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GPO Candlestick Problem

Started by Dan, August 08, 2009, 07:04:24 PM

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Dan

About a year ago, I got a GPO Candlestick #150 off Craigslist. It is hooked up to a WE 685A subset and has a bakelite Kellogg reciever with a modern ITT  earpiece transmitter. So it's a bit of a mutt.

The problem is , if you plug it in you can dial out ok, but the phone will not hang up. The hookswitch and cradle , it you jiggle it, always stay on. I think it is a contact issue. When I have worked on electromechanical pinball machines, I have cleaned the contacts to get it to work, but I was wondering if this is similar?

Perhaps Stephen or Scott (GPO man) could help me. It looks like a daunting task to take these apart. Here's a website to help you and give information. Thanks.

http://www.britishtelephones.com/candle1.htm
"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

Stephen Furley

Dan,

Sam Hallas  also has information on stripping down a 150 in the 'Let's take a phone to bits' section of his site; there's a link to it on this page:

http://www.samhallas.co.uk/telecomms.htm

I have to admit that I've never seen the inside of one; mine has not arrived yet, though the cheque has just shown up on my bank statement, so it should be here soon.  Sounds most likely to be a hook switch issue, but it's possible that there's a leakage through it somewhere that's drawing enough current for the exchange to think it's off-hook when it's not.

Does it seize the line as soon as you plug it in, or only when you take the receiver off-hook?  Is it wired up correctly?  Sam's 'take it to bits' document includes the wiring  diagram from N250; Is yours connected up the same way.  I don't know anything about the WE 685A subset, is it reasonably similar to the Bellset 1 or 25 shown in N250?  I believe that the British candlesticks were very similar to the American ones, and indeed some of the earlier ones were actually imported from AE.  Many of the 150s were converted from earlier, non-auto models.  Since the thing is made mainly of metal, unlike almost all of our later 'phones, is it possible that something's shorting out against the inside of the column?

I've never seen a candlestick actually in use, though some must have survived into my lifetime.  Some of the next generation, the 162 pyramid 'phones were still around into the '70s.  The British Railways 'Modernisation Plan' was launched in 1955.  British Transport Films made a number of productions about it under the title 'Report on Modernisation'.  The first of these was released in 1959, and the second in 1961, and in one of these, I think the first, There is a shot of the inside of the control tower of one of the new marshaling yards built under the plan, and closed within a few years.  This 'new' installation featured a candlestick telephone.  It was mounted on one of those extending criss-cross arm wall bracket things, which I've seen in old advertisments under the strange name of 'Wallygraph'.  I suppose the column of a candlestick would be easy to attach to one of these; maybe that was why it was used at so late a date.

Phonesrfun

Dan:

I would say that the biggest problem is the subset.  You are using a 685 which a more modern subset based on the network found in a model 500 telephone. 

From the pictures in the link, the GPO 150 seems to be a pretty straight forward sidetone model similar to the WE 40 candlestick.

I am not saying that it could not be wired to the 685, but I would need to do some thinking to see how to adapt it, if possible. 

If you could get your hands on a 584, 534,334, or 295 you may more success.  If you have Meyer's book, you can see examples on pages 71 and 72.

To know for sure, I would need to see a daigram of the GPO candlestick.  Does someone have access to the diagram of the GPO phone itself?

-Bill
-Bill G

Dan

Stephen, if you plug it in it comes alive just as if you plugged any modern phone in with a jack (with the receiver OFF the cradle). The phone always thinks it is off hook. You can dial with it, it transmits, people can hear me, I can hear them, but you can't hang it up. It can't receive calls because when you plug it in, it acts as if it is off hook all the time. The subset wiring looks good, the wall cord looks good. Inside the phone the wires are all connected in the base to a modern block.

The network is just like a WE 500 (425E actually). Here's some pictures.

Phonesrfun, Stephens link has a wiring diagram for this.

Another important thing to know is the seller siad he had to jiggle the hookswitch sometimes, but it worked great .

Telephone and subset




Network wiring and close up of network




"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

HobieSport

Nice looking candlestick! Are you able to get at the hookswitch mechanism to see why it's misbehaving?
-Matt

Phonesrfun

Dan:

The schematic is pretty standard.  The schematic is of a regular sidetone phone which needs only three wires connected to the subset.  Your photo shows four wires connected at the following points in the subset:

L1
L2
C
R
B

So, I have two questions:

First, can you take the phone apart and tell me to which terminals inside the phone each of those four wires are connected.

