Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became useless as the telephone got changed to 5ps and 10ps. (This was of course the telephone box down the road -- we didn't have one in the house.)

And being told to put the radio on at 5 to 1 for the 1 o'clock news - it needed time to 'warm up'.

Owain

I have a Rogers Amp on my computer like that. Four ecl 86s need a bit of
time to get their acts together.


Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
wrote in message
...
On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became useless as
the telephone got changed to 5ps and 10ps. (This was of course the
telephone box down the road -- we didn't have one in the house.)

And being told to put the radio on at 5 to 1 for the 1 o'clock news - it
needed time to 'warm up'.

Owain

In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)
--
Graeme

Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.

--
Chris Green
·

On 22/06/2017 09:46, Chris Green wrote:
Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.

Internet and DAB both take an age to get going. The big advantage of the
simple AM/FM transistor radio is that it runs a long time on batteries.

--
Regards,
Martin Brown

"Martin Brown" wrote in message
news
On 22/06/2017 09:46, Chris Green wrote:
Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.

Internet and DAB both take an age to get going. The big advantage of the
simple AM/FM transistor radio is that it runs a long time on batteries.

as the advert SHOULD say.... if you love radio don't buy a DAB .......

On 22/06/2017 09:46, Chris Green wrote:
Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.

Mains valve radios were up and running in 20 seconds.

A lot of modern equipment takes a lot longer than that. Apart from
(obvious) computers, TVs and mobile phones have quite restricted
functionality, or are very slow to respond, until a lot of background
tasks have finished running.

--
Max Demian

On Thu, 22 Jun 2017 18:56:20 +0100, Max Demian wrote:

On 22/06/2017 09:46, Chris Green wrote:
Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.

Mains valve radios were up and running in 20 seconds.

Battery ones were even faster. Typically using the D?9? valves, they had
filaments that doubled as cathodes, which helped quite a bit.



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On 22/06/2017 18:56, Max Demian wrote:
On 22/06/2017 09:46, Chris Green wrote:
Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.

Mains valve radios were up and running in 20 seconds.

A lot of modern equipment takes a lot longer than that. Apart from
(obvious) computers, TVs and mobile phones have quite restricted
functionality, or are very slow to respond, until a lot of background
tasks have finished running.

Why do modern, but non-smart TVs take so long to start up? You'd have
thought they'd be up and running in seconds, but they take ages. What is
there to do other than switch on the back-light, clear the memory sync
the data stream from the last used input (or start from the next frame
when using UHF to ditribute around the house) and start displaying it?

SteveW

On 22/06/2017 09:46, Chris Green wrote:
Graeme wrote:
In message ,
writes

And being told to put the radio on at 5 to 1 for the 1 o'clock news -
it needed time to 'warm up'.

10 to 1, otherwise you'd miss the shipping forecast :-)

Many of our 'radios' (internet, etc.) take just as long to start up.
Give me a 'tranny' any day.


525 Millwatts of power for 64 bits of memory.(No, not K, M or G).

http://www.cpushack.com/2017/06/20/i...ipolar-memory/

On 22/06/2017 08:26, wrote:
On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became useless as the telephone got changed to 5ps and 10ps. (This was of course the telephone box down the road -- we didn't have one in the house.)

When STD coin box phones came in, they took threepenny bits, sixpences
and shillings. They soon blocked up the threepenny slot, so doubling the
cost of short local calls.

--
Max Demian

On 22/06/2017 18:59, Max Demian wrote:
On 22/06/2017 08:26, wrote:
On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became
useless as the telephone got changed to 5ps and 10ps. (This was of
course the telephone box down the road -- we didn't have one in the
house.)

When STD coin box phones came in, they took threepenny bits, sixpences
and shillings. They soon blocked up the threepenny slot, so doubling the
cost of short local calls.

I think it was only in the '80s that they changed the tone received by
an operator from a payphone - until then they could not tell them from
private phones and people had learned that you could make free reverse
charges calls *to* phoneboxes.

SteveW

On Friday, 23 June 2017 00:49:11 UTC+1, Steve Walker wrote:
I think it was only in the '80s that they changed the tone received by
an operator from a payphone - until then they could not tell them from
private phones and people had learned that you could make free reverse
charges calls *to* phoneboxes.

This was because the 1980s GPO/BT owned all the payphones and knew which lines were coinbox lines. It was possible to make reverse charge calls to a payphone because the operator could ask the person at the payphone to insert money to pay for the call (and on the old Button A/B boxes listen to the separate 'dings' for sixpences and shillings).

When private payphones were introduced they were connected to ordinary lines so the operators had to have some means of knowing a payphone was connected, hence the 'cuckoo' tone.

Owain

On 23/06/2017 09:09, wrote:
On Friday, 23 June 2017 00:49:11 UTC+1, Steve Walker wrote:
I think it was only in the '80s that they changed the tone received by
an operator from a payphone - until then they could not tell them from
private phones and people had learned that you could make free reverse
charges calls *to* phoneboxes.

