Kitz Forum
Chat => Tech Chat => Topic started by: burakkucat on September 22, 2016, 10:40:05 PM
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I was just doing a sweep of eBay, to see what sort of prices are being asked for the new NTE5/C & the NTE5/C plus Mk 4 filtered faceplate, when I came across an item (http://www.ebay.co.uk/itm/222208249519) advertised as --
Genuine Phone Master Socket NTE5a +Back Box +IDC Tool. COMMMTEL for BT Openreach
-- with a sub-heading of --
MADE IN THE UK FOR BT BY RATHDOWN INDUSTRIES LTD.
Looking at the images it most certainly is not an "NTE5a", nor is a "Back Box +IDC Tool" visible.
It appears to have the standard BT 631A socket under a shutter on the front and the equivalent plug on the back. It looks as if there is a red LED at the top right of the bevelled edge and the unit is designed to plug into either an NTE5/A or a LJU . . . I haven't attempted to deduce the size of the device by measuring the height & width of the 631A plug visible in the image and then scaling appropriately, so I can't be sure if it would fit onto an NTE5/A or one of the earlier LJUs. Also note how it unclips to allow four AA size cells to be fitted. Very mysterious.
Does anyone recognise such a unit, please? :)
[One other totally irrelevant fact . . . The vendor's address is just a short distance away from where I used to live in the early 1970s.]
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Just a wild guess, but coming at it from the angle of what purpose could be served by such a device, how about a 'fault indicator' should the exchange line go open-circuit?
To display the fault light, the AA cells would be called upon. Such a device might be useful in, for example, a monitored alarm system, to warn that the prospective burglars had snipped the phone lines. Might it also have a built in beeper not shown in the photos?
Just my own train of though, probably about to be proven wrong... :D
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Two comments...
- That approval sticker is pretty old, isn't it? Those green circles died out a long time ago ... didn't they? The approval number didn't lead to any more clues though.
- It mentions a REN of 1. That suggests something that consumes some of the ringing energy from the line. Yet it also needs batteries. Confusing
My guess is some form of ringer, augmented by a flashing light. But that wouldn't need batteries ... so it isn't a very good guess.
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I'd guess at it being a ringer of some sort, Commtel still make such devices or did until recently.
Odd that the BT plug doesn't have a latch and release mechanism though.
That black plastic key object doesn't look to belong to it either.
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Rathdown Industries also appeared to go bust in 2001/2002. Its not a new item!
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- That approval sticker is pretty old, isn't it? Those green circles died out a long time ago ... didn't they? The approval number didn't lead to any more clues though.
The labels, with either a big green circle (indicating approval) or a big red triangle (indicating disapproval (if I am remembering correctly)), ceased to be relevant when the BABT was abolished, many years ago.
I also tried to read the BS number shown on the front of the device and then search for the relevant British Standard. Depending upon how I read it, I was vectored to documents relating to drainage! ???
- It mentions a REN of 1. That suggests something that consumes some of the ringing energy from the line.
My understanding may be somewhat askew but surely it is not correct to say that a device which has a REN number assigned to it actually consumes some of the "ringing" energy. My overall understanding of the REN concept is that it is a simple numerical approximation of the overall loading that the device presents to the circuit.
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Odd that the BT plug doesn't have a latch and release mechanism though.
That black plastic key object doesn't look to belong to it either.
Yes, I agree with both of your observations.
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The labels, with either a big green circle (indicating approval) or a big red triangle (indicating disapproval (if I am remembering correctly)), ceased to be relevant when the BABT was abolished, many years ago.
I also tried to read the BS number shown on the front of the device and then search for the relevant British Standard. Depending upon how I read it, I was vectored to documents relating to drainage! ???
The LED comes on when your drains are blocked!!!! :lol:
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The LED comes on when your drains are blocked!!!! :lol:
b*cat gives a black look in a certain direction. :P
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One other observation that I have failed, so far, to mention (and that no one else has yet commented upon) is what looks like a button that protrudes from the top of the device.
