Author Topic: stray voltages in 1A1 1A2 systems  (Read 897 times)

Offline Babybearjs

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stray voltages in 1A1 1A2 systems
« on: December 16, 2016, 04:11:44 PM »
I was posting a thread about a crosstalk problem.... and am having issues.... anyway, the report came back about stray voltage on the phone line... and heres the question.... On the 1A1 200 series KTU's... were there any history of voltage leakage onto the phone line? I am looking at my setup and wondering if my 1A1 system is just too old and need to change it out to my 1A2 system. I'm running a VOIP phone line and the system is very sensitive. if everything is wired correctly, has there ever been history of the A-Lead voltage, lamp feed or signaling voltage interfering with the basic operation of the system? I'm trying to understand why my system all of a sudden has started to act up and if I need to change over to a newer system. my IW is the problem right now. that will get fixed soon... but if everything checks out OK and there is still leakage.... what should I look for?
John

Offline dsk

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Re: stray voltages in 1A1 1A2 systems
« Reply #1 on: December 16, 2016, 04:14:16 PM »
Could you "isolate" it with a wireles phone jack?

dsk

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

Offline rdelius

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Re: stray voltages in 1A1 1A2 systems
« Reply #2 on: December 16, 2016, 05:12:02 PM »
I would disconnect the telephone sets and see if the problem goes away.I have seen switches in telephone sets get leakage  from high voltage exposure.Remember that used sets were turned in for faults , not just because age or colors etc.If punch blocks,look for stray wires

Offline twocvbloke

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Re: stray voltages in 1A1 1A2 systems
« Reply #3 on: December 16, 2016, 10:33:06 PM »
It could be something on the component level, such as leaky diodes and tired capacitors allowing current to flow the wrong way, after all, the systems were technically never meant to work for this long before needing major electrical overhaul at the component level...

Offline Babybearjs

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Re: stray voltages in 1A1 1A2 systems
« Reply #4 on: December 17, 2016, 05:28:04 AM »
the punch blocks are suspect.... I have about 6 of them under the house. I've been noticing that the neighbors cat has been crawling under the house through a cracked vinyl siding panel.... so once the weather starts to get warmer I'll be able to troubleshoot the issue.... at writing this, its in the single digits here in Boise, ID. Brrrrrr! I will keep you all updated as to the situation....
John

Victor Laszlo

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Re: stray voltages in 1A1 1A2 systems
« Reply #5 on: December 17, 2016, 07:23:00 PM »
The first answer is a bunch of questions: Do you have a meter? Do you know how to use it? Have you tested the system, with the T&R turned back at the point that the line enters the system?  Only you can tell us where the voltage (or ground, or short circuit) is coming from. Put the meter across the incoming line wires and from each line wire to ground. Manipulate the keys on the phones, in as many combinations and permutations as possible. If you see something suspect, remove the phones from the system and start over.

The new VoIP sources of "fake" dial tone are much less forgiving than sources of real dial tone.  I echo what the other guys have said: you may have leakage, but not directly from the system. Could be moisture at terminals, in cables themselves, at amphenol plugs, inside the keys of the phones, etc.  The thin piece of foam plastic inside the front of the 6-button key in a 56x/256x set, used to support the key contacts, is notorious for attracting moisture.  Isolate and test, test, test with the meter.

This is a good time to remind everyone who plays with these systems that a BSP job calls for home runs of cables, each one terminated ("headed up") on a 66 block. All features provided by cross-connections from the KSU feature blocks to the station cable blocks. Bridging clips used to isolate the pairs, etc.  If a job is done correctly at the beginning, it will be easy to do trouble-shooting later.
« Last Edit: December 17, 2016, 07:28:45 PM by Victor Laszlo »

Victor Laszlo

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Re: stray voltages in 1A1 1A2 systems
« Reply #6 on: January 10, 2017, 05:59:59 PM »
Well, that was a huge waste of my time and electrons. 

Offline Doug Rose

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Re: stray voltages in 1A1 1A2 systems
« Reply #7 on: January 10, 2017, 06:22:50 PM »
the punch blocks are suspect.... I have about 6 of them under the house. I've been noticing that the neighbors cat has been crawling under the house through a cracked vinyl siding panel.... so once the weather starts to get warmer I'll be able to troubleshoot the issue.... at writing this, its in the single digits here in Boise, ID. Brrrrrr! I will keep you all updated as to the situation....
You have 66 blocks under the house.... in the open....that a cat can get in. Doesn't sound like a pristine crosswire field to me. Moisture and 66 blocks do not mix.

As an wise man once said to me, "I thought you were good at this stuff!"
Kidphone