This was because the 1980s GPO/BT owned all the payphones and knew which lines were coinbox lines. It was possible to make reverse charge calls to a payphone because the operator could ask the person at the payphone to insert money to pay for the call (and on the old Button A/B boxes listen to the separate 'dings' for sixpences and shillings).

When private payphones were introduced they were connected to ordinary lines so the operators had to have some means of knowing a payphone was connected, hence the 'cuckoo' tone.

Owain

Well BT didn't use their knowledge well, as people were making such
calls without the operators catching on from what I remember

SteveW

On Fri, 23 Jun 2017 00:49:10 +0100, Steve Walker
wrote:

On 22/06/2017 18:59, Max Demian wrote:
On 22/06/2017 08:26, wrote:
On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became
useless as the telephone got changed to 5ps and 10ps. (This was of
course the telephone box down the road -- we didn't have one in the
house.)

When STD coin box phones came in, they took threepenny bits, sixpences
and shillings. They soon blocked up the threepenny slot, so doubling the
cost of short local calls.

I think it was only in the '80s that they changed the tone received by
an operator from a payphone - until then they could not tell them from
private phones and people had learned that you could make free reverse
charges calls *to* phoneboxes.

SteveW

"Cuckoo tone"
--

Graham.
%Profound_observation%

In article
,
says...

When STD coin box phones came in, they took threepenny bits, sixpences
and shillings. They soon blocked up the threepenny slot, so doubling the
cost of short local calls.

Soon?????

I lived in Grays in Essex. In 1955, the manual Tilbury
exchange (which was actually located in Grays!) was being
replaced by a new automatic exchange (and Grays got its own
exchange for the first time).

There was an exhibition in the main Post Office
demonstrating the new STD system we were to have, with
phones that you could use to dial up various test numbers in
various places in Britain.

Thus, I think, we were probably about the first exchange to
have the new STD phone boxes. They continued to accept
threepenny bits until around 1964/5, so around 10 years.

--

Terry

On 23/06/2017 11:52, Terry Casey wrote:
In article
,
says...

When STD coin box phones came in, they took threepenny bits, sixpences
and shillings. They soon blocked up the threepenny slot, so doubling the
cost of short local calls.

Soon?????

I lived in Grays in Essex. In 1955, the manual Tilbury
exchange (which was actually located in Grays!) was being
replaced by a new automatic exchange (and Grays got its own
exchange for the first time).

There was an exhibition in the main Post Office
demonstrating the new STD system we were to have, with
phones that you could use to dial up various test numbers in
various places in Britain.

Thus, I think, we were probably about the first exchange to
have the new STD phone boxes. They continued to accept
threepenny bits until around 1964/5, so around 10 years.

I mean the ones where you put the coin in when connected as opposed to
the old button A/B type.

--
Max Demian

On Fri, 23 Jun 2017 13:58:50 +0100, Max Demian
wrote:

On 23/06/2017 11:52, Terry Casey wrote:
In article
,
says...

When STD coin box phones came in, they took threepenny bits, sixpences
and shillings. They soon blocked up the threepenny slot, so doubling the
cost of short local calls.

Soon?????

I lived in Grays in Essex. In 1955, the manual Tilbury
exchange (which was actually located in Grays!) was being
replaced by a new automatic exchange (and Grays got its own
exchange for the first time).

There was an exhibition in the main Post Office
demonstrating the new STD system we were to have, with
phones that you could use to dial up various test numbers in
various places in Britain.

Thus, I think, we were probably about the first exchange to
have the new STD phone boxes. They continued to accept
threepenny bits until around 1964/5, so around 10 years.

I mean the ones where you put the coin in when connected as opposed to
the old button A/B type.

I am sure Terry was referring to the "Pay on answer" equipment, it was
intraduced as early as 1958
--

Graham.
%Profound_observation%

On 22/06/2017 08:26, wrote:
On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became useless as the telephone got changed to
5ps and 10ps. (This was of course the telephone box down the road --
we didn't have one in the house.)

I always check my change for non-ferrous 1p and 2p pieces and save them.

Sometimes they come in handy, like making up a couple of non-corrodable
washers to hold the toilet cystern to the wall ( the two inside and
permanently damp.).

The ferrous ones I cast adrift on the South Downs where ever the
detectorists have been skulking. Makes their day.

"Andrew" wrote in message
news
On 22/06/2017 08:26, wrote:
On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage bits.

I remember when all the 2ps we'd saved for the telephone became useless
as the telephone got changed to
5ps and 10ps. (This was of course the telephone box down the road --
we didn't have one in the house.)

I always check my change for non-ferrous 1p and 2p pieces and save them.

