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GPO handset no. 17A - Neon lamp & Amplifier handset!!

Started by twocvbloke, May 19, 2013, 03:30:58 PM

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twocvbloke

And the best bit, it's from Bob Freshwater himself, the owner of http://www.britishtelephones.com, only noticed that after I paid... ;D

http://www.ebay.co.uk/itm/330922316507

Although he listed it as the No. 14 (Amplified only), it's definitely a 17A (I mentioned it to him when asking if he was indeed mr. Freshwater), so it has both the neon lamp which illuminates when the line rings, and an amplifier for use in noisy situations or by the hard of hearing... :)

Now I need to do two things, read up on how it's connected up, and find a two-tone grey phone (aside from my Mk.28!!) to match it... ;D

Owain

From Bob Freshwater! OMG that is almost as good as something with A G Bell's thumbprints all over it.

twocvbloke

Yep, the one and only (well, I'm sure there are others out there, but this one has the best resource for GPO stuff), and thanks to his website, I've used that other super resource run by Sam Hallas to find the right N-diagram to wire up the handset properly:

http://tinyurl.com/N1843 - (That tinyURL Custom Alias thing is handy, cos N1843 is the diagram number!! :D )

Looks like I need to find me a 15K resistor, and for some reason, that makes me think I have some (I know I bought some 20Ks recently for that duff UPS), but knowing my luck, I won't... :D

Seems he was selling off a few bits and pieces, looking at his Completed Listings, of course, all the GPO stuff sold, the only thing that didn't was a trailer hookup connection thing:

http://tinyurl.com/lcwfn7z

gpo706

You shouldn't have any problems I put one these on one of my greys.
"now this should take five minutes, where's me screwdriver went now..?"

twocvbloke

Quote from: gpo706 on May 20, 2013, 04:45:57 PM
You shouldn't have any problems I put one these on one of my greys.

I'm just a niggly sort, the GPO specified that it needed the 15K resistor, presumably to limit the current being sent through the neon lamp/ringer so that it was equally balanced, and that the neon lamp has a longer service life, so I'd rather fit one, just to keep it accurate to the specs... :)

Seems I don't have any 15K resistors though, so, I shall have to acquire some!! :D

Owain

5 x 3k in series ...

You have 3k resistors, of course.

twocvbloke

Quote from: Owain on May 21, 2013, 05:01:31 AM
5 x 3k in series ...

You have 3k resistors, of course.

That I do, well, 3.3K resistors, but who's counting... :D

Thing is, I already bought a set of 15K resistors, I couldn't help myself, I just had to do it, after all ......

twocvbloke

Well, the resistors are here, just waiting for the postie to bring the handset so I can wire it up to a phone to try it out... :D

twocvbloke

And it's here!!!  ;D

Haven't tried wiring it up to anything yet, I'm barely awake as it is, so I'll play with it later on today when I've slept... :D

Still need to snap a pic of it though, but again, I'll do that later... :D

twocvbloke

And finally, it's been photographed, fitted to my green 746 with ringer control, and tested on the 616... ;D

And a video of it here too:

https://www.youtube.com/watch?v=gUaowMnLUP4

It's weird seeing the neon lamp flashing at 20-25Hz (not sure which the 616 puts out), I'm used to seeing neons on 50Hz which is a lot faster in comparison, in this one I can see the bars inside the lamp flashing alternately, kind of like a back & forth strobe effect... :D

Probably not good for those with epilepsy though... :o