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Old 19th Apr 2021, 11:43 am   #1
TheMeltonian
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Default GPO 300 and Virgin Media

Good morning all.
This morning my converted GPO 300 phone arrived, and I am having a couple of teething troubles with it which I wonder if you would be good enough to help me along with.

I plugged it in into the system, and hurrah I got a dial tone. However, when I try and dial a number, each time I dial an individual digit, it reverses back to the dial tone, as though it hasn't registered a string of numbers.

I realise that this may be down to needing a dialgizmo which I will shortly order, however, I also wonder if there could be something wrong with the speed of the rotary dial, and if so, is there a way to rectify this? Or could it be that until I have the dialgizmo it just isn't registering the pulses?

Secondly, and less importantly, as I believe I have rectified this when the phone was being rung, the bell wasn't sounding. I read a couple of similar posts and now have an RJ11 adapter with an integrated ring capacitor arriving in the next day or two, so hopefully, this problem should be averted.

In effect I suppose, are you able to tell me if the dialling out not working is an effect of lacking the dialgizmo, or is it a sign of something less easy to fix?
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Old 19th Apr 2021, 12:28 pm   #2
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Default Re: GPO 300 and Virgin Media

Can you try an electronic loop-disconnect telephone to confirm whether LD is accepted on your Virgin connection? This would obviate any tolerance issue with rotary dials.

If this works then yes: it's relatively easy to adjust the speed of your rotary dial, and you may not require that DialGizmo just yet!
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Old 19th Apr 2021, 12:44 pm   #3
TheMeltonian
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Default Re: GPO 300 and Virgin Media

Quote:
Originally Posted by russell_w_b View Post
Can you try an electronic loop-disconnect telephone to confirm whether LD is accepted on your Virgin connection? This would obviate any tolerance issue with rotary dials.

If this works then yes: it's relatively easy to adjust the speed of your rotary dial, and you may not require that DialGizmo just yet!
Thank you for the advice. I'm sadly not savvy with all the terms seen on the forum. What is an electronic loop disconnect phone?
In terms of phones that I have, I just have the GPO one and a standard modern tone dialling one, so I doubt I could try your experiment.
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Old 19th Apr 2021, 2:16 pm   #4
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Default Re: GPO 300 and Virgin Media

Quote:
Originally Posted by TheMeltonian View Post
In terms of phones that I have, I just have the GPO one and a standard modern tone dialling one, so I doubt I could try your experiment.
Loop Disconnect is another name for pulse-dialling. Your modern phone might have a switch somewhere that allows either DTMF (tone dialling) or LD (pulse-dialling): some phones do; some don't. Older ones tend to and the switch might be hidden away somewhere underneath.

Alternatively if you can't beg, steal or borrow a pulse-dialling instrument and you know someone who has a BT line, you could try your phone there. This saves investing time in getting the dial to work if the line won't accept it!
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Old 19th Apr 2021, 2:38 pm   #5
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Default Re: GPO 300 and Virgin Media

The advice Russell has given should differentiate between your 300-series telephone's dial being out of adjustment and your line not accepting LD pulses. If the latter, then a Dialgizmo or equivalent is the only way to go.

As far as the ringing problem is concerned, it may simply be that the socket into which your telephone is plugged doesn't have a connection (or in GPO terminology, perhaps that should be connexion) to the capacitor in the master socket. On the other hand the RJ11 with capacitor obviates the need for such connection anyway - and will be needed in any case if you use a Dialgizmo.

The only problem with using a local capacitor rather than one in the master socket is that you will get "bell tinkle" if you have another LD 'phone connected to the line and dialling out.
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Last edited by Dave Moll; 19th Apr 2021 at 2:42 pm. Reason: additional information
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Old 19th Apr 2021, 4:01 pm   #6
TheMeltonian
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Default Re: GPO 300 and Virgin Media

Thank you for those tips Russell, I shall take a look at the modern phone and see if it has a small switch somewhere.

I shall also have a hunt to see if I know anyone who has a BT line.

As for your point Dave, the bell tinkle shouldn't be an issue as I would only have one phone connected to the line.
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Old 19th Apr 2021, 6:05 pm   #7
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Default Re: GPO 300 and Virgin Media

Just a short thread update.

