An excellent 'Pulse to Tone converter' is the 'Dial Gizmo' producted in Australia - it was specifically designed to use with Analogue Terminal Adapters for VoIP.
This is from their website
http://www.dialgizmo.com/
Dialgizmo is easy to install and use. Just connect it between your rotary phone and the phone line or VoIP box and you're ready to go.
•Easy setup, just plug in and use
•Supports all standard rotary phones
•Needs no batteries, no external power supply
•Converts 0-9 Pulse/Decadic dialing to DTMF tone dialing
•Allows you to dial * and #, a must have for dealing with phone banking systems
•Six speed dial locations plus last number redial feature
•Advanced microprocessor control for accurate dialing
•Suppresses dial pulses on the line to stop double dialing problems
•Not polarity sensitive. Dialgizmo will automatically adjust for incorrect phone and line wiring
•No modifications required to your old phone
•Configurable for non-standard dial layouts (Sweden, New Zealand)
•Does not interfere with ringer operation
•Supports a wide range of line voltages and currents
•Specially designed to tolerate the low line voltages on VoIP systems
It will also convert the New Zealand and Swedish dial pulses so that you can use telephones with the reverse order digits!
I've a couple of old New Zealand bakelite phones connected on CNet (
www.ckts.info/192/uk ) with New Zealand numbers.
Ian