Second is more basic, and that is when you take the phone apart and look at the three contacts on the hookswitch, are all three springs opening up when the hook is in the down (hung-up) position?  This might be the more important question.

-Bill
-Bill G

bingster

I'm going to go out on a limb and suggest that it's the subset.  The 685 is a much newer subset that's not designed to be used with telephones which require subsets.  Those older types should use a 534, 584, 634, 684, or one of the oak boxes.  If a 685 is used, there are several wiring changes that need to be made inside the phone to make the setup work.  I'm thinking that the 685 has been used without the proper in-phone wiring modifications, or that the wiring in the subset is incorrect.  Either way, I'm guessing the problem revolves around that subset.
= DARRIN =



Dan

#7
Bill here's a picture of the block under the base. I don't know if this helps. I can slide the hookswitch off the stick, but the block with the electrical tape will have to be disconnected to get to the hook switch .(and that quite frankly, scares me a little bit--)



"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

Dan

Bingster, the seller said the phone was wired by a pretty reputable guy (even though it looks sloppy to me) . He sold me the phone cheap because he hated the weight and overall talking on it.

Bill if you need me to unhook the wires off the electrical taped block to get to the hookswitch , I can do this .

Would the hookswitch contacts need to be rubbed clean (oxidation? )
"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

Dan

#9
Here's a picture of the block with the old electrical tape removed , if this helps (I CAN put back electrical tape, so I'm not too brave here)



The two brown cords are from the receiver earpiece
"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

Phonesrfun

Ay, yay, yay!

That phone has been heavily modified.

In order to check the switch, you will need unhook it and open it up.  I agree, that is a scary proposition.  However, in order to solve the problem, we need to first and foremost find out if the switches are opening.  If that solves the problem, we may be able to stop there.  However, if that doesn't solve it, we need to know if the phone was modified to operate with the 685 subset.  The home-brew connecting block is an off the shelf thing that is not an original part of the phone, and as you can see, the newer wiring to the dial and to the switchhook are also not original.

So, it's up to you.  BTW, I tend to agree with Bingster about the 685 not being compatible with the older sidetone (especially candlestick) phones for reason of where in realtion to the transmitter and receiver the hook switch is located and what parts of the phone are switched.  There have been some threads about that in the club forums over the years, and I seem to remember that it either flat out won't work, or it will work but not optimally.  I just studied the 425 network, and I cannot see a way to do it without some modifications.

It may be that the phone wiring was modified just for th 685.  If that is the case, it may be that we can get it back to working again, but we are now trying to make sense out of someone else's work.

Not the news you wanted to hear.

-Bill
-Bill G

Dan

I'm going to get some masking tape and label all the wires so I can get them back in place once I get them unhooked off the block. I will then show you a switch pic because I don't know what it means when it opens up?
"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

Dan

#12
Here's the switch exposed.





Would the little blue and yellow area that is visible that has metal on the end which could be hitting the candle stick metal somehow be a problem? A guess. Also, if you see the little brown paper between the  switch blades, it's loose and can be removed
"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright

Phonesrfun

So, the question is:

When the hook is in the on-hook (hung-up) position, do the contacts open up completely?

Also check to see that the soldered-on connectors are not inadvertantly touching each other, which would have the same effect as a switch that does not open.

Lastly, can you make out what that reddish or rust colored square thing is in-between two of the contact?  It appears that it is holding at least one set of contacts permanently open.  It may have been modified on purpose to do this.

Is it within your realm of your patience to map out where each wire is connected within the phone and to the block and also to the wires going to the 685?

It may be that the guy modified the switch to go to the 685 the way a 685 is needing it.  That may be why he has only one set of contacts working.  But do check to see that they open up when the hook is down.

-Bill

-Bill G

Dan

#14
The contacts do open up completely when it is hung up(the top two leaf layers move from closed to open) . The red rust square does hold the contacts (layers two and three of the leaf switches)  permanently open , but can be removed. Will this mean if I take it out, the phone will hang up? Maybe this piece of paper is the problem?
"Imagine how weird telephones would look if our ears weren't so close to our mouths." - Steven Wright