ADSL adaptor ok for ordinary RJ11 connection?

If I have a device with an RJ11 plug that I need to attach to my VirginMedia landline then, in general, can I use the RJ11 modem
socket on an ADSL Microfilter adaptor?
The device I currently want to attach is a recording adaptor but in future it may be some other device altogether. I'm concerned that:
(a) the modem socket on a typical ADSL Microfilter is usually wired differently than an RJ11 phone socket
(b) the ADSL Microfilter might be reducing the landline's voltage at the RJ11 socket and also limit the frequencies it passes thru to the point that that a device I attach could experience intermittent problems.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No - You must use the BT socket for any non-ADSL device. You have to plug in voice-band device into the BT socket of the ADSL filter. If you have an old modem or similar, with an RJ11 cable, then using a RJ11 to BT adaptor will work - providing the adaptor has the correct wiring - there are two "standards" for the adaptors...

Don't use the ADSL RJ11 socket for a phone-type device. You need to connect these to the BT socket. The ADSL RJ11 has the full ADSL plus phone signals and plugging your non-ADSL device into it will cause a problem for the ADSL signal. The BT socket is the one having the ADSL part filtered off.

The RJ11 ADSL socket is wired straight-through. There is no filtering in it's signal path. The Broadband modem should be the ONLY device connected to this RJ11 socket as the ADSL modem does it's own signal processing to remove the low frequencies of the phone-type signals.
--
John W
To mail me replace the obvious with co.uk twice
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"john" wrote: | > If I have a device with an RJ11 plug that I need to attach to my | > VirginMedia landline then, in general, can I use the RJ11 modem | > socket on an ADSL Microfilter adaptor? | | No - You must use the BT socket for any non-ADSL device. You have | to plug in voice-band device into the BT socket of the ADSL filter. | If you have an old modem or similar, with an RJ11 cable, then using | a RJ11 to BT adaptor will work - providing the adaptor has the | correct wiring - there are two "standards" for the adaptors... | > | > The device I currently want to attach is a recording adaptor but | > in future it may be some other device altogether. I'm concerned | > that: | > | > (a) the modem socket on a typical ADSL Microfilter is usually | > wired differently than an RJ11 phone socket | | Don't use the ADSL RJ11 socket for a phone-type device. You need to | connect these to the BT socket. The ADSL RJ11 has the full ADSL | plus phone signals and plugging your non-ADSL device into it will | cause a problem for the ADSL signal. The BT socket is the one | having the ADSL part filtered off. | > | > (b) the ADSL Microfilter might be reducing the landline's voltage | > at the RJ11 socket and also limit the frequencies it passes thru | > to the point that that a device I attach could experience | > intermittent problems. | | The RJ11 ADSL socket is wired straight-through. There is no | filtering in it's signal path. The Broadband modem should be the | ONLY device connected to this RJ11 socket as the ADSL modem does | it's own signal processing to remove the low frequencies of the | phone-type signals. |
Think you may have just jumped the gun a little there.
The OP stated that they are on a Virgin Media Landline, which probably means cable, which means no DSL signal on telephone.
The only problem that they may have then is if the RJ11 cable is not compatable pin to pin..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
:

So I did... - providing it is cable and not a LLU (C&W or the old Bulldog network)
--
John W
To mail me replace the obvious with co.uk twice
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat 28-Mar-2009 00:14, John Weston

Thanks for the info. No worries! My ADSL adapters were just spare in a drawer.
-------------
Better to get some new adaptors ...
(a) ...to connect an RJ11 plug to an BT-style wall socket. (b) ...to connect an RTJ9/4P4C plug to the BT wall socket.
These RJ plugs attach to a little device which permits recording of phone conversation. I presume I wouldn't want to use those adaptors advertised as a "crosswired". Is this correct?
--------------
I'm sure I once saw some good web pages about variations in how particular telephone wires are allocated to connectors. Maybe someone has a link to an article about the wiring of:
(1) telephone line cords (2) handset curly cords.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've had no problems using an old ADSL filter as a simple RJ11 to BT converter, since that part is straight through. I don't think I've had to use one on a Virgin cable connection, if that's what you have. I suppose the filter on the phone output could develop a fault but I've not seen one. If necessary, you can cut the wires to the filter inside the housing, since a cheap ADSL filter will usually be cheaper than the straight converter, see http://www.maplin.co.uk/Module.aspx?ModuleNo 494

I've not met the RTJ9 :-) A 4P4C, sometimes incorrectly called an RJ9 is a phone handset/headset connector and a handset shouldn't normally be connected directly to a BT socket. I've got one on a call recorder adapter, that goes between phone and headset but it is incompatible with direct connection to a phone line.

