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Old 19th May 2020, 1:37 pm   #2
Pellseinydd
Heptode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
Default Re: VOIP Phone line and my Bakelite telephones

It is quite possible to use old Bakelite telephones with VoIP - all you need is an Analogue Terminal Adapter that accepts pulse dialling telephones. The Grandstream HT502/504, HT701,702,704 and the current range of HT8XX work with pulse dialling as do the harder to find GXW4004/4008 ones. However they are designed for use with American pulse dialling telephone which have a 40% make/ 60% break ratio for each pulse working at a speed of 10 impulses per second. The UK ratio is 33.3%make/66.6% break but still with 10 IPS. Sometimes if the pulse phone is not perfectly adjusted, it may be nearer the US spec. It is easy to get around it by 'tweaking' the dial by moving the pulsing contacts very slightly closer together to achieve the 40% make ratio. I've got numerous GPO Bakelite and 700 types working with Grandstream ATAs on both public phone lines and on CNet, our own VoIP phone network that we've built up over the last 15 years using the old GPO dialling codes of many years ago - still old GPO exchanges connected to it. Must be a good network as even BT now have lines off it!
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