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I just bought a GPO phone

Started by LarryInMichigan, December 23, 2009, 06:52:49 PM

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LarryInMichigan

All of this talk by about GPO phones here made me hungry for one, so I just bought this:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170422512346
( dead link 08-09-21 )

I figured that it wasn't the trouble to bid, wait, and hope, for a $6 or less price difference.  They don't seem to show up on this side of the ocean very often.

Larry

gpo706

Hi Larry,

It's a 746, Topaz Yellow (or mustard to you and me) the code on the back is GEN 74 which translates as:

GEC-AEI Telecommunications - Newton Aycliffe, County Durham, from 1974.

There are two versions of the standard 746, MK1 & 2, slightly different case mouldings, see here:

http://telephonesuk.co.uk/phones_1960-80.htm#746

I have 2 same colour, didn't realise mines were MK1 till I saw this page and had a very close look. (All the rest I have are MK2's).

Price seems fair for it, you can take it apart and add all sorts of bells and whistles to it to "tart" it up, doesn't really matter as very few GPO supplied phones are "un-Frankenphoned" like a lot of WE refurbs.

If you want any links to spares suppliers or accessories, let me know I have plenty of bookmarks.

Enjoy, I think you will enjoy the bell sound compared to your domestic stuff, as I enjoyed hearing my WE's when I ring em, I'm warning you - they are rather more shrill and loud than you might expect!
"now this should take five minutes, where's me screwdriver went now..?"

gpo706

"now this should take five minutes, where's me screwdriver went now..?"

LarryInMichigan

#3
My GPO 746 arrived today.  It seems to mostly work, but the ringer barely moves when a call arrives, though the seller included a note stating that the ringer was loud.  The shell is badly discoloured.  Below is a picture of the front of the shell with the ring removed.  It looks worse in person than the picture suggests.  Also, there is an extra 1.8uF capacitor connected to the circuit board.  On the side of the capacitor are the remains of a round piece of double-stick tape.

Larry


gpo706

Don't know what the capicitor is for, but easiest mechanical problem with the ringer could be that being are that the bells are slightly asymmetric and could have moved in transit to being too close for the clapper to move properly, slacken the screws very slightly and rotate to adjust the gap, then tighten again.

The standard wiring that works for mine are:

Strap only 5-6, 16-17-18-19

The dual-diode rectifier you have already is correctly fitted between 1 and 2, you may need a 3.3k resisitor between 4 and 5 to drop the REN to 1.

Handset to:

white - 10, red - 1, green - 2, blue - 3.

Line to;

green - 15, blue - 6, red - 8, white - 18. (on BT cord or PST)
"now this should take five minutes, where's me screwdriver went now..?"

LarryInMichigan

gpo,

The gongs are not close to the clapper.  I can only tell that the ringer is getting current by touching the clapper with my finger while it is supposed to be ringing.  The amount of movement is almost imperceptible.  I will have to investigate that issue later after working out various other issues like the discolouration of the shell.  I sure hope that I don't have to heavily sand it.  If anyone has any suggestions for a product which might bleach the shell colour back to where is should be, I'd be most appreciative.

Thank You

Larry

gpo706

http://www.samhallas.co.uk/collection/retr0bright.htm

I used the oxy-bright method on a "tanned" ivory and it worked a treat but not on a colour set.

I've never tried sanding a phone, so if you're comfortable with that might be an option.

http://www.britishtelephones.com/fault1.htm

Bell does not ring

   1. If the phone is converted then check that the resistor is installed or a metal link is in it's place.
   2. Ensure that bell fixings screws are all present and that bell mechanism is free and that the clapper arm can swing from side to side.
   3. Ensure that bell gongs are not touching the bell clapper arm.
   4. On 700 type telephones, metal swarf can sometimes be attracted to the magnet and get into the mechanism.
   5. Bell ON/OFF switch operated.

Bell faint

   1. Bell gong fixing screws are loose and gongs have rotated and closed together.
   2. Bell clapper has dropped off - replacement needed of the whole bell assembly.
   3. On 700 type telephones - paper wedged between clapper and bell gongs.

Good luck!
"now this should take five minutes, where's me screwdriver went now..?"

LarryInMichigan

gpo,

I appreciate your help.  Curiosity got the best of me, so I took a look at the ringer and solved the problem.  The clapper mechanism, which is held in position by two screws at the top of the ringer, had slid too far forward, preventing the clapper mechanism from pivoting.  I slid the mechanism back a bit and tightened the screws, which were a bit loose.  I also fitted a 3.3K resistor in series with the ringer, as you suggested, and the phone rings beautifully now.

I should be looking into the bleaching scheme, but it looks to be a bit more complicated than what I have time to do.

Larry

gpo706

Result Larry!

So did you rewire it or leave as is?

I tried the retrobright on a grey case and it left it with white blooms, but as mentioned in the article these might just polish out.

"now this should take five minutes, where's me screwdriver went now..?"

LarryInMichigan

The only rewiring I did was removing the extra capacitor and replacing the strap which was in line with the ringer with a 3.3K resistor.

Larry