Re: 555 Switchboard - Iowa

[Arthur P. Bloom]

The test board was a central office piece of equipment and has nothing
to do with the switchboard. There would be no advantage in trying to
get it hooked up.

The switchboard, however, is "subscriber" equipment, that is, used on
a customer's premises, so getting it hooked up will be historically
accurate and significant.

APB

On Aug 17, 3:42 pm, Jaun <jrpor...@yahoo.com> wrote:
> Thanks for replys..  We are located in Eastern Iowa.  The switchboard
> will be returned to the refurbished headquarters office building of
> the old Clinton Engines Company factory site.  (http://www.clintonengines.com/index.html)  As a volunteer, we installed the
> modern voice and data cable system to the building...  Since we knew
> what a screwdriver  was, it was assumed that we must also know about
> old switchboards as well. Basically, I said I would give it a try,
> etc, etc..  What we have is the 555 (  http://img.photobucket.com/albums/v511/cavesrd/Switchboard.jpg
> ) and what appears to be an old  CO local test panel  (http://
> img.photobucket.com/albums/v511/cavesrd/WETestset.jpg ) Since the test
> unit was with the switchboard... I am hopeing it can be used in
> concert with it somehow..    The cables were simply cut off on each
> piece of equipment. I happen to come across this fourm while
> attempting to learn about the switchboard and thought I would give it
> a try... ,etc..  As mentioned, we hope to have 2 or 3 stand alone
> desksets connected to the board.  Just something to give the public
> working (and possible hands on) knowledge of the system,etc..
> If I can figure out a power source, a ringing generator (?) and the
> interconnections between the remote phones and the board... That will
> be as far as it goes.
> I look forward to learning about and working on the system...
> Thanks again,
>   John

[Arthur P. Bloom]

Are you sure that the board is a 555, and not a 556? Check the black
instruction card that is fastened to the front of the board, behind
the cords. It will have the model number, and the date of manufacture,
in the format M-YY.

A 555 has rows of jacks, one jack per manual extension, and with each
jack, a designation card and an associated lamp that lights when an
extension goes off-hook. It is strictly a stand-alone manual board. I
do not see any lamps on your board.

A 556 looks almost the same, but has no station lamps. It is used as
an attendant (telephonese for "operator") position, behind and in
conjunction with a dial PBX, such as a 701 or 740 PBX. There are no
busy lamps, because the extensions do not go off-hook to reach the
attendant. Instead, each extension gets a dial tone, and station-to-
station, station-to-trunk, and station-to-attendant calls are dialed.
The Attendant does not see a busy lamp per station, but relies upon a
technique known as a "sleeve test" to determine if an extension is
busy. Incoming calls to the trucks are handled by the attendant as
would calls on a manual PBX. The attendant answers with the left cord
and places an inward call to an extension with the right cord.

If I am correct that you have a 556, then getting it to work, even for
demonstration purposes, is going to be a more difficult, if not
impossible, task.

It would be helpful, along with telling us what model number is
printed on the board, if you could ask anyone who worked in the plant
if there was ever a room full of gray telephone switch gear.

Please keep us informed.

Arthur

[Arthur P. Bloom]

Message #2

There is more evidence, as I peruse the photo of your switchboard,
that it not a 555. At the upper left hand corner of the board, there
are what appears to be traffic registers. There would be no reason to
have registers on a manual board, because their function is to record
various states of the switching equipment that is associated with the
board. The registers probably have designations as follows: AFB, ATB,
LCB, FA, CB, PS, etc. These indicate to repair personnel and traffic
engineers how many times All (line) Finders were Busy (AFB); all
trunks were busy (ATB); the last connector was busy (LCB) how many
fuse alarms (FA) occurred, how many call blocks (CB) occurred, and how
many times there was a permanent signal (PS).

Traffic registers = switching equipment = 556 PBX

Q.E.D.

