POTS Filter Question

portcullis

portcullis

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This is going to sound like a real noob question, but I'm asking it anyway.

I've got a whole bunch of kit here that I'm prepping for an install tomorrow and the POTS filters are slightly strange.

They have Telkom written on them and are brand new in their sealed bags.

Thing is, they only have one RJ-11 socket with the word "PHONE" embossed on the plastic next to it.

Am I right in thinking that I'm supposed to plug the routers directly into the one socket on the Telkom wall box and the POTS filter and phone / PABX into the other one?

If this is the case, what filtering is being done by the POTS filter? Just voice?

Is this going to have a negative effect on the client's ADSL connection speed?
 
The POTS filter is supposed to look like this: <female RJ11 socket> [box] <male RJ11 socket>.
They are used as follows: Plug POTS filters into ALL your available RJ11 sockets except for the one where the router should be plugged into.
In short, it filters out the the non-voice wavelength so that you can have a clear line (not going to go into detail).
This is actually pretty crucial to having a working ADSL connection. Without POTS filters you could have intermittent ADSL issues.
 
In the past eight years, I've installed hundreds of POTS filters. Each one I've ever seen has had two RJ-11 sockets. One marked ADSL (or something similar) and one marked Phone (or something similar).

These one have no "ADSL".
 
They're fine, don't worry. The ADSL part of the dual port filters are simply pass-through, it doesn't actually filter anything.
 
portcullis said:
In the past eight years, I've installed hundreds of POTS filters. Each one I've ever seen has had two RJ-11 sockets. One marked ADSL (or something similar) and one marked Phone (or something similar).

These one have no "ADSL".
Click to expand...

Oh you mean those types..... yeah, see Tacet's reply.
 
Thanks guys.

You know I'm going to have to open one of the next batch of "2 socket" POTS filters we get to find out what's happening on the ADSL side.
 
The 1 port ones are fine if they say "phone" on the RJ11 port. Just don't plug in an ADSL router in it, because then it would filter out all of the ADSL's signal. The "phone" POTS filters are low pass filters, which essentially filters out everything above 20kHz. The ADSL modem operates roughly at 25kHz - 3MHz, but they would also cause some slight noise in the lower frequencies. Without a filter for the ADSL modem too, you'll have some noise on your normal voice/telephone line.
 
Cool. I also noticed this with my new Telkom router. Thought it strange getting two pots filters where one had one Female jack and the other two female jacks.
 
Pada said:
The ADSL modem operates roughly at 25kHz - 3MHz, but they would also cause some slight noise in the lower frequencies. Without a filter for the ADSL modem too, you'll have some noise on your normal voice/telephone line.
Click to expand...

That should be "could" and "might" rather than "would" and "will". Many DSL modems have clean signals which doesn't cause any interference on the POTS line. I don't use a POTS filter at home, simply as it is not necessary for our phone/modem combination.
 
The POTS filters are simply lowpass filters that filter out high-frequency components of the signal (used by ADSL) for your voice connection.
 
Sounds like the filter you have is for the phone line only...so you need to split the line before it goes to the filter. Most pots filters are like a combo...it has the splitter and filter in one :)
 
Hi,

This raises a question in my mind...

I have a check with two RJ11 female ports.

Would it be better to
a) plug the POTS filter into one and then the ADSL AND Telephone line into the POTs filter or;
b) plug the ADSL directly into 1 RJ11 socket and the POTs filter into the other (and connect just the telephone line to the filter)

Thanks
 
ADSL into the POTS filter won't work - you'll filter out your ADSL... Unless you're speaking about a filter that has two RJ11 jacks, with one marked "Phone" and the other marked "ADSL"? But never connect a filter with only one RJ11 port to your ADSL.
 
All this gesukkel has got me thinking back to June 2002 when I bought my first house in England.

I bought one of these from Solwise, fitted it and that was the end of it.

Back then the ADSL ran at something like 512Kb and cost me something stupid like £130 a month with 5 public IPs. Today it costs me £17 a month for 10Mb with 5 public IPs. That ADSL is so good that I can run a mail server and a VPN router on it.
 
I had Telewest cable (later NTL, now Virgin) for all of one month and decided that my Zen ADSL is so much better...
 
Hi,

I am referring to the filter with 2 RJ11 sockets...

Cheers
 
Aharon said:
Hi,

I am referring to the filter with 2 RJ11 sockets...

Cheers
Click to expand...


So you have two devices:
1) A splitter, that doesn't do any filtering,with two RJ11 jacks.
2) A splitter, with one ADSL RJ11 jack and one telephone RJ11 jack.
?
 
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