Landlinel Telephone Voltage vs Cassette Answering Machine

[Analogue23]

MODs, if this is the wrong forum- please feel free to move-** IGNORE OR DELETE THIS- DOUBLE POST**

apologies as I did not read the instructions- this is a duplicated post- what a doof I am// DELETE

Question: Through a series of logic, I have determined that it is probably the voltage or ??? that does not "Send" (pardon my terminology I am not an electrician) the tone/voltage/whatever it is, down the line of my landline telephone service ( it is *not* VoIP, nor a bundled cable svc- it is solely a CenturyLink copper line/landline ordinary telephone service) there is one telephone only, one telephone jack- so no REN issues there- the issue is:

analogue cassette answering machines do not take messages properly- they either do not take the message, or it is cut off, or it will "pick up", but then cut off immediately. I have tried numerous answering machines- all analog, all cassette, (thanks Goodwill!) yet digital machines do NOT have this problem. I think that it could be some sort of change in Telco's system, perhaps the analog machine is not getting the proper voltage sent through, something that did not happen in say, ten years ago- that perhaps there's been a system-wide change in how the power is sent over the lines?

I worked for a telco as an over the phone tech support, but our training was quite limited to what was available from a pre-scripted intranet portal, no real knowledge was required for the job, so I am not inherently smart on this topic. I just know that somehow, some way! analogue cassette machines do NOT work on telephone systems as they did before. It is as if they are in effect, "forcing" us to migrate over to digitally recorded voice mail message systems as opposed to "home point" of saving messages the old-fashioned way.

I do not enjoy the telco's "offer" of 8 USD per month to have my messages saved, by them- I can and do have a digital answering machine but the voice quality is poor on digital of all brands.

Does any one have an answer to this weird dilemma? I am not certain of what CAUSES this issue, I can only surmise what I THINK is the issue (voltage over the lines, etc)

I have an analogue multimeter and a digital one, and I am not an electrician, just a housewife.. if anyone wants to chime in please do. I'd appreciate any schooling on this! Thank you ahead of time

Kay

 

[Analogue23]

Telephone Voltages-Landline & Cassette Answering Machine Issue

Hi Guys. I tried posting a new thread minutes ago, but I can't see it nor is it in my list.. Admin my apologies if it's here but lost?

I have a landline telco service- One jack, One phone (no REN issues, no FAX etc just one telephone on one jack)

It is not VoIP or a bundled cable TV plan, it is a sole telephone service through CenturyLink copper line phone

It is an oldies 1980s, with the cool loud oldies vintage '80s ringer (not the dual "alarm bells" but still old)

I am in a multi-dwelling unit/Condo, if that matters regarding the voltages from the NID etc

Issue: Answering machines of the analogue cassette variety act strangely on this line, as if they are not getting enough power(?) or some sort of "signal" sent from the Telco that activate "whatever it is" that engages the ans machine to pick up and record messages. Now, digital answering machines work BETTER, but not perfectly! No, I do not wish to subscribe to my telco's offering of 8USD per month(!) Voice Mail plan.

Through a system of trial and error, and *not* using a meter but just trying several ans. machines, I have determined tentatively it is somehow in the system of the telco that prevents the machine(s) from acting normally: the ringer does stop after the programmed "fourth ring pickup" but, the line either hangs up, or hangs up prematurely, or does not somehow "hear" the callers voice. When I tried using the digital machine, it DID do the same thing, but less of it- many times the voice was just garbled. To me, this says it is not getting enough voltage? I am not an electrician nor pretend to be- just a curious tinkerer and bored housewife- who is interested in this mystery.

Now, is it a system wide new thing where Telco's do not use the same voltages as before? Is this a lack of PROPER voltage I SHOULD be having, that I can check, and trouble shoot myself? Is it the Telco using some sort of new lines that are on digital as opposed to analog (sorry if this sounds dumb- I'm not an telecom engineer obviously) that makes it so analog eqpt can't communicate the way they did before?

whether I cannot use a cassette recorder any more is fine, whatever the answer is! I do not care, I only want to know, or be able to find out, what exactly causes this issue in the first place.

Any tips tricks advice is appreciated-

thank you very much in advance- Kay.

 

[BradtheRad]

When your phone is 'on the hook' there is 50 or 60V on your line (two wires coming from the street). Then when you 'pick up the phone' it connects low resistance to the wires. That 60V drops to nearly nothing. It is due to the high impedance somewhere on those two wires (down the street). That's how it worked in vintage (analog) days.

Nowadays it is likely that the phone company changed impedances, either up the street, or in modern phones and answering machines. Therefore a different voltage is present during operation. It's possible your answering machine presents the 'wrong' (too low?) impedance to the phone company. Therefore it is ignored.