It seems that pulse dialling does work down here in Bournemouth on VM. I have managed to call out a couple of times as experimentation.
What seems to be the issue however is either the rotary movement needs some lubrication, as sometimes it snaps back too slowly. This I think is causing the issue for it not to register a dial (if you know where I can source relevant oil from, that would be grand) or that Whilst it does accept pulse dialling it is somewhat hit and miss.

I have also erred on the side of caution and order a dialgizmo, as just because it seems to work somewhat now, doesn't;t mean the dialgizmo won't come in handy in the future or make the operation of the phone smoother.
Thank you both Dave and Russell for your earlier advice!
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Old 19th Apr 2021, 7:30 pm   #8
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Default Re: GPO 300 and Virgin Media

Quote:
Originally Posted by TheMeltonian View Post
As for your point Dave, the bell tinkle shouldn't be an issue as I would only have one phone connected to the line.
I suspected that you would only have a single LD 'phone, but it's as well to be aware of the bell-tinkle situation.

Quote:
Originally Posted by TheMeltonian View Post
What seems to be the issue however is either the rotary movement needs some lubrication, as sometimes it snaps back too slowly.

...

I have also erred on the side of caution and order a dialgizmo, as just because it seems to work somewhat now, doesn't;t mean the dialgizmo won't come in handy in the future or make the operation of the phone smoother.
If your dial is too far from ten LD pulses per second (which it sounds as though it is) the Dialgizmo may not recognise the pulses either.

Others may be better able to give good advice on cleaning and lubricating a dial mechanism. If it is currently gummed up, this needs to be cleaned out before attempting lubrication.
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Old 19th Apr 2021, 7:31 pm   #9
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Default Re: GPO 300 and Virgin Media

Quote:
Originally Posted by TheMeltonian View Post
What is an electronic loop disconnect phone?
one that makes clickety-clickety-clickety noises as it dials out very, very slowly.

LD phones don't have * and # keys (or if they do, use them for redial and mute)

tone-dialling phones often beep-boop-buup-beep noises and dial very quickly, and usually have * and #
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Old 19th Apr 2021, 7:35 pm   #10
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Default Re: GPO 300 and Virgin Media

Quote:
Originally Posted by TheMeltonian View Post
'What seems to be the issue however is either the rotary movement needs some lubrication, as sometimes it snaps back too slowly. This I think is causing the issue for it not to register a dial (if you know where I can source relevant oil from, that would be grand)'
Just go easy on the oil there... A strategic drop on the end of a pin at relevant points will do: no more than that. There's an instruction here which you may or may not have seen. It might be worth removing your dial and cleaning it thoroughly first then re-lubricating it - it isn't a terribly onerous job. I expect you're meant to use Mobius oil or clock oil, or even light machine oil, but I use a drop of 3-in-one spray oil collected in a small dish. Don't use WD-40 and expect miracle results either.

I don't know about dial gizmos but they may be far more tolerant than the exchange and you can get away with more. Have fun!

https://www.britishtelephones.com/te...to%20b5125.htm
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Old 19th Apr 2021, 7:37 pm   #11
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Default Re: GPO 300 and Virgin Media

Quote:
Originally Posted by OscarFoxtrot View Post
LD phones don't have * and # keys (or if they do, use them for redial and mute)
And some LD/DTMF-switchable 'phones (e.g BT Vanguard) use the * key in LD mode to switch to DTMF for the remainder of the dialling.
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Last edited by Dave Moll; 19th Apr 2021 at 7:40 pm. Reason: quote added for clarity
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Old 24th Apr 2021, 8:36 pm   #12
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Default Re: GPO 300 and Virgin Media

If your dial is taking longer than say 1.5 seconds to return from dialling 0 then it probably needs cleaning.

I have just followed those instructions for a No. 12 dial on a 312F and it now works perfectly. The 300 series are very solidly built and easy to dismantle. Do clean the contacts carefully, I used a strip of printer paper soaked in contact cleaner (white spirit would do), placed between the contacts, then moved around whilst the contacts were closed.
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Old 24th Apr 2021, 9:16 pm   #13
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Default Re: GPO 300 and Virgin Media

op- one old test in the field for dial speed was to dial "0" let the dial return and say "one hundred one thousand and one". Of course as the dial should pulse at 10 pulses /second, it might be possible to time the dial ( stopwatch on phone) using the transmitter short contacts. ( one second)
To test the Virgin line for compatibility, you only need pick up handset /check for dial tone and tap the cradle . Dial tone should stop if line is LD.
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