Dialgizmo no dial tone

[PaulR]

In view of the imminent change to VIOP i decided to buy a Dialgizmo to anable me to continue to use my variety of old phones. I have had a Rotatone on one of them for years and it has worked very well but the rest are unmodified.

I bought a UK plug to RJ11 adapter and the reverse as the Dialgizmo only uses RJ11. Unfortunately there is no dial tone with it in circuit. I tried connecting the adapters directly together, removing the Dialgizmo and the dial tone returned. I have read another thread about this and it mentions a crossover rj11 to bt adapter. As far as I know the one I bought was "straight" but the phone seems to work with it in circuit. Can anyone advise me about this?

Also, the Dialgizmo uses only two wires. I read in another thread about s two to three wire adapter which introduces a capacitor and uses the third wire for this. I assume I will also need one of these to make the phones after the Dialgizmo to work?

Thanks

[Dave Moll]

If both adaptors are the wrong type, the errors will cancel out when connected without the Dialgizmo.

[PaulR]

The one which plugs into the wall is one plastic moulding and a fly lead from the dialgizmo plugs into that. The other is a short lead with an RJ11 plug on one end and a BT socket on the other.

[Dave Moll]

The problem is that these exist both in "straight-through" configuration where each position in the RJ11 is connected to the same position in the BT431, and "crossover" where the 2/5 pair of each is connected to the 3/4 pair of the other. In each case, if both are of the same configuration, the BT sockets will effectively be straight-through, whereas the RJ11s need the crossover configuration.

[Graham G3ZVT]

If you have a spare RJ11-RJ11 cable and an ADSL microfilter, you can use the latter to convert one end of the cable to BT431, plus it will connect the centre pair (3&4) of the RG11 to the outer pair (2&5) of the BT plug, which is what you want.

[PaulR]

Thanks both. I hadn't thought about the pin connections but, of course, if they are "straight through" the opposite pins will be connected.

So, is the best way to use an ADSL microfilter for the line side as Graham suggests and a reversed BT socket to RJ11 for the phone end? Would that solution make the phones ring? If I didn't use the ADSL filter method would I also need a reversed connection for the line end?

[Dave Moll]

Yes, 2/5 of the BT plug need to go to 3/4 of the RJ11 socket and 3/4 of the RJ11 plug need to go to 2/5 of the BT socket.

If you want third-wire ringing on the output from the Dialgizmo, you will need an ADSL filter on the output (telephone set side), as the Dialgizmo uses two-wire connections (at least mine does).

[PaulR]

Thanks Dave. Just to get this right. If I use an ADSL filter will I then need a straight through adapter as the filter reverses the connection itself? My Dialgizmo also uses two wires.

[Dave Moll]

If using ADSL filter on output, its input and output are both BT, so it doesn't perform any crossover.

[PaulR]

Right, thank you

[PaulR]

I can find loads of RJ11 socket to BT plug crossover adapters but I am struggling with a BT socket to RJ11 plug one. Can anyone point one out for me please?

[Graham G3ZVT]

An RJ11-RJ11 lead and a microfilter will solve that problem too!

[Graham G3ZVT]

If you'd rather not improvise, here's the real deal
https://soho66.co.uk/7369/all/1/RJ11...acitor%29.aspx
Note that this one has an internal capacitor which may be needed to make vintage phones ring, most don't have this.

[PaulR]

Thanks Graham

[PaulR]

I bought an adapter with a ring capacitor and have just received and fitted a crossover adapter for the other end.

All now seems to be working. The pulse phones dial out with a tone (as long as you don't dial too fast) and the phones all ring. I haven't tried the * and # yet,

Thanks for the help, all.

[PaulR]

Another problem has now arisen. I recently bought a 200 series phone in excellent condition. It dials out fine without the dialgizmo. With it, it makes tones but these are clearly wrong as I get the "the number dialled has not been recognised" message. My other similar phone works with it. I have tried slowing it down with my finger but it doesn't help. If I dial by tapping the T bar the receiver sits on, I can dial out correctly.

There are three contacts on the dial and I have cleaned them all using increasingly aggressive cleaners starting with switch cleaner on card, followed by Brasso on card and finally very fine emery paper. The resistance across the make and break contacts when connected is around 0.5 ohms.

Can anyone suggest a solution?

Thank you

[PaulR]

Another update on this. The dial is a type 10 which is different from those on other phones I have. There are two contacts whose purpose seems to be to quieten the impulses heard when dialling. These seem to be adding an extra impulse which is picked up by the dialgizmo. If I turn the dial a little so as not to reach "1" then I hear a tone when it returns to rest.

If I adjust these contacts so that they do not break contact when I dial then I can hear the impulses loudly in the ear piece but the phone dials correctly.

As said earlier the phone works correctly when omitting the dialgizmo.

Is there anything I can do about this or is it because of the type of dial employed?

Edit - it is adding another pulse - if I "tap" "1" then dial 4 , 6 then tap "1" again I connect to the 1571 number