Re: 3 new messages in 1 topic - digest

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Aug 17, 2008, 12:39:11 PM8/17/08
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I recently restored a 555 for a guy in central FL,  Arthur and Dave have you on the right track, but one other thing to remember is that the plugs need to be polished bright or you will get noisy connections.  I also used a Dremel tool with a pointed cloth tip to burnish the sleeves of the jacks as well, do not go in to far or you wil snag on the ring and tip contacts.  Sometimes those are a bit crusty too so I use a small burnisher to reach in the jack hole and clean the tips of the springs.  Do not use emery board, only the metal rough face type.  Emory or diamond will lodge in the metal of the spring and create points of insulation. (not good).  The extensions have power fed to the lines (extension) through their lamp (2Y) so if a bulb is burned out, you cannot get a signal from that extension.  They are always appearing on Ebay so extras are not hard to find.  There are two types of trunk module, early ones use grounded ringing and that means that the board +24 must be grounded to earth connection (ground of AC outlet)  If you have the other (newer issue) modules they will ring on loop with no grounding necessary.  I don't recall the circuit number (I am not at home this week) but the ground version only has one varistor (small glass envelope with bead in middle enclosed in a plastic sleeve with wire out each end) and the loop version has two.
 
I have prints and the Circuit Description pamphlet in FL if you need copies.
 
Keith Cheshire
 
PS as Art said, where are you, I am in NC and FL depending on month!
On Sat, Aug 16, 2008 at 5:11 AM, telecom_museum group <nor...@googlegroups.com> wrote:

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Today's topics:

* Setting up 555 Switchboard. Need info - 3 messages, 3 authors
 http://groups.google.com/group/telecom_museum/browse_thread/thread/64f5042c62a85f86?hl=en

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TOPIC: Setting up 555 Switchboard. Need info
http://groups.google.com/group/telecom_museum/browse_thread/thread/64f5042c62a85f86?hl=en
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== 1 of 3 ==
Date: Fri, Aug 15 2008 1:42 pm
From: Jaun


(First post) Since I have some basic understanding of voice and data
systems, as a "volunteer," I have been asked to set up an old  555
Switchboard display in a new museum annex. I have no experience what-
so-ever with the switchboard so any information will be appriciated.
The unit is complete and was working when removed from service many
years ago. We do have some basic line drawings but that is about it.
Basically I would like to power it up (lights, etc) and  would like to
have it  function (make patch connections, etc ) for at least two or
three remote (initiate/answer , ring, etc)  phones.  Is there a "quick
and dirty way" of doing this ???  As mentioned any suggestings would
be appriciated.   Thank you..
 John





== 2 of 3 ==
Date: Fri, Aug 15 2008 2:14 pm
From: Mus_PEI


Hi John:

Jaun wrote:
> (First post) Since I have some basic understanding of voice and data
> systems, as a "volunteer," I have been asked to set up an old  555
> Switchboard display in a new museum annex. I have no experience what-
> so-ever with the switchboard so any information will be appriciated.
> The unit is complete and was working when removed from service many
> years ago. We do have some basic line drawings but that is about it.
> Basically I would like to power it up (lights, etc) and  would like to
> have it  function (make patch connections, etc ) for at least two or
> three remote (initiate/answer , ring, etc)  phones.  Is there a "quick
> and dirty way" of doing this ???  As mentioned any suggestings would
> be appriciated.   Thank you..
>   John

When I set up my 555 for my museum, I used a power supply and ring
generator for powering it, and mounted them on a plywood shelf on the
bottom frame. The connectons to the phones are done using a 66 block
mounted on the wall, and connected to the board using a cable with
matching male and female amphenol connectors. I will look to see if I
can find photos taken at the time, and will send them to you. These
photos will show you the connections to the strip at the bottom for
the power and ring cennections. The lines should be clearly marked on
the block.

Quick and dirty way of doing it, no, but not terrifically difficult.

Dave



== 3 of 3 ==
Date: Fri, Aug 15 2008 7:14 pm
From: "Arthur P. Bloom"




Where are you located?  It might be easier to help if one of us is
close enough to travel to you.

The switchboard uses a 20B2 Power Unit, or equivalent key system power
supply. That is the Western Electric model number.  The switchboard
itself is simple to power up. Although it has been quite a number of
years since I have worked on one, I believe that there are terminals
in the rear that are labelled BATT ,GRD, GEN, GEN GRD.  BATT gets -24
VDC filtered battery, GEN gets 90V @30 Hz for ringing.

The trunks and stations are also labelled, or they are terminated on a
50-pair cable that is probably cut off on the board that you have.  If
you call me at 631-749-0100 (anytime) we can determine what you have,
what you need, and whether I have a power supply for you.

Arthur P. Bloom, Curator,
Shelter Island Telephone Company Museum

PSTN 631-749-0100
CNet     749-0100




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