Digital switchover causes TV problems in Oxfordshire

tony sayer wrote:
In article , Terry Casey
scribeth thus
tony sayer wrote:
In article
s.com, scribeth thus
On Feb 22, 10:55 pm, charles wrote:
In article ,
Martin wrote:

We have three phases. Dutch wiring is peculiar. No ring mains and the bog
standard set up limits you to a total of 16 amps. To use any sort of
electric oven you have to convert to three phase.
Ring main is a peculiarly UK system. It was invented to save on copper for
the post-war housebulding boom. Its major disadvantage is that plugs need
to be large enough to incoporate a fuse.

--
From KT24

Using a RISC OS computer running v5.16
But those postwar houses often had 15A sockets, and 15A plugs don't
have fuses.

Bill
Now I'd hate to disagree with the fount of all wisdom of Yorkshire but
ISTR there was one that had the live pin as a fuse.. but they were very
rare...
I'm afraid that you're wrong - and the fount of all wisdom of Yorkshire
is (W)right!

The device to which you refer was a THIRTEEN amp RING MAIN connector
manufactured by Dorman & Smith. (I'm sure it's been discussed on here in
the past year.)

Well these were in my old grannies house sometime back in the mid 50's,
and installed sometime in the late 20's to early 30's, and they were
round pin devices. ISTR that she only had a couple of sockets as it was
considered as the "electric light" as that's what they had this
"electrickery" as she termed it for;!..

Whether the current rating was 5, 15, or 13 amps I don't remember, but I
don't recall 13 amps ever being mentioned but it was a long time ago
now..

Having grown up in a post war council gaff, built in 1948, that did
indeed have modern day 13 amp ring main outlets no round pin devices
there!.


Thurrock Council used standard 13A sockets in all their council estates
but we also had LCC overspill estates locally as well - and they all
used the D&S type.

FWIW There were quite a lot of round pin installations in Cambridge town
up until the 70's when some parts of Cambridge still had DC yes direct
current power and at 200 volts, as we had to modify telly's to work on
that!. It was phased out when the old generating station at Thompson's
lane was closed. One of the original; dynamo's there is now in the
science museum!.


I don't know when it was changed, but Ilford had 200V DC supplies quite
late on, a hangover from when local councils generated electricity and
Ilford decided that, as they were generating 600V DC for their trams,
the domestic supply would be DC as well!

--

Terry

On Wed, 24 Feb 2010 09:16:11 +0000 (GMT), charles
wrote:

In article ,
tony sayer wrote:

FWIW There were quite a lot of round pin installations in Cambridge town
up until the 70's when some parts of Cambridge still had DC yes direct
current power and at 200 volts,

I remember 200v in Cambridge (1959-62) but it was ac. I remember having to
get a 200v element for my soldering iron since my 240 never got hot. I
kept it for years afterwards. Jesus College, at the time, had a 50v
internal distribution. I was in Reeces once and someone came in for a 150w
bulb to fit in his table lamp - the cost was enormous.
In my fathers shed there is a crate of lamps about 70 years old.
Bought them just after the war when he and 2 mates were deciding how
to earn a living. In the end it was one of the others who became the
qualified sparky* but the lamps stayed behind. 12, 24, 50 and 100
volts but all normal size and SBC. This reflected that the area had
no mains then but a fair no of small generating sets.
There are only coloured bulbs left in the crate now. I used all the
other ones up sabotaging school lighting circuits. A 24V was more than
capable of taking out the fuse and remaining intact. With an 0 drawn
on with a chinagraph pencil the rogue lamp took ages for the caretaker
to find.

*This was possibly a retrograde move as the rural electrification
programme virtually guaranteed a lifetime of profitable work,however
Dad could not sell the small farm while his elderly father was still
alive so became a builder instead as he could fit than in around farm
work. The 3rd one built up a garage and car repair business.
Interstingly may be Dad was right, he still has the smallholding and
renting the field out supplements the pension,
My brother became the builder. However the garage has gone unable to
make a profit on fuel and modern vehicles being too reliable and
requiring expensive diagnostic kit. The electricians Son became an
electrician but could not keep the business. The replacements for the
Bush tellies and Hotpoint Twin tubs his Dad supplied came from Sony
and Beko via Comet etc.
Fortunately his two mates passed on before they saw their life's work
finally wither.

G.Harman

charles wrote:
In article ,
tony sayer wrote:

FWIW There were quite a lot of round pin installations in Cambridge town
up until the 70's when some parts of Cambridge still had DC yes direct
current power and at 200 volts, as we had to modify telly's to work on
that!. It was phased out when the old generating station at Thompson's
lane was closed. One of the original; dynamo's there is now in the
science museum!.

I remember 200v in Cambridge (1959-62) but it was ac. I remember having to
get a 200v element for my soldering iron since my 240 never got hot. I
kept it for years afterwards. Jesus College, at the time, had a 50v
internal distribution. I was in Reeces once and someone came in for a 150w
bulb to fit in his table lamp - the cost was enormous. the ADC theatre had
an Electricity Board provided transformer to get its mains up to 240v since
the lighting control board dropped about 12% of the voltage; with the
transfomer we'd have had 175v on the lamps, even if they were 200v ones.
It meant that we could swap kit with the Arts.


