Author Topic: Setting timing on a dial - A discussion of Analytical Instruments and Audacity  (Read 2514 times)


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I think the BK 1045's use the same dialing  tolerance as the phone company . If that is the case, then I don't think the tolerance is tight enough for IP.

Just a guess tho,
Jim S.

The specification of the 1045B shown earlier speaks against the first of your statements.  Also my experience dispels that notion.
The specs state, in other words, that a break ration of 30% to 85% is accepted as long as the total dial pulse cycle lasts at least 100 ms, and that the dial speed can be 8 to 20 PPS.  The lower value of the PPS is perhaps not low enough for many old telephone dials, because I have seen many between 7 and 8 PPS, but I don't recall whether I had problems on my 1045A.

But, the same specs appear to contradict themselves, because if the unit accepts 20 PPS signaling, then the pulse cycle can only be 50 ms long, violating the "Recognition Time (end of digit)" of 100 ms minimum.  I am sorry, that is not correct. I misinterpreted that statement.  That specification is the time the unit needs to evaluated the preceding pulse sequence as a complete digit, not the pulse cycle time.
« Last Edit: February 06, 2017, 07:02:18 PM by unbeldi »

Offline dsk

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The specification of the 1045B shown earlier speaks against the first of your statements. 
You are right, and I do not know whats right, telephones collecting is not a religion, it is lots of science, but also experience of whats good enough or not.
I have 2 reasons for adjusting my own telephone dials:
1) Learning by doing.
2) Reapair it if it is not working well enough.

When I first have to do something I want it to be so accurate as reasonable. That gives a speed of 11 +/- 1 pps.
The make break ratio is something i usually do not need to adjust at all, but again if I have to I will get as close to 60% percent break as I can without risk of breaking anything, but I am satisfied up to 67% (UK std) since it never has made problems for me. I even have an old 1920ies dial never adjusted and it works at 50% No need for adjusting as long as my electromagnetical PAX understands it , so do the Dialgizmo and the Mitel smart 1. 
What I know is 15 pps is to fast for my PAX.
I have read here on the forum about problems using rotary phones on some ATA's, and I have an Ericsson exchange not accepted by the  Dialgizmo, but by the POTS line. (I should have used more time to figure out why)

I am so happy with this forum, because I can learn something day by day, and discuss such problems here.   ;)
Please notify me of dead links in my postings.

C*NET +1 999-3011

I have even got a regular New York number :-) 646 570 1796

Offline TelePlay

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    • . . . the times they are a'changing
Just discovered another use for Audacity. I have a Kellogg stick transmitter and wanted to test it for working condition. I attached the two alligator clips normally placed on the dial pulse contacts on the transmitter terminals, started to record in Audacity and was able to record my voice and listen to the quality of the sound on playback.

Not a precise measurement but if one were to use a constant volume sound source placed, say, one inch from the transmitter, the amplitude of the recorded sound file could be measured for a group of several transmitters, a plot drawn for weak vs strong transmitters and after that, a new transmitter could be checked not only to see if it was working but also the strength of the transmitter.
« Last Edit: March 08, 2017, 05:19:35 PM by TelePlay »
            John . . .