[William Geurts]

Every once in a shile a 118A frequency generator comes up on e-bay or on the list server.  You might even be able to bum one off a local telephone contractor that has a bunch of old key systems gathering dust.  One of those would be ample for what you are doing and very small.

 

Bill Geurts

 

On 8/18/08, John <jrpo...@yahoo.com> wrote:

Well....  you guys are correct !!
The switchboard in question is not a 555, it is in fact, as
suggested, a 556.
Hopefully we can still set it up without too many problems. We went
back to the board to double check things and noticed that it has a
hand crank generator at the right side. If noting more maybe I can
make connections to a remote bell using it until we can come up with a
better ring generator, etc. As mentioned, all we really want (at this
point) are two or three  remote phones and the switchboard to light up
on those lines, etc..
If nothing more.. we are learning about what we.. 'don't have.'
And, that is a lot more than we knew when we started this project.

Keep the suggestings coming.. all are appriciated !!

Thanks again,
John



........On Aug 17, 5:19 pm, "Arthur P. Bloom" <i...@m35products.com>

[Arthur P. Bloom]

You are trying to get one type of machinery to do something it never
was intended to do, and we don't want you to get discouraged. I
installed, repaired and maintained these for a living. Beware of
schemes that sound easy, but will just get you frustrated. There are
some serious flaws in your otherwise well-intentioned plan.

A 118A frequency generator is only half of what you will need. You
will need a talk battery supply, as I mentioned above. It needs a
filtered 24 volt supply.

You could ring extensions, and have them talk to each other. You will
have a tough time doping out the station circuits, without a print. I
don't have a print, but someone might. Then you will need to acquaint
yourself with a whole new technical language and set of drawing
protocols to be accustomed to. We can help, but absent a hands-on
helper, you will find it difficult.

You could wire an incoming POTS line to a trunk circuit, and the trunk
lamp would light up, and calls could be passed to an extension. But
you will not be able to get its extensions to light up, because there
are no lamps on the station circuits, as I mentioned above.

I have a suggestion. A look-alike board, the 555, is what you need,
and the public will not be the wiser if you go with that
substitution. 555's are plentiful and occasionally inexpensive.
Check Ebay. There are several of us who would like to have a 556. I
have a 200 line step-by-step switch that could use one, in fact.

Try to find a 555, and maybe a swap or a deal could be arranged, in
your favor.

APB

On Aug 18, 3:54 pm, "William Geurts" <billgeu...@gmail.com> wrote:
> Every once in a shile a 118A frequency generator comes up on e-bay or on the
> list server.  You might even be able to bum one off a local telephone
> contractor that has a bunch of old key systems gathering dust.  One of those
> would be ample for what you are doing and very small.
>
> Bill Geurts
>

> > > Q.E.D.- Hide quoted text -
>
> - Show quoted text -

[Mus_PEI]

At the request of John (Jaun), I have removed his posts from the 555
switchboard threads.

Dave

[Arthur P. Bloom]

Without the original questions, it probably would make sense to delete
the answers, too.

APB

[Mus_PEI]

Hi Arthur:

On Aug 31, 2:59 am, "Arthur P. Bloom" <i...@m35products.com> wrote:
> Without the original questions, it probably would make sense to delete
> the answers, too.

Yes, and no. There was a reason the gentleman wanted his posts removed
which he asked me to keep confidential, but the answers themselves may
be of assistance to others who might be in his situation. So in the
interest of keeping the excellent advice he was given by the members
of the group, I decided to leave the answers posted.

Dave

[Arthur P. Bloom]

"There was a reason the gentleman wanted his posts removed

which he asked me to keep confidential."


What an intriguing remark. I can't begin to fathom what "confidential"
reason one would have for not wanting one's questions about a 50-year-
old PBX to appear on an obscure forum that is read by maybe 27 people.

I see that I have apparently scared him away completely. Too bad. I
was hoping to hear some good news about his display.