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All systems has + & - sides should I chose old or new system for my phones?

Started by dsk, October 05, 2020, 01:16:25 PM

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I have this one:
And I have IP telephony.

Please do not just answer the old one because it is not that simple.
I have not too good trunk, reasonable for calling out, but just a single ringer on incomming calls, and the I have to dial the trunk to answer. 
I  is not possible to transfer a call.The power supply to the phones i2 only 24V on a single un-balanced supply so if one phone draw a lot of current the other will not get enough.

On the other hand, the IP system will fail on a power out. It will sometimes fail and act as one way sound (never figured out why, but that happens on "professional" systems too.)
The big pre's is incoming calls may ring lots of phones, I may transfer calls. I may configure routing and short numbers.

I will absolutely say that both 3CX works well and is free, and Callcentric has good systems, almost free, the combination is really nice. But I may still use much of that on my trunk line. (not transfere)



I'll more and more go for the old step by step exchange. If I use Norwegian, or north American phones it will work pretty well, but German phones from before wwii will demand much more power they were designed for their systems with higher voltage, and as much as 60 mA line current.  May be I may do what we always say we should not. I may put a battery in series with the phone.  Another solution is to solder in a capacitor in the anti sidetone part of the circuit. 



I'll give it a try, its always possible to change to something else.

Should not be to afraid to try :-)



Now it is working pretty stable, no need or service at all the last year. Last was new (old) batteries a year ago. I have learned that the powersupply should not give more then 12.6V pr 12V battery, that keeps it almost fully charged, but not drying it out.

The most difficult was to make trunks that could understand pulses from the PAX and could send pulses to the PAX.  Now it works with phones that has no restance in series with the dial when dialing. 

I'm happy with that. :)

Kellogg Kitt

I am glad you got it working well!  I used to dream of having my own step-by-step switch with all my phones connected to it, but I am afraid I would not have the technical expertise to keep it running.


I did not expect to get to get it working, and my knowledge about this is not high ???
By luck, or ? It is working, actually as the only one of its kind that I know. Even the Museum of sci.
does not have been able to keep their alive.
The only problem that had to be solved was to replace 2 capacitors.

Then I had to learn a lot, .... Batteries, power-supply, fuse wires... And to make trunks.  Had been a long process, but fun.