Classic Rotary Phones Forum

Telephone Switching => Strowger (Step by Step) Switching => Topic started by: dsk on September 05, 2013, 08:45:46 AM

Title: Elektrisk Bureau PAX SXS with drums
Post by: dsk on September 05, 2013, 08:45:46 AM
The PAX was saved from a container, and yes it works.
Much about this in another thread:http://www.classicrotaryphones.com/forum/index.php?topic=4185.45 (http://www.classicrotaryphones.com/forum/index.php?topic=4185.45)

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on September 05, 2013, 08:49:51 AM
Just a little more.
Diagram, and how I made one line to be an outbound trunk line.
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on August 14, 2014, 01:10:57 PM
Not easy to keep it running as I want, the trunk has had trouble with releasing the line. I replaced the zener and diode in series with the dial repeat (and release) relay with a resistor.

Now I have to try it out.

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: poplar1 on August 14, 2014, 02:42:03 PM
Does this PAX require ground start trunks or loop start trunks?
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on August 14, 2014, 03:27:23 PM
It is loop start.
Ground start has not been used here as far as I know.
This PAX does not have a trunk line at all.
I figured out:  due to the simple common bridge for powering both ends, dialing in on telephone caused a voltage rise for each break, and on hang up, and the connection stay until both ends hangs up.
This was used to sense the voltage rise, and give pulses on the POTS side of the trunk. (Relay D, and contact set d1)
When hanging up, the voltage rises, and D opens the POTS circuit....

Another problem are to connect a dtmf to pulse converter, the original dial tone (buzz) disturbs any receiving of dtmf. I will have to put in a SMART1 adapter who makes its own dial tone, and then you will loose the original tone
The dial tone is a constant tone of this busy tone. soundcloud.com/d_s_k-2/busy (horrible)  It sounds some different in the phone.

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: twocvbloke on August 14, 2014, 04:18:02 PM
The dial tone is a constant tone of this busy tone. soundcloud.com/d_s_k-2/busy (horrible)  It sounds some different in the phone.

Sounds like a very rough version of the UK dial tone, as if it's just a bit too loud, you could probably attenuate it a bit just to calm it down a tad... :)
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on August 14, 2014, 04:58:30 PM
Not easy, but possible. Dial tone: "summe-tone" are made as in diagram:
dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: twocvbloke on August 14, 2014, 05:08:04 PM
You could probably get a Logarithmic Potentiometer (such as the 10kOhm one I use as a line attenuator for my turntable to calm down my preamp's output) and find an optimal resistance at which the tone doesn't sound distorted and rough and seal the deal with an equivalent resistor fitted in place... :)
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: Owain on August 14, 2014, 06:12:53 PM
the original dial tone (buzz) disturbs any receiving of dtmf.

That used to happen with standard UK 'purr' dialling tone too; hence the new whistling dial tone on MF-capable exchanges.
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: Weco355aman on August 14, 2014, 06:52:26 PM
Maybe you could lower the Dialtone volume  a little and then the TT conv would work.
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on August 16, 2014, 02:39:09 PM
This are not easy, but you may test by ringing SIP Broker number *011-478
When you get the purring dial tone 3 long dtmf tones: 333 will give a ringing.  911 or 912 will give a busy signal.

I have to ask someone to provide me with a C*NET number for this. (Don't know who)
Or via one of this gateways from a regular phone:  http://www.sipbroker.com/sipbroker/action/pstnNumbers (http://www.sipbroker.com/sipbroker/action/pstnNumbers)

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on August 17, 2014, 05:07:28 AM
I have registered at least one has tested, and I forgot to mention: I would like feedback, and hints here or as a PM.
Thank you!

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on September 11, 2014, 01:43:35 PM
 :) I hope I have reached the goal, Its working!

When you dial in from internet or regular phone, you get the real purring dial tone.
If you send the push button tones (DTMF) 2-9 or 12-19 you still hear the dial tone a few seconds, then you hear the pulses, the switch are working, and you get the extremely low ringing signal. Its 25HZ and should be out of the band transmitted, but you hear it. The volume depends of the REN load in the other end.  9=busy 6 are my phone on my desk, (AE40).

Please do not ring after 10PM CET

 My SIP Broker number are  *011-478
Or via one of this gateways from a regular phone:  http://www.sipbroker.com/sipbroker/action/pstnNumbers (http://www.sipbroker.com/sipbroker/action/pstnNumbers)

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on October 01, 2014, 03:53:47 AM
Yes it is working, and it is a loong timeout after dialing C*NET 1-857-1116 then you get a ring, and the SXS answers with purring dial tone. Dial the extension you want and again wait for about 7 sec. You will hear the pulses, and then it connects you.

ext 9: always busy,  14 and 15 telephones in my garage, please dial 6  only at Norwegian day-time. (6 My desk)

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on October 04, 2014, 04:41:09 AM

 :) :) :)  (https://lh6.googleusercontent.com/-z-Vcijxzbc0/VDGOHW6fx7I/AAAAAAAAKwE/1i_ORZ6CLBE/w456-h457-no/ULster7_1116.jpg)I feel I've really reached the goal  :)

Its working, on net and I have got nearly 60 test-calls to non answered extensions as 9 (busy) and 3 (ringing) during the last week.   
Very little feedback, but everything looks like its working. The next could be a voice quality test,  listen to a radio station or??? (at least it should be quite simple)

Most of the calls comes during my night, so its probably you over there calling.

Now I got another reason for invite you to join C*NET (https://www.ckts.info/)  and of course Telephone collectors international and read Switchers' Quarterly (http://www.telephonecollectors.org/) even when this forum has a more friendly layout.

Together its perfect  ;)

Thank you! without you and the other forums i would never even thought about getting this up and running.

dsk

Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on March 23, 2015, 04:02:19 AM
This design are from approx wwi but it works, and are just implemented as my home telephone system. The outbound calling are still a problem, and does only work on the shortest lines. My son noticed at once the different ringing, 25Hz vs 20Hz :-)

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on March 23, 2015, 01:19:19 PM
The ringing tone are depending on the ringer current, my "modern" phones with more than 1000 ohms ringers does not draw enough current.  That is a problem I never have considered as a possible problem!

dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on December 12, 2015, 09:38:24 AM
How does the ring look?
Tried to catch some data via the PC sound card and the Visual analyzer (freeware), and here is the ring, generated by a vibrator, the cadence is controlled by a relay and capacitor:
dsk
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on November 12, 2018, 02:40:35 AM
I had to give up my inward trunk.
 :(


dsk ;)
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on September 27, 2020, 03:16:10 AM
Even the first trunk failed, but I have redesigned it and for the moment this is working for outgoing calls. (http://www.classicrotaryphones.com/forum/index.php?action=dlattach;topic=4185.0;attach=225506;image)
Title: Re: Elektrisk Bureau PAX SXS with drums
Post by: dsk on November 02, 2020, 06:36:03 AM
I learn something all the time, but that the ringing sounds different depending on the other end.

Here I have first an electronic ringer from 1980, then 2 old phones so they will draw pretty high REN load, and at last no load.
https://soundcloud.com/d_s_k-2/depending-on-ringerload
dsk