This not important ....

[clint_flick]

Hi

Vodafone VOIP adapter, by whatever name ..........

Ignore the orientation.

But it seems that a capacitor is fitted which may make it polarity conscious.

A pair of wires to 2 and 5,  RD & GN although I cannot assign pin numbers to colour.

Otherwise I believe it is a simple pin 4 & 5 OUT US style;   to  2 & 5 UK style IN.

[Jayach]

Your pictures haven't been moderated yet, but I've always wondered about the polarity of the capacitor, but somehow it doesn't seem to matter.

[Cynric]

It's probably there to suppress noise.

[Ripshod]

Yeah, the old bell (or ringer) capacitor. Sadly it's still needed on some phones.

Note the "NP" marking. This means it's non-polarised, which means it doesn't matter which way round it's used. I've come across quite a few bt sockets that are incorrectly wired so that's probably a good thing. 

[Cynric]

Yes, there are no polarity markers on the rim. Originally the legs would have been the same length.

[Jayach]

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@Ripshod wrote:

Note the "NP" marking. This means it's non-polarised,

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How did I not know that! I had assumed as it looks like an electrolytic capacitor, it had to be polarised.

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@Ripshod wrote:

I've come across quite a few bt sockets that are incorrectly wired so that's probably a good thing. 

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I thought the incoming polarity reversed on every call?  Something to do with CLI.

[Ripshod]

Negative. Since the birth of telephony the phones have needed power to operate. This power can only come from the phone line. Typically thus is anything from 38 to 50 volts DC. Polarity was important as you can imagine.

Recent, but pre-digital phones started to have their own sources of power along with dc filtering on both wires, and so polarity became less important. CLI was born and was just a series of audio pulses the handset received before the ring signal, and the number was available before you answered.

The birth of dect brought digital signalling with it - no accident that the internet moved to adsl at roughly the same time. But that still had a lot of development before dect became publicly available on exchanges. The old analogue system ran alongside for a good many years.

Even today ICT engineers are taught that the primary colour goes to "A", most of the errors coming from builders and the more "knowledgeable" but equally ignorant electricians.

[Jayach]

Not disagreeing, and I'm not (and never have been) a telecoms engineer, but what is this all about then?

https://www.ixysic.com/home/pdfs.nsf/www/an-118.pdf/$file/an-118.pdf

[Jayach]

I know we have to not believe everything A.I. tells us, but.... 

[Ripshod]

Look closer at the info you posted.

"Pulse width is approximately 2mS at TIP/RING voltage of 15V and Values shown. 16mS at TIP/RING voltage = 48V"

It's not a true reversal, more a dip to 15V.

As an aside I find it interesting that they use the LDA100SM, as being bi-directional it's relatively immune to reverse polarity.