Getting matching transformer from telephone

Don't confuse him with facts. He has trouble breathing and typing at the same time.

Reply to
Michael A. Terrell
Loading thread data ...

We *were* talking about the impedance as presented to to the input of a mixer or whatever, i.e., yes, after the internal transformer, not the impedance of the ribbon itself. The once very widely used Reslo RB/L series was specified as 30-50 ohm

Did it suggest anything other than that in the given description?

It is always grounded, directly or indirectly, otherwise the screen fails to be effective.

So how does phantom power work then? You stick a voltage down the signal leads in parallel and the the return is via what?

If you were even born more than 35 years ago how come you know so little?

Why do you think people such as

formatting link
and others are still manufacturing and selling them, even introducing new designs.

At a one-off price of around 20-30 quid they must be manufacturing them in "quantity"

R.S. Components are a hard-headed, very commercially minded electrical/electronics distributor, who only stock stuff they can shift in quantity, yet they still list a centre-tapped primary, microphone transformer

In an article in Electronics World April 1991, Douglas Self of Soundcraft stated "It is now rare to use input transformers...." It is clear, therefore, that they were still being used, even if only in specialist applications. That is a bare 18 years ago.

Reply to
Stuart

WOW. I'd never have guessed !

What a load of Bollocks !

Transformers are neither needed nor used any more.

Graham

Reply to
Eeyore

Is that how long you've been practicing telephony ?

Graham

Reply to
Eeyore

"Howls of derisive laughter" Bruce:

Graham

Reply to
Eeyore

Want to to see the schematics ? I'm sure I still have them here somewhere.

Graham

Reply to
Eeyore

You are full of BS.

Reply to
Eeyore

Minority use even then.

Try and think WHY.

Graham

Reply to
Eeyore

In article , Eeyore scribeth thus

Umm... beg to differ .. they are used for 2 and 4 wire analogue or analogue over digital voice band private circuits...

And they do sometimes use DC blocks but rarely now as point to point DC available paths are rather rare unless on the same ends of the serving exchange..;)...

Reply to
tony sayer

I thought we were talking POTS ?

Graham

Reply to
Eeyore

That is a sign of dementia.

Reply to
Michael A. Terrell

Well, lets see now.

Because Graham doesn't like being proved wrong?

Because I didn't spend 20 or more years of my life measuring and testing audio systems, equipment and GPO lines that were all designed for 600 ohm characteristic impedance (among other things)?

Because until the 1980s (I think it was) The GPO/BT didn't have a monopoly on telecommunications, including the distribution of audio down its many miles of cable? [1] Minority use?

Because the BBC didn't have a number of large and small studio complexes where 600 ohms was the norm (Not anymore but it was then) for audio?

Because even the most modern audio test equipment doesn't have facilities for measuring 600 ohm systems? - Oh dear, another wrong answer.

Because this isn't a binary group and I don't have a website on which post proof positive that you are wrong but would you would ignore anyway?

However, let me try this quote on you. From "Studio engineering for Sound Broadcasting" - Iliffe - 1955 (that's about 45 years ago) p20: "The chain incorporates a Post office line and to avoid confusion.......In the early days most Post office lines were open wire lines and all these had an impedence of about 600 ohms"

Stuart

[1] Remember, we were discussing the history of why 600 ohms became the standard impedance for *audio distribution*. Not teleprinters, telegraph systems or even telephone wiring; or why the microphone input of a mixer desk is around 2k ohms.
Reply to
Stuart

In article , Eeyore scribeth thus

Yeah .. sounds abaht right;-))...

Reply to
tony sayer

In article , Stuart scribeth thus

Kingston telecoms anyone;)..

...alright not that much of the UK!....

Reply to
tony sayer

Or rabies.

Reply to
krw

Actually I did have them in mind whilst composing my reply but forgot while I was typing. :-)

Reply to
Stuart

Oh he can do that, albeit through the mouth. Because Dumb Donkey is a mouth breather, he drools as he types (loses control over other bodily functions, as well). The result is what you see here.

Reply to
krw

Yes, I would like to see them. Probably better than the Sunday funny paper.

Reply to
Floyd L. Davidson

So you admit you cannot support your claims.

Reply to
Floyd L. Davidson

He can't even support his three chins.

Reply to
Michael A. Terrell

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.