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 Big fan of decadic dialling
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 Return to top of page · Post #: 1 · Written at 2:14:36 AM on 5 March 2017.
Erikpill's Gravatar
 Location: Wollstonecraft, NSW
 Member since 2 March 2017
 Member #: 2074
 Postcount: 2

Hi all, I'm in Wollstonecraft, Sydney on the St. Leonard's exchange. I've been researching what options are open to me to continue to use my decadic phones once I am forced to move over to the NBN, and came across this site. I'm impressed! A lot of very interesting content here, so I decided to join up.

I have some questions about the above and will post them in the right forum; I've searched a bit and see there was some discussion about the topic but nothing in the last couple of years.

So see you there!

All the best, Erik.


 
 Return to top of page · Post #: 2 · Written at 11:52:34 AM on 5 March 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5505

Welcome to the forums Erik. How we'll use our old Bakelite phones (and more recently made phones with rotary dials) does at times become a conversation and is probably overdue for another with the NBN and VOIP becoming a fact of life for many people.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 3 · Written at 1:49:22 PM on 7 March 2017.
Robbbert's avatar
 Location: Sydney, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 1074

I have a whole box full of pulse (decadic) phones, made by AWA, with plastic cases of various colours. Some are pushbutton but still send pulses. I expect I'll have to throw them out when NBN becomes a reality.


 
 Return to top of page · Post #: 4 · Written at 8:48:29 PM on 7 March 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

Don't throw them out before listing them on here.


 
 Return to top of page · Post #: 5 · Written at 11:03:24 PM on 7 March 2017.
Robbbert's avatar
 Location: Sydney, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 1074

You're right, I should do that. Most of the phones are still in the original boxes. I also have a 2 line-in, 6-extension manual phone exchange to get rid of as well. It worked last time I tried it (about 30 years ago), and comes with a schematic and a brochure.


 
 Return to top of page · Post #: 6 · Written at 11:06:34 PM on 7 March 2017.
Vintage Pete's avatar
 Location: Cromer, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 1050

Welcome ,
I have a old Bakelite wall phone that came from an old Pub in SA.

While I was living at Thornleigh sydney this phone was connected and worked fine. It was the daily driver in my house, But 8 months ago I moved house to Cromer down on the northen beaches and I plugged it in and nothing . Wont work here ,neither will my Homicide phones ericsson.
So I'm suck using a hideous modern phone that does not match all my 50s stuff in the house. I have a good friend who use to work as a techo for PMG and then he worked at Telstra until the out the door package was offered to him .I might ask him if there is anything that can be done to able me to use my old phones.

Gosh might have to move again ))))))))))))))),,,,pete


 
 Return to top of page · Post #: 7 · Written at 11:52:05 PM on 7 March 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

Wont work here

If you have standard old copper phone line, then it ought to still support decadic dialling. However, if you have HFC cable and your phone service comes from that then no decadic support.

As discussed elsewhere in this section, there is a (non-approved) decadic to tone converter that you can use.


 
 Return to top of page · Post #: 8 · Written at 9:06:25 AM on 8 March 2017.
Vintage Pete's avatar
 Location: Cromer, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 1050

. GTC
Hi,, G
That makes sense because the house I lived in at Thornleigh was a very old house ,but the new house I moved into into is not very old. I have always lived in old houses with the exception of this one . I find in hard to adjust too.
All the best pete


 
 Return to top of page · Post #: 9 · Written at 5:33:12 PM on 15 March 2017.
Relayautomatic's avatar
 Location: Canberra, ACT
 Member since 24 April 2012
 Member #: 1136
 Postcount: 105

Welcome Erikpill. Don't worry it is fairly easy to get the old decadic (rotary) dial phones working on the modern system if you have a copper pair to the exchange. It should also be straight forward to get the same phones working on the NBN assuming you have fibre-to-the-premises. The conversion from decadic to DTMF to call out is easy but getting the phone to ring on incoming calls may by the real problem. There are also adaptors to connect decadic phones to a 3/4G mobile phone if it has Bluetooth. I did cover this on the Telephone forum some time ago. However be aware that anything you do will be contrary to the ACMA rules. (See the ACMA site for more information.)

