[effdee]

> This old device should support pulse tone dialing, but it did not work with mine. Might be the custom firmware, might be AVM dropping support in later versions, I'm not sure.

The timings of the phone's rotaty dial might be off. Allegedly FritzBoxes are rather conservative when it comes to these timings.

I just had the same problem with an old Tischfernsprecher W 48 which neither worked on a FritzBox 7560 nor a 7590. Adding a pulse to tone converter solved the problem.

Btw, in case pulse dialing works with a FritzBox one can dial # via hook flash. This allows to dial the internal numbers [0].

[0] (in German) https://www.wasser.de/telefon-alt/forum/index.pl?job=thema&t...

[082349872349872]

In the US, whatever was interpreting the pulse dialling was very lenient; some people tried to create "incoming-only" phones by locking a metal plate over the rotary dial, but other people would make outgoing call pulses manually via hook flash.

[jgrahamc]

From personal experience: in the UK also.

[b112]

Same in Canada. Did this as a kid all the time, just because.