I was hoping that perhaps one of our ex-GPO/POTel/BT members might have come across such a doings in the dim and distant past. In terms of date, I put it as post 1981 but pre 21st century.
Perhaps the simplest solution would be somebody local to go to the address and purchase one! :D
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The button on top could be a linkage to a latch lever that has broken off. In that case, it might have broken off when the device was removed by an individual who hadn't figured out what the button was for.
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Sorry, phones were still hard wired the last time I was involved with them. :)
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Odd that the BT plug doesn't have a latch and release mechanism though.
I think it's the same as why the BT plug on the back of any modern filtered faceplate or lower front part of the NTE5a doesn't have a latch. ;)
I thought the thing on the top is just to hold a screw.
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I also tried to read the BS number shown on the front of the device and then search for the relevant British Standard. Depending upon how I read it, I was vectored to documents relating to drainage! ???
My second guess found that too. My third guess was for BS6301, which defines the safety requirements for connection to the phone network ... whereas BS6305 seems to be the more usual "general" set of requirements, and may be quoted more often. I stopped looking after that.
My understanding may be somewhat askew but surely it is not correct to say that a device which has a REN number assigned to it actually consumes some of the "ringing" energy. My overall understanding of the REN concept is that it is a simple numerical approximation of the overall loading that the device presents to the circuit.
My understanding was that the electrical power on the line was enough to be detected by devices, provided a total REN was no more than 4. Above that, devices weren't guaranteed to be able to ring properly.
In the days of real bells, I took that to mean that the share of the power would then not be enough to energise the ringer's solenoid.
(Too many loads + fixed power input) => share of power drops below threshold => ringing not detected
So the REN does indeed represent an approximation of "loading" - but the ultimate consequence comes from the consumption of energy that is the natural effect of adding more loads.
(However ... the length of the line plays a significant part in the "load" too, so I guess a REN of 4 mostly applies to the longest line, which places the biggest restriction on energy available to devices. Shorter lines can presumably cope with higher REN values).
In terms of a generic circuit, I always thought the load was indeed something the consumed electrical power, and that we could equate that with consumption of electrical energy. Wiki (https://en.wikipedia.org/wiki/Electrical_load) agrees in part, but perhaps you see it differently.
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Re: REN's
I have tried this many many years ago with multiple devices such than the combined total REN was 5 on a medium long length line.
Sure enough the phone line then had "ringing problems". As I dimly recall the real effect was that some of the phone units 'sort of rang' and others did not.
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I was just doing a sweep of eBay, to see what sort of prices are being asked for the new NTE5/C & the NTE5/C plus Mk 4 filtered faceplate, when I came across an item (http://www.ebay.co.uk/itm/222208249519) advertised as --
Genuine Phone Master Socket NTE5a +Back Box +IDC Tool. COMMMTEL for BT Openreach
-- with a sub-heading of --
MADE IN THE UK FOR BT BY RATHDOWN INDUSTRIES LTD.
Looking at the images it most certainly is not an "NTE5a", nor is a "Back Box +IDC Tool" visible.
It appears to have the standard BT 631A socket under a shutter on the front and the equivalent plug on the back. It looks as if there is a red LED at the top right of the bevelled edge and the unit is designed to plug into either an NTE5/A or a LJU . . . I haven't attempted to deduce the size of the device by measuring the height & width of the 631A plug visible in the image and then scaling appropriately, so I can't be sure if it would fit onto an NTE5/A or one of the earlier LJUs. Also note how it unclips to allow four AA size cells to be fitted. Very mysterious.
Does anyone recognise such a unit, please? :)
[One other totally irrelevant fact . . . The vendor's address is just a short distance away from where I used to live in the early 1970s.]
It is a 'Phoneguard-P' - a device that locked over the phone socket and used for blocking various outgoing calls. I have one sat in from of me here.
Ian
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It is a 'Phoneguard-P' - a device that locked over the phone socket and used for blocking various outgoing calls.
Thank you. Mystery solved. :)