amps), check gain controls and AGC (where
applicable). Make sure all wiring is good, the connections are good, firm, and
securely connected. Make sure the proper signal path is followed.