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British Ericsson or Plessey N1905 (GPO 710 copy)

Started by gpo706, August 05, 2010, 03:50:24 PM

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gpo706

It was £1.04 plus £7 shipping.

So what the hell have I bought now, another boring two-tone grey?

Well its a British Ericsson or Plessey "plan set" N1906, although the seller says its an N1905.

"Plan-Etelphone" system.

So it's a GPO 710 planset copy:

http://www.britishtelephones.com/t710.htm

with one blank and 3 buttons - they read:

ABST/EXT/ANS FILTER

On the base it has - N1905E13T.

http://www.britishtelephones.com/ericsson/n1906.htm

Golly - another rewire job!

What I found interesting was the silvered chevroned backplate,and the numbered grey dial surround - never seen this combination on a standard GPO set, so obviously a BE/Plessey made items.

It would work nice with a "Conquest" handset:

http://www.britishtelephones.com/hands17.htm

How to ID:

http://www.britishtelephones.com/ident1.htm

"British Ericsson (ETEL)
This company normally prefixed it's part numbers with an N.  So on the base expect to see something link N1016.  The part number may be extended i.e. N1016A16, but it's base number is N1016 and the variant of this would be A16.  Inside may be a diagram and these are numbered and they start with N as well.  These diagram numbers DO NOT represent the model or part number and are the diagram number only.  In the Ericsson telephone list you will find that some diagram numbers can be cross referenced."

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

gpo706

#1
Okay-doaky, this arrived same day as my 250.

The 250 got "the treatment" first and works lovely.

Had no linecord, again as chance will have it, the brand new replacement linecord arrived same day, so I had all the bits, so an incentive to get get of my arse and do the business.

First impressions - its pretty tidy, no cracks, a slight scuff one side, but practically looks used but not unseemly.

The 3 buttons all depress and recoil fine, they are from L-R - "ABS'T" (absent?), "EXTN", "ANS FILTER". The "Absent" button locks down with a littlle slide on the top. The 4th aperture has a neat (matching) dark grey blanking insert.

Now I open it up, there's a bunch of circuits, capicitors and weird wiring all over thie set, all they were all disconnected - the wires being just cut right off.

So on a 706 (which this is based on) you have two rows of screw connectors at the rear, 1 to 9 and 10 to 19.

So I thought - sod it will try a basic rewire with the new line cord, so you strip everything out and rewire as such:

http://www.britishtelephones.com/pstconv1.htm#700

Plug it in - and....

Faint dial tone.

Right - try a test on the CO line, - fine but still low RX volume, take the earpiece off and theres a horrible plasticy looking BE/Plessey made thing in in, so replace that with a spare from a scrapped 706, and its much better.

Next a PBX test - phones Mother downstairs who is much annoyed as she's watching some crap film, anyhow she says I'm quite faint.

So out with the TX and another replacement.

Fearing the wrath of mater, I call my brother's extension (yeah, yeah, I'm that sick I forced an extension into his room from the PBX).

He says its sounds fine, so I force him into my room and dial my room to hear what he's hearing - its all good.

Now I try a ring test through the PBX - nothing.

So it works, but no ring, either the amazingly weird wiring I stripped has isolated the ringer or its kaput and will need replaced, I suspect the former.

Anyway I gave it a good wipe over with antibacterial cleaner and it came up quite nice, I'm past the stage of doing a full wash of everything on a decent looking phone because I have had some mishaps, like brittle plastic bits shattering when put under force etc.

"If it isn't broke, don't fix it..."

Couple of notes - it came with a green pickup handle, these are rare enough, so I took it off and put 2 standard chrome spares I had on it.

These pickup bars are so under-engineered and flimsy, I had a matching grey on one of my 706's and it snapped off when I lifted it one day - absolute rubbishy last minute design modification - you can get chrome bars which are the best solution.

Also the dial plate with the chevrons is actually a 3-D engraved filled with black paint, its amazing when you look at it from different angles as they catch the light, really stunning bit of detail the GPO never used.

Lastly I'm fed up with clear dial fingerwheels, so I took the absolutely perfect wheel off and swapped it for a grey off a finished 706, it looks the business, its a nice colour match for the case.

Anyway I'll get back to you when I figure out why it won't ring...

S.







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

McHeath

My 706 has the chrome pickup bar which is a sweet touch.