The two types of RJ11 are connects to the two inner connectors (2&3) or to the two outer (1&4). The more ususal one, for the first phone line, is the first. The line 1 converter connects the RJ11 pins 2&3 to 2&5 on the BT plug. The line 2 converter is 1&4 on the RJ11 to 2&5 on BT. The polarity doesn't normally matter, so cross-wiring them shouldn't stop it working.

Try here: http://telephonesuk.co.uk/wiring_info.htm (The "Grey" should be "Slate" :-) since G = Green)
--
John W
To mail me replace the obvious with co.uk twice
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun 29-Mar-2009 11:28, John Weston

Hello John W. For non-UK crossposted groups I should say I'm in the UK. Anyway, as an aside ....
I didn't know if the convention was to refer to 4P4C or to the modular plug used as a handset jack. The Wiki tells me that the RJ references (RJ9, RJ10, RJ22) for a 4P4C are technically incorrect but have gained widespread usage. I figured I wouldn't try to fight convention even if it is incorrect!

What you describe is also my situation. At the moment I use a Retell 156 in the curly lead and it's fine. Is that what you use?
I need another adapter for a different phone and decided to try some different ones: one by Commtel adapter and another by Uket.
http://cpc.farnell.com/commtel/41529740/telephone-recording - adaptor/dp/TE05106
http://www.uket.co.uk/digital-voice - recorders/accessories/telephone-recording-adapters/prod_130.html
The Uket supplier says he can attach it either to the handset curly (as it says on the web page) or to the line cord. The line cord is a bit surprising but I won't really know until I have tried. A friend of mine had an adapter which looked identical in appearance to the Uket one and it actually did work well when plugged into a wall socket with his own cord.
That's why I asked about variations in wiring line cords and curly handset cords (below). I figured maybe some combination of a telephone's non-standard wiring has permitted the adapter to work in the line cord. In fact, I very vaguely(???) recall there is poor standardisation for one or both of these:
(A) the pinout on the line cord's connector to the phone base.
(B) the pinout on either end of handset's curly lead.

Thanks for the link. It helped me find the following UK page which mentions non-standard line cord setup at the end.
http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephone/uk_telephone . html
As for the curly cord, a couple of articles in the Wiki don't agree about this.
http://en.wikipedia.org/wiki/Telephone_plug says: "(the handset cable) has a de facto standard of a 4P4C connector with straight through cable".
http://en.wikipedia.org/wiki/4P4C says: "When used for connecting handsets to the telephone base, the following pinout and wiring diagram is used. [See original page.] Because the microphone and speaker continue to function normally in the presence of reversed polarity, the cable itself can be wired as a simple crossover cable or as a straight through cable. Most telephone handset cords are manufactured as crossover cables.
That second page references this: www.gbpvr.com/pmwiki/pmwiki.php/Utility/DirecTVChannelControl where it says: "Each end of a handset cord is wired opposite the other".
Oh well. Perhaps a recording adapter doesn't care about this because it will join together the pair of contacts for the earpiece and the pair for the mic. I know this doesn't always work well because Retell make their expensive model 650 for those flaky occassions:
Retell 650 features http://www.retellrecorders.co.uk/recording/machine/650.htm
Retell 650 video http://www.retellrecorders.co.uk/support/productvideos/650video.htm
Retell 650 audio samples http://www.retellrecorders.co.uk/help/connectors.htm
Luckily my phone with the cheaper Retell 156 gives equal volume audio from both parties and this doesn't squelch either party.
Any comments from anyone on any of this are welcome.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, that's the one. I had a problem with it because the Tx and RX levels were incorrect for the French phone I was using. It's now in the cupboard... I'm now using the 145 which plugs directly into the phone socket using a supplied adaptor. (I plug mine into the back of a caller display unit, which has an RJ11 line socket, so don't use the adaptor) It doesn't have the playback to line facility, but it works better for me.

It's possible, since they are high impedance devices. However, the phone line is full duplex on one pair whereas the handset is Tx and Rx on two pairs, typically.

Ther is no standard for the phone lead in the UK, AFAIK. Most do seem to follow a similar layout, though. That's why they work with some phones and not with others.

The UK based manufacturers don't necessarily follow the USA practice as outlined in Wiki.
--
John W
To mail me replace the obvious with co.uk twice
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.