[ProAudio] Western Electric 111C transformers

Tim Požar pozar at lns.com
Wed Feb 2 11:41:29 PST 2022

They also had to make sure the lines were not loaded (3Kc limit) and not 
bridged or tapped to screw up impedance, make the circuit an antenna, etc.

Try to find someone that would know how to deal with these circuits now. 
  Let alone 3002 circuits, ISDN or even T-1s.  The RBOCs don't have a 
clue about these lines anymore.


On 2/2/22 6:07 AM, Bob Katz via ProAudio wrote:
> Gawd, this goes back! Now I remember. In the 70's, when I worked in 
> Radio and TV, a little before we got some portable "high fidelity" 
> microwave relays and long before we got "the Internet" We used to order 
> 5 kc mono and very occasionally 15 kc stereo lines to do remote symphony 
> broadcasts from Bushnell Hall in downtown Hartford via Telco. They were 
> VERY expensive and you had to order the lines weeks in advance so that 
> Telco could "do their magic". I know that Telco cranked up the EQ 
> (actually they rolled off the bottom to get more top) and so the level 
> was effectively low and the SNR was terrible over a 5 to 10 mile copper 
> run from the hall to the station....  which may have gone through a 
> couple of COs. I never looked in the back room to see the "high 
> fidelity" demarc where I'm sure I would have found those 111Cs!!!!
> I'd hate to see the phase shift....
> You guys are taking me WAY WAY back.
> Bob
> On 2/1/22 3:10 PM, David Josephson wrote:
>> Because the telephone company was how radio stations sent program 
>> material from remote broadcasts to the studio, and from the studio to 
>> the transmitter. Many of the 111Cs people have collected were 
>> abandoned on telephone backboards in radio stations.
>>> On Feb 1, 2022, at 6:51 AM, Bob Katz via ProAudio 
>>> <proaudio at bach.pgm.com> wrote:
>>> I will definitely post my results.
>>> But first I have to find a place in my crowded system to put these 
>>> big puppies. They are certainly among the largest piece of audio iron 
>>> I've ever seen. I don't understand how a telephone company in the 
>>> middle ages decided to make a transformer with such amazing bandwidth!
> -- 
> If you want good sound on your album, come to Bob Katz 407-831-0233 
> DIGITAL DOMAIN MASTERING STUDIO Author: *Mastering Audio* Digital Domain 
> Website <https://www.digido.com/> No trees were killed in the sending of 
> this message. However a large number of electrons were terribly 
> inconvenienced.
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