GPO Planset N625, oh dear.....

twocvbloke · March 05, 2018, 06:33:05 PM

Well, been wathing this for a few days, and nobody else bid on it, and I just popped a £6 bid in on it, and won it, for the opening bid of £5.99 plus £3.49 postage, hmm...

https://www.ebay.co.uk/itm/312076287143

Why the oh dear? Well, first there's wiring a phone up to the thing, I've found the appropriate N-diagrams to follow, but, it's still a lot of wires to figure out, and there's another issue, buzzers, the planset requires them to buzz the extension(s) and main as an intercom, so I'll have to keep a look out for them or come up with an alternative solution, and of course, I need a lot of patience, oh, and two phones to dedicate to the cause...

I dunno, the things we do eh?

Owain · March 06, 2018, 05:50:18 PM

Buzzers are easy - any buzzer than can work on 10V DC can be used in the extension phones. Maplin may have some cheap right now. They also need a call button but IIRC that is only SPST. (The same seller has some switches 5A-4 for the 746 etc phones). The buzzer for the main is in the N625.

The big problem is that as well as the N625 planset base you also need an additional hookswitch contact and a capacitor:

In Telephone No. 706 an additional gravity-switch spring-set and capacitor (Adapter, Plan-Set No. 1) should be mounted on the gravity-switch bracket of the Main telephone, with the spring-set opposite the existing gravity-switch spring- set, and the capacitor behind the bracket and regulator. In Telephones No. 746 a Switch No. 19D-1, and a Capacitor No. 7712-2 with a Clip No. 90 should be fitted.

The hookswitch additional contact (or one of them) prevents the exch line being held by the planphone hold resistor when the handset is on-hook. Not sure if it has any other function in the circuit?

http://www.britishtelephones.com/plans625.htm

Still not a bad price though for the bits especially with the cord and Block Terminal.

twocvbloke · March 06, 2018, 06:25:06 PM

Quote from: Owain on March 06, 2018, 05:50:18 PMThe big problem is that as well as the N625 planset base you also need an additional hookswitch contact and a capacitor

Hence the "oh dear" as I knew I was missing something parts-wise, now I know what...

I just missed the end of that listing for the switches, but it seems they didn't sell so may be relisted, but that said I have my manual 706 that has a Press button on top, so that could be used (perfect for an intercom extension, buzz the base, be buzzed by the base, receive calls put through by the base, have the base make calls, etc.), but it could just be an excuse to get another phone, Phonitis sufferer after all...

As for Maplin, despite going the way of Radio Shack, apparently they're still charging full prices according to those who have been for a bargain, last thing I got from Maplin was my Uni-T UT30B multimeter about 4 or 5 years ago, they just were to expensive for basic hardware and electronics, it's no wonder they're going down the swanny... $:-\$

twocvbloke · March 10, 2018, 04:51:10 AM

Well, this Planset has arrived, and it's in decent shape, internally there's some slight issues with the switch piles, the rod the plastic pieces slide along is sticky and in need of cleaning and lubricating as one side of the switch pile isn't springing back to where it's meant to be, so if it was wired up, it probably wouldn't release the line when it was meant to...

Haven't gotten to taking pictures yet, seems to be one of "those" days and I'm low on energy, so they'll come later...

twocvbloke · March 10, 2018, 12:18:13 PM

Definitely one of "those" days, keep dozing off!!

Anyway, freed up the sticking switch pile, attached my green 706 (no line cable, so, perfect trial candidate, even if it's the wrong colour!), wired it in despite no additional parts to make it work properly, dug out a 10vDC power supply and added electricity, and, the thing powered up nicely, the two illuminated buttons light up when depressed and the phone is off-hook, I hear the relay clicking inside when the handset is lifted and replaced, and connecting T2 to T15 in the connection block sounds the buzzer in the base, so that works...

Still haven't taken pictures, just being lazy I guess!!!

twocvbloke · March 11, 2018, 07:14:14 AM

Pictures time at last, one thing I'll note about this planset is it doesn't seem to be GPO issue, or if it was, it's been refurbished by Ibex, who have been mentioned on the forum in the past as a maker of modernised pushbutton dial versions of the GPO 746, under where the "IBEX/3" sticker is there's what appears to be a smear of black paint that may have erased a previous date/maker code, and due to the texture of the paint, I can't make out what it could be... $:-\$

Anyway, pictures, merged them into a mosaic, just to save posting all of the individual pictures over several posts...

twocvbloke · March 11, 2018, 07:47:20 AM

And in typical dodgy TV advert fashion, "But wait, there's more!!!":

https://www.youtube.com/watch?v=Wc6NRb5Ctmw

Had a play with the buzzer circuit and the lighted buttons before taking the thing apart for the pictures, so made a couple quick mobile phone clips of it, which turned out a bit terrible as my mobile seemed to mute the audio making the buzzer sound like it fades in...

Owain · March 11, 2018, 07:54:06 AM

:-)

Owain · March 13, 2018, 05:35:21 PM

Quote from: twocvbloke on March 06, 2018, 06:25:06 PMI just missed the end of that listing for the switches, but it seems they didn't sell so may be relisted

Yup. https://www.ebay.co.uk/itm/5-X-SWITCH-5A-4-FOR-746-TELEPHONES/312086292790

Sir will also require the buttons and the little locking pins for them.

twocvbloke · March 14, 2018, 02:53:31 AM

Buttons shouldn't be too much of an issue to find, the pins might be though, but we'll see...

Owain · March 14, 2018, 04:34:29 AM

Pins can probably be cut down from panel pins of appropriate diameter.

twocvbloke · March 14, 2018, 07:40:29 AM

Probably from copper T&E wire too, got plenty of that funny coloured european harmonised standard stuff around...

twocvbloke · March 15, 2018, 05:15:35 AM

Ordered a set of blank buttons for a 746 last night, £1 for a set of three (+£1.25 P&P), used but hopefully good (even if they're not, a bit of Peek metal polish would bring them back up, works nicely on clear plastic!), just need some switches next...

https://www.ebay.co.uk/itm/192410785745

Listing's still active, so I guess they have plenty for sale...

twocvbloke · March 19, 2018, 03:25:28 PM

Got a little 12v buzzer off ebay for £1.97 (99p for the buzzer, 98p for the postage), and just tried it out in my chocolate brown 740 (which was converted to a 746, so no 740 guts left sadly), and the thing sounds hilarious, at 400Hz, the buzzer sounds like the phone has a little car horn inside it, if I ever manage to get a Direct Line phone, I'll fit one of these buzzers inside it just for novelty purposes!!!

https://www.ebay.co.uk/itm/202260931516

Picture of it temporarily mounted inside the phone plus the ebay listing:

twocvbloke · March 19, 2018, 07:43:12 PM

Didn't win that set of 5x switches & Zebedees, darn...

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GPO Planset N625, oh dear.....