The first BBC studio I entered was The Playhouse Theatre, in 1965, with
a local pop group. No point naming them, as you'll never have heard of
them but the top of the bill that day (it was a recording of "Easybeat")
was a young Welsh miner, lad by the name of Jones ...

During the rehearsal, I was presented with a broken guitar lead, so I
sat on the corner of the stage and repaired it - at least, I tried to!

When I came to solder the damn thing, I couldn't make the solder melt!
The iron was obviously hot but not hot enough!

Eventually I put my trusty multimeter across the mains - and read a mere
197 volts!

My iron did eventually get hot enough to finish the job but I was glad
it wasn't urgent!

I was not surprised when I heard a few weeks later that The Playhouse
was being closed for 18 months for a re-fit!

By the way, as I'm sure there will be a few readers who would have known
The Playhouse in mid 60s, does anyone know who won the raffle?

(If you ever had a cup of tea there, I'm sure you'll know what I'm
talking about!)

--

Terry

dswan wrote:
On 23 Feb, 18:26, charles wrote:
In article
,
wrote:

On Feb 23, 2:05 pm, dswan wrote:
Ah but they were always available, and still are (cost a bomb though):
http://www.neweysonline.co.uk/mk-ele...g-three-pin-fu....
I always wondered why they didn't make much more extensive use of
those.- Hide quoted text -
- Show quoted text -
Ten quid?
If you must have a real MK it will cost that - I can get unbranded ones at
TLC for about £1; Duraplug "rubber" ones cost about £4.30 - Permaplug ones
about £2 less

--
From KT24

Using a RISC OS computer running v5.16

Yes, but are those the fused ones you're talking about? Thats the
point I was making - that, contrary to what most think, it was always
possible to get fused BS546 plugs. The one in the picture is over £10
as its a fused one - I assume the reason it costs so much is that
there's practically no demand for them and therefore economies of
scale don't apply.

However, thats what I was trying to say (not very clearly) - rather
thandevelop a completely new system, I'm surprised BS 546 as an extant
system didn't simply get modified to use fused plugs such as the one
shown.

Could that be that there would have been millions of un-fused plugs
already in use - which would have been plugged into the new ring mains,
thus defeating the object?

--

Terry

Ivan wrote:


"dswan" wrote in message
...

However, thats what I was trying to say (not very clearly) - rather
thandevelop a completely new system, I'm surprised BS 546 as an extant
system didn't simply get modified to use fused plugs such as the one
shown.

I stand to be corrected because it might well be an old wives' tale, but
AIUI it was all to do with austerity, flat pins dissipated more heat and
used less metal than round ones.

Have you ever looked inside a 13A socket and seen:

a) How thin the metal is that the female contacts are made from?
b) How small the contact area between male and female is?

--

Terry

On Wed, 24 Feb 2010 08:02:14 -0000, "Doctor D"
wrote:


" wrote in message
...
On Feb 23, 3:30 pm, Peter Duncanson wrote:
On Tue, 23 Feb 2010 13:20:36 +0000, Terry Casey
wrote:
My memories might have been contaminated by a recent experience. I
bought a surface mounting box for a light switch. I attempted to remove
one of the knock-out sections to make a cable entry point. There was a
sharp breaking sound and I was the proud owner of a box in two pieces.
The whole of a corner had broken off. The knock-out section was still in
place.

--
Peter Duncanson

We often mount TV/SAT plates on patresses, and breakages are common,
even when you're used to doing it. I've found that Contactum ones are
as good as any.

Bill


I never go to a job with less than 3 of these, even when only one will be
required.
If they don't crack when knocking out the entries, they sometimes do when
tightening the faceplate! Maybe I'm ham-fisted.

I don't notice a huge difference in brands, haven't tried Contactum.
Crabtree are good but not cheap.

I don't do this professionally, just for my own use at home - TV,
phones, LAN/internet, mains. This is only the second patress that has
broken in many years. I take full responsibility for breaking the first
one. The second one broke of its own free will!

--
Peter Duncanson
(in uk.tech.digital-tv)

On Wed, 24 Feb 2010 10:19:29 +0000, Terry Casey
wrote:


Ring main is a peculiarly UK system. It was invented to save on copper for
the post-war housebulding boom. Its major disadvantage is that plugs need
to be large enough to incoporate a fuse.

--

FWIW There were quite a lot of round pin installations in Cambridge town
up until the 70's when some parts of Cambridge still had DC yes direct
current power and at 200 volts, as we had to modify telly's to work on
that!. It was phased out when the old generating station at Thompson's
lane was closed. One of the original; dynamo's there is now in the
science museum!.


I don't know when it was changed, but Ilford had 200V DC supplies quite
late on, a hangover from when local councils generated electricity and
Ilford decided that, as they were generating 600V DC for their trams,
the domestic supply would be DC as well!