Sometimes they come in handy, like making up a couple of non-corrodable
washers to hold the toilet cystern to the wall ( the two inside and
permanently damp.).

The ferrous ones I cast adrift on the South Downs where ever the
detectorists have been skulking. Makes their day.

didn't know that ....thanks

http://blog.royalmint.com/why-are-so...oins-magnetic/

"Jim GM4DHJ ..." wrote in message
news
I always check my change for non-ferrous 1p and 2p pieces and save them.

Sometimes they come in handy, like making up a couple of non-corrodable
washers to hold the toilet cystern to the wall ( the two inside and
permanently damp.).

The ferrous ones I cast adrift on the South Downs where ever the
detectorists have been skulking. Makes their day.

didn't know that ....thanks

http://blog.royalmint.com/why-are-so...oins-magnetic/

I knew that the "copper" coins were changed a couple of decades ago, but I
didn't know that the "silver" coins had also been changed.

On 22/06/2017 17:17, pamela wrote:
On 08:26 22 Jun 2017, wrote:

On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the
Convergenece Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage
bits.

I remember when all the 2ps we'd saved for the telephone became
useless as the telephone got changed to 5ps and 10ps. (This was
of course the telephone box down the road -- we didn't have one
in the house.)

That's posively modern. Before 2ps were used in public
telephones it was 'Press Button A'.

And if you were to pay a visit to Crich tram museum, you could use the
only working Button A/Button B payphone still in operation to make a call.

SteveW

On 23/06/2017 00:47, Steve Walker wrote:
On 22/06/2017 17:17, pamela wrote:
On 08:26 22 Jun 2017, wrote:

On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the
Convergenece Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage
bits.

I remember when all the 2ps we'd saved for the telephone became
useless as the telephone got changed to 5ps and 10ps. (This was
of course the telephone box down the road -- we didn't have one
in the house.)

That's posively modern. Before 2ps were used in public
telephones it was 'Press Button A'.

And if you were to pay a visit to Crich tram museum, you could use the
only working Button A/Button B payphone still in operation to make a call.

What do you put into it? 4d?

--
Max Demian

On 23/06/2017 13:55, Max Demian wrote:
On 23/06/2017 00:47, Steve Walker wrote:
On 22/06/2017 17:17, pamela wrote:
On 08:26 22 Jun 2017, wrote:

On Thursday, 22 June 2017 08:17:08 UTC+1, DerbyBorn wrote:
Remember trying to improve an old TV by adjusting the
Convergenece Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

Probably lots of them conveniently close to tingly high voltage
bits.

I remember when all the 2ps we'd saved for the telephone became
useless as the telephone got changed to 5ps and 10ps. (This was
of course the telephone box down the road -- we didn't have one
in the house.)

That's posively modern. Before 2ps were used in public
telephones it was 'Press Button A'.

And if you were to pay a visit to Crich tram museum, you could use the
only working Button A/Button B payphone still in operation to make a
call.

What do you put into it? 4d?

It's been adapted to take current coinage.

SteveW

Yes some of the ladies we had at rediffusion in Chessington could do purity
static and dynamic convergence on a set in about three minutes.
I really still don't know how they did it.
Seriously though. I think the secret is doing things in the correct order
or you muck it up.

Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"DerbyBorn" wrote in message
2.236...
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

Brian Gaff wrote:
Yes some of the ladies we had at rediffusion in Chessington could do purity
static and dynamic convergence on a set in about three minutes.
I really still don't know how they did it.
Seriously though. I think the secret is doing things in the correct order
or you muck it up.

I used to service valve 'scopes (Marconi Instruments and Tektronix),
these had delay lines between the final valves of the amplifers and
the tube deflection plates so that one could see the rising edge of a
pulse that had triggered the scan.

The delay lines had to be 'tuned', there were 20 or 30 trimmers at
least, you trimmed them for minimum distortion of a 'good' square wave
at the front edge. Took ages!

--
Chris Green
·

I think the thing about crts was that since the controls were all basically
either magnets or waveforms fed to the scan coils, one always affected
another. You cannot really screen one electon beam and only control that
one.
The shadow mask was of course fixed and one hoped the combined tolerances
of all the parts agreed enough that only minor adjustments were in fact
needed. the corners were always way out of course but apparently the eye
never noticed that much.

Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain. I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Chris Green" wrote in message
...
Brian Gaff wrote:
Yes some of the ladies we had at rediffusion in Chessington could do
purity
static and dynamic convergence on a set in about three minutes.
I really still don't know how they did it.
Seriously though. I think the secret is doing things in the correct
order
or you muck it up.

I used to service valve 'scopes (Marconi Instruments and Tektronix),
these had delay lines between the final valves of the amplifers and
the tube deflection plates so that one could see the rising edge of a
pulse that had triggered the scan.

The delay lines had to be 'tuned', there were 20 or 30 trimmers at
least, you trimmed them for minimum distortion