One can also wonder about beeps (audible or inaudible) and how they communicate in phones, answering machines, the phone company, and your own machine. We can picture some device producing a beep, which is supposed to signal something or other, but which is misinterpreted by another device. Then things don't go right. Could that be the case with your machine?

 

[FvM]

Analog telephone voltages and impedances are standardized and unlikely to change.

Either something is wrong with your telephone network or with your equipment. There are a few simple criteria that rule the operation of an answering machine:
- ring detect (seems to work)
- line current detection after going off-hook
- voice detection

 

[Analogue23]

BradTheRad & FvM, thank you for your informative and fun (hey, it's fun to ME) replies. I disagree as to the problems being with my equipment- but it's not an impossibility, only because I have tried several machines, and through process of elimination I narrowed it to the line in use (my opinion SO FAR)

is it possible, that it could be the voltage is too low? regarding voltage, I can find the proper volts online - it's not the numbers I worry about, its the logistics if that makes sense.

This looks interesting (FvM's post): - line current detection after going off-hook

I may contact my local phone co, whether they will assist with this issue is a whole new can of worms. Til then, any advice appreciated and read. This is a big mystery to me, one which I won't lose sleep over, but will be annoyed for eons until figured out

 

[BradtheRad]

Then there is the opposite possibility: Your machine presents too high an impedance after answering a ring. As a result the phone company thinks your line is 'on hook', and disconnects you.

This is a difficult condition to test. You need to duplicate the circumstances of an incoming call. When your phone rings, it is because the phone company sends high voltage AC to your line (two or three times as great as the normal 60V). Your machine answers the call ('lifts the hook'), by either closing a relay, or switching on some component. It presents low impedance to the phone company.

Now suppose your machine develops high resistance in a component. It answers a ring, however the phone company sees high resistance in your machine. So it sees nothing on the line. It hangs you up. Possible?

 

[Analogue23]

That's another conundrum BradtheRad- the impedance on the machine. Never thought of that, and considering this as a possibility merely adds a wrench to it! it also puts a kibosh on my Great Telco Conspiracy to get us all to sign up for expensive, and not private, messaging system (not that my messages are anything interesting).

Doubt the telco would assist without the 90$ "in-house wiring service charge", which I know what the answer will be- tech will enter, scratch his head, and sign his time sheet as "Resolved" yet my query is not answered. Off topic, someone has broken into our condo bldg's NID/'phone bank", the miasma of thin phone wires that provide svc to all the landlines in the building. Telco phone tech came out per my request to see if any damage done (twice this week, door lock to phone bank broken, door panel left ajar) he gave it a cursory glance and said Nuthin's Missin' and left.

I am keen on the issue being a phone line- "sending signal" that is changed. Now, do telco's use a digital signal as opposed to analog as they have in the past? is this a thing? I mean is part of the line VoIp, and part copper line? I do know that in my past as an IT help desk tech in the olden days, when connecting FAX machines to VoIP and/or people using Nokia "connected" phones as FAX, the FAX could not "hear" the tones properly, as they were digitally sent as opposed to analog, and subject to loss of specific tones/audio that caused the FAX to hang up. Same reason why alarm techs do not recommend VoIP phones, there's a better explanation for it than I give here. If I am mistaken, please correct me, but I am stuck on this suspicion- it MAY WELL be the impedance as you advise. I am not an electrically wise person but a mere tinkerer so I can only take your advice as you give it.

 

[Analogue23]

I found this wandering around telco information sites:
CPC (Calling Party Control) is a signal sent from most modern electronic COs to indicate that the "Calling Party" has hung up. It's usually called "Open Loop Disconnect" when you're programming telephone equipment. The CPC signal tells the phone equipment that the outside party has hung-up, so it can stop recording to an answering machine or voice mail, drop the call off hold, or just release a line that might be used for dictation or announcements.

In the days before voice mail, CPC was used to tell the 1A2 or electronic key system or PBX that the outside party has hung up when the call was on hold, automatically releasing the line.


so there is some sort of signal that is used with answering machines the telco sends. I figured as much.
" Basically, a answering machine can detect the end of a call two ways, from a lapse of current on the line or from a signal from the provider that the call has ended. For the later to work, your provider needs to be sending that signal, and the machine has to be able to understand it." from a Cox user forum- this deals with machine *not* hanging up, as opposed to hanging up too quickly. I'm thinking it has to do with that very voltage being sent prematurely.
I see this thread has a CLOSED tag on it....

I may look around for telco related forums, but I still will lurk around here for fun in my non-busy times.

Thanks for all the fun guys