The first issue is to identify what phone you have as the old bakelite phones (typically a 332AT, 300AT or a 400AT) have a different circuit to the later plastic 8000 series (801AT or 802AT). The Ericofone is different again. These phones may also have different plug and socket combinations. They can all be made to work once you understand the circuit.

The circuit in each phone has three sections; one section is a capacitor in series with the bell motor so that the phone rings on incoming calls; another section handles speech and is made up of a induction coil (special audio transformer) plus a resistor/capacitor balance/anti-sidetone network which matches the carbon microphone and electro-magnetic receiver to the phone line; while the third section is the dial and a spark-quench/pulse shaper to send a series of pulses to the exchange depending on the digit dialled. (1 = one pulse, 2 = two pulses, . . . , 0 = ten pulses.). The hook switch in the phone and contacts in the dial switch in the appropriate section of the circuit. When the handset is on the cradle only the capacitor and bell motor are connected to the line. There is 48-50V DC on the line but this is blocked by the capacitor. If the ringing signal 75-90V AC at 20-25Hz is imposed on the line from the exchange then the ring current passes through the capacitor and the bell motor operates ringing the bells. If the handset is lifted then there is a DC path through the speech network and a relay at the exchange operates stopping the ring signal and allowing the phone to transmit and receive audio signals. When you hang up the DC circuit is broken and the relay at the exchange drops out clearing the call. If you are making a call then as the handset is lifted, a DC path through the speech network is connected and a relay at the exchange operates. When the dial is turned a pair of contacts close to short out the speech circuit to prevent loud clicks being heard in the earpiece. As the dial returns a cam wheel operates another set of normally-closed contacts open for a few milliseconds so that a high speed relay in the exchange drops out activating a counter circuit. Depending of how far the dial is turned before being released then more of the cam is exposed so that normally-closed contacts open as many times as the digit dialled. When the dial has returned to the start point then the shorting (off-normal) contacts open so that the speech circuit works again.

All exchanges still use the 48-50V DC and 75-90V AC combination so an old phone should still be able to send/receive speech and ring on incoming calls. However only some Telstra exchanges still accept decadic (Pulse) dialing. Optus and other carriers only work with DTMF dialling. There are relatively cheap adaptors that convert decadic dial pulses to the equivalent DTMF signal. Some of these adaptors are fitted inside the phone while there is another Australian made adaptor that goes between the phone and the line socket on the wall. (I have tried both types and they worked well.)

The possible catch is how to ring the bell on incoming calls. Some old phones were modified to work with extension bells and had a wire link in the wall socket to complete the series circuit. If the phone is plugged into a socket without the link then the phone will not ring but can transmit and receive speech. The simple fix is to add a wire link inside the phone (but just where to put the link depends on the model of the phone).

The other reason that a phone may not ring is the interface that is in the house (most likely the NBN module) may not put out enough power (AC voltage too low or the frequency may be too high) to operate an inductive bell motor. These units assume a modern phone with an electronic ringer that will work on 35-50V AC at 50Hz. There is a fix for this but it is more difficult to implement.

Depending on what the Moderator will allow to be posted I can give more details and specify brands.

Andrew


 
 Return to top of page · Post #: 10 · Written at 6:19:30 PM on 15 March 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5505

Depending on what the Moderator will allow to be posted I can give more details and specify brands.

Post to your heart's content. Smile


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 11 · Written at 7:32:32 AM on 16 March 2017.
Wa2ise's avatar
 Location: Oradell, US
 Member since 2 April 2010
 Member #: 643
 Postcount: 725

QUOTE: decadic phones

In the USA we call them "rotary dial" phones, and I have a couple still in service here. We still have "Plain Ordinary Telephone Service" (POTS) here.

Heard of some young kids being baffled by a rotary phone, not knowing how to make a call with it...


 
 Return to top of page · Post #: 12 · Written at 4:42:35 PM on 16 March 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5505

Heard of some young kids being baffled by a rotary phone, not knowing how to make a call with it...

Much the same story here. The same perplexed people ask about the lack of the Internet, mobile phones and ATMs, to which the best reply is, "we planned our day better".


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
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