I really like the 706 with a solid color fingerwheel that matches the case.  Those built in buttons that either have a blank or functioning button are mysterious to me, nothing like that on our 500s of the era.  This is a nice looking phone you have found, surely the ringer problem is simply a wiring issue.

gpo706

#3
McHeath - one of the joys is these "non-standard" sets with buttons and lights etc put Joe Punter off, as like us he doesn't have a clue what they are on it for, and they go cheap as chips, also when the ad says - no line cord.

Thats pretty daunting for your average buyer, unlike schmucks like us who assure themselves they can convert them to work!

I guess modular line cords wouldn't be so much of a problem for US punters, but the thought of having to open it us and start unscrewing stuff is too much.

The chrome finger bar is the most practical solution for the wafer thin plastic ones, plus it looks really pretty, you could go the whole hog and get yourself a chrome fingerdial for it, if you could bear not having the colour-matched set!

I've personally found my 3 500s and my 554 the easiest sets I've dealt with regarding conversion, even if I had to get stuff like new jack sockets all the way from Phoneco because the originals were brittle and broke easily.
"now this should take five minutes, where's me screwdriver went now..?"

gpo706

#4
I've been wrestling with this for the last 2 days, firstly the bell connection to terminal 16 has two other green wires attached, so they were snipped, still doesn't ring...

Then croc clips the ringer up to a linesmans phone, eventually the clapper goes, so the ringer is fine, rewires it all, plugs it in and - no ring through the PBX.

So I suspect some of the additional gubbins is shorting or overriding the clapper.

It certainly isn't the clapper as it works on a straight 2 wire connection powered by a 3V linesmans set.

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

gpo706

#5
Ah HAHAHAHAHA!

Switched blue line cord in from T6 to T4 and now it rings.

This was after a few hours of combinations, from strapping T4 to T5, removing the resistor etc.

Then I thought - wire the darn in (blue) to the ringer - SHAZAMM!

Then rewired as per usual and even the dial tone is louder, a few of my 706 sets have low dial tone so I suspect a bulk rewire coming soon.

Now if you press the "EXTN" button it disconnects the line, so something is still connected inside this machine, so full of wiring its like a mini Colossus.

http://en.wikipedia.org/wiki/Colossus_computer

Well maybe not, but theres enough wires and bits stuffed inside a 706 body for me to cope with.

Next put it together and dial a test number - perfect, BUT the dial is rather slowish, but it works, so I'm going to try some cleaning of the governer in the dial and see if that helps, if not out with the dial and replace it.

"I love it when a plan comes together" though how I got it work is beyond my schematics, or brain.

I've left all the other additional bits inside (apart from some piece actually mounted on the cord grommet gate at the back) as they dont interfere anymore and had all been disconnected when I got it anyway.

Need to get a pic of the insides to show you what I've been up against, its like "Alien autopsy".
"now this should take five minutes, where's me screwdriver went now..?"

gpo706

#6
Been getting more treatment again folks.

(The phone, not me).

I got one of these off the bay:

http://www.britishtelephones.com/hands7.htm

Wired it up conventionally, and the handset works, but what of the two extra black and orange wires to power the neon light?

Well had to take apart my two-tone grey 746 with the "Conquest" handset.

http://www.britishtelephones.com/hands17.htm

(What an important name "CONQUEST" - its a handset with a light and a volume amplifier).

So this was opened up to see where it all goes as I had lost the diagram, so side by side attached the black and orange to the terminals and...

it flickers slightly.

But I have a 3.3k resistor on this set which lowers the REN to 1, so out that comes, and it flashes like a pinball machine, obviously the resistor was impeding the current to the lamp.

(They are both on the Pana 616 so doesn't matter about the resistor, as the Pana puts out 4 REN per extension).

Now to de-wire it all and clean it up, with antibacterial wipes etc, this was the most tedious and time consuming part, you do the handset, the cord, which I had previously straightened after a wipe down and clean was now in knots and the grommets - the filthiest part of any cord as you may know.

So now it all looks good and fairly shiny, untangle the curly cord, rewire, test and put the case on and finally finished.

Looks absolutely superb, thats two neon discharge handsets on greys I have now, well satisfied with my 4 hours of pleasing graft on my day off.

Next I'm going to try to adapt the one locking button on the set ("ABS'T") to disconnest the lamp when I don't want it to flash, this is the only locking button on it.
"now this should take five minutes, where's me screwdriver went now..?"

mienaichizu

Is this phone available in touch tone? I think I saw one that is similar to yours but a touch tone, here in the Philippines

gpo706

The nearest I can find is a 758 model, which had up to 4 buttons on the top and push buttons, based on a 746 though, not a 706.
"now this should take five minutes, where's me screwdriver went now..?"