Exeter had a pocket of DC down by the Canal Basin until the 70's . Can
remember the conversion being announced on the news. Bournemouth had
some surprisingly late. In a book I have on the History of Southern
Electric it mentions that in 1971 there were 1656 customers on a non
std supply all in the Bournmouth area. by 1972 the voltages had been
adjusted to std but DC hung on until 1978 when the last two customers
were converted.

G.Harman

On 24 Feb, 10:13, Terry Casey wrote:
wrote:
On 23 Feb, *
* * *Adrian wrote:

charles wrote:
In article , Terry Casey
wrote:

The device to which you refer was a THIRTEEN amp RING MAIN connector
manufactured by Dorman & Smith. (I'm sure it's been discussed on here in
the past year.)
They were widely used on post-war council housing estates and the
suspicion is that D&S offered the sockets to local authorities at a much
lower price than the convention MK, Crabtree, etc., 13A type, knowing
that they'd recoup any loss from the ridiculously over priced (patented)
plugs and fuses that the householders would be forced to buy afterwards.

There were at least 3 contenders for the "ring main plug". NSHEB used yet
another one. *In the end the MK version won, but I suspect the bulk of
the D&S installations happened before the current standard was agreed on

Do you remember the Wylex contender? They hung on for quite some time in
places.

At a technical college I worked at they had all three, and also 5 and 15A
sockets. I spent lots of time making and repairing adaptors so that equipment
could be moved between labs.

The most ingenious adaptor I've ever seen was shown to me by a puppeteer
many years ago. As he performed in a very wide range of places, he had
to be prepared for anything!

The main part consisted of two rectangular brown pieces of bakelite with
a pin protruding from one face close to the end. The pin were small
enough to fit a 2A socket and were used for live and neutral.

They were fitted into some kind of spring loaded bracket which forced
the pins apart. By squeezing them together, he could match the hole
spacing of any size socket. Where he came by it I do not know - I think
the sprung bracket may have been his own idea.

This device was used in conjunction with a separate multi-pin earth
which he'd made by welding together earth pins removed from 2, 5, 13 &
15A plugs 90 degrees apart from each other - he probably had Wilex and
D&S earth pins on there as well, but I can't remember.

With this contraption, he could match any 2 or 3 pin socket he encountered!

Did he make it himself? It sounds like a Fitall plug.
http://vads.ahds.ac.uk/diad/bres/pub...95/065gray.jpg (centre
right)

On 24 Feb, 10:51, Terry Casey wrote:
dswan wrote:
On 23 Feb, 18:26, charles wrote:
In article
,
* wrote:

On Feb 23, 2:05 pm, dswan wrote:
Ah but they were always available, and still are (cost a bomb though):
http://www.neweysonline.co.uk/mk-ele...g-three-pin-fu.....
I always wondered why they didn't make much more extensive use of
those.- Hide quoted text -
- Show quoted text -
Ten quid?
If you must have a real MK it will cost that - I can get unbranded ones at
TLC for about 1; Duraplug "rubber" ones cost about 4.30 - Permaplug ones
about 2 less

--
From KT24

Using a RISC OS computer running v5.16

Yes, but are those the fused ones you're talking about? Thats the
point I was making - that, contrary to what most think, it was always
possible to get fused BS546 plugs. The one in the picture is over 10
as its a fused one - I assume the reason it costs so much is that
there's practically no demand for them and therefore economies of
scale don't apply.

However, thats what I was trying to say (not very clearly) - rather
thandevelop a completely new system, I'm surprised BS 546 as an extant
system didn't simply get modified to use fused plugs such as the one
shown.

Could that be that there would have been millions of un-fused plugs
already in use - which would have been plugged into the new ring mains,
thus defeating the object?

--

Terry

Very true.

Since my last post I've looked at the IEE docs someone put up earlier
in the thread regarding the discussions around the development of the
ring circuit in the early 1940s, and it gives chapter and verse on
this whole issue - very interesting reading.

"dswan" wrote in message
...

On 24 Feb, 10:13, Terry Casey wrote:
The most ingenious adaptor I've ever seen was shown to me by a puppeteer
many years ago. As he performed in a very wide range of places, he had
to be prepared for anything!

The main part consisted of two rectangular brown pieces of bakelite with
a pin protruding from one face close to the end. The pin were small
enough to fit a 2A socket and were used for live and neutral.

They were fitted into some kind of spring loaded bracket which forced
the pins apart. By squeezing them together, he could match the hole
spacing of any size socket. Where he came by it I do not know - I think
the sprung bracket may have been his own idea.

This device was used in conjunction with a separate multi-pin earth
which he'd made by welding together earth pins removed from 2, 5, 13 &
15A plugs 90 degrees apart from each other - he probably had Wilex and
D&S earth pins on there as well, but I can't remember.

With this contraption, he could match any 2 or 3 pin socket he
encountered!

Did he make it himself? It sounds like a Fitall plug.

http://vads.ahds.ac.uk/diad/bres/pub/COID/195/065gray.jpg (centre right).



An absolute bargain at only 12 shillings and sixpence, have they got a web
address where I can order one?o)