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Old 17th Apr 2024, 2:18 pm   #1
SimonFrench
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Default Help needed with GPO 746F

Hi everyone,

I'm in Portugal and have a GPO746F converted to BT plug (no Rotatone installed) and which I'd really love to be able to use with my Fibre router - this has 2x FXS sockets.

Simply plugging it in using a BT to RJ11 converter allows me to dial out successfully and I can also receive incoming calls perfectly but the phone doesn't ring

Having read that a ring capacitor is necessary and, if missing, an ADSL microfilter would suffice I added one between the RJ11 plug and FXS socket but without any joy.

I believe that what I'm trying to achieve should be possible and I've attached a photo of the current wiring.

Any help you can give me in solving this problem would be really appreciated

Thank you
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Old 17th Apr 2024, 3:06 pm   #2
Nickthedentist
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Default Re: Help needed with GPO 746F

Hello and welcome, Simon.

Here's a diagram of how they were originally wired, before plugs and sockets, to the two wires from the exchange ("A" and "B").

To replicate, and make use of the phone's built-in ringing capacitor (C1), wire it like this:

-Leave the handset wired as it is.
-Make sure the bell is connected between T4 and T16.
-Link T4-T5-T6-T7.
-Link T8-T9.
-Link T16-T17-T18-T19.
-Connect your router's telephone output to T8/9 and T16/17/18/19 (e.g. red to T8 and white to T17, as you have it wired currently).
-"Park" unused line cord wires (green and blue) on any of the unconnected terminals (T11-T15).
-Don't worry about the 3K3 resistor at this stage, you probably don't need it.

Let us know how this goes

Nick,
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Old 18th Apr 2024, 9:53 am   #3
SimonFrench
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Default Re: Help needed with GPO 746F

Thank you so much Nickthedentist for your help.

I'll pop out on Saturday and pick up some bell wire and spade terminals so that the links are a neat job.

Hopefully I'll be able to report back with some good news

Simon
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Old 18th Apr 2024, 3:51 pm   #4
Nickthedentist
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Default Re: Help needed with GPO 746F

Pleasure.

Personally, I would try a quick lash-up with some offcuts of single core wire with the insulation removed. It can be done neatly without using spade terminals.
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Old 19th Apr 2024, 3:45 pm   #5
Graham G3ZVT
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Default Re: Help needed with GPO 746F

Hi Simon. What is the make and model of the router, it's always useful to know which ones allow LD dialling on their FSX port(s), as it's quire rare.

Regarding the ADSL micro-filter, I imagine it's only the UK ones that have an internal ring capacitor due to our unique sockets and wiring.
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Old 21st Apr 2024, 9:58 am   #6
SimonFrench
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Default Re: Help needed with GPO 746F

Thank you everyone, simple things such as thin bellwire can be difficult to source down here on the Algarve so I've had to resort to Amazon

It'll be here later this week, I can then make the modifictation to the wiring & report back

In the meantime I can answer the question from Graham G3ZVT about the router which works fine with pulse dialing - it's an Altice Labs GR241AG supplied by my telco.

The link to the manual (in Portuguese) is

https://conteudos.meo.pt/meo/Documen...dor-V4.0-3.PDF
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Old 26th Apr 2024, 2:07 pm   #7
SimonFrench
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Default Re: Help needed with GPO 746F

Thank you NicktheDentist, I wired it up as per your instructions and it now works perfectly with the Altice Labs GR241AG (Meo Fibre Gateway).

In case it might help others in the future I have attached a couple of photos of the final wiring (modifications in yellow)
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Old 26th Apr 2024, 8:07 pm   #8
Nickthedentist
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Default Re: Help needed with GPO 746F

Well done and thanks for taking the time to let us know.
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