Talk:4P4C

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Real?[edit]

Registered Jack claims RJ9 is an "unofficial" type. Is that right? What's it's "real" name? —Ben FrantzDale 18:45, 12 September 2006 (UTC)

RJ9 and RJ10 both incorrectly refer to the "handset cable connector" designed by Bell Telephone in the 1970s. it does NOT have a 'Registered Jack' (RJ) designation because it is not intended to be connected directly to a phone line. (Though the plug *DOES* fit in an RJ-11 jack.) As far as I'm aware there is no industry-agreed standard for naming this connector, so everyone seems to call it what they want. There was a discussion about this on the classiccmp.org mailing list a few years ago. In my opinion, this whole page should redirect to the 'Registered Jack' article.--Lord Nightmare 03:34, 3 December 2006 (UTC)

Handset cable connectors are smaller than RJ11 connectors used to plug a telephone into a wall outlet. Although one can insert an "RJ9" or "RJ10" connector into an RJ11 outlet, it will fit loosely and will most likely mismate or fail to mate with the receptacle contacts. —QuicksilverT @ 00:46, 14 December 2006 (UTC)

The "rj9" jack is probably named by the manufacturer(s), i.e. Amp or ? The article should be made part of the "RJ" article. The RJ9 is not used for anything else but telephone handsets. A simple explanation of why it is not an "official" RJ would be sufficient to make it's place in the telephone world clear. A separate article is splitting hairs. Randyleepublic 00:57, 22 December 2006 (UTC)randyleepublic

While the RJ9 designation may not be "official" or de juro it has become, by common usage, de facto.

Image Caption incorrect[edit]

"4P4C modular connector as would plug into an RJ9 jack"

Should that actually be:

"4P4C modular connector as would plug into an RJ9 socket"

?

Many errors in description of handset connection[edit]

There are many errors in the description of the wiring of the handset connection:

  • Not all manufacturers wire the handset as described here, quite often the speaker (actually transducer) uses the inner wire pair, not the outer wire pair. Even other configurations are sometimes used, there is no standard, except that the described situation is more used than others.
  • Its not true nowadays that the polarity of the microphone is insignificant! That might have been true in the past when carbon microphones were still in use, but almost all telephones now use FET-microphones, and these are polarized. When the polarity is reversed the microphone will not work.
  • I don't know what the resistor in series with the speaker is doing, normally handsets do not use a loudspeaker or a series resistor, they use a device called a "transducer", this is an encapsulated speaker, so sound pressure cannot enter the inside of the handset where it might reach the microphone, causing unwanted feedback.

Mahjongg (talk) 13:25, 14 January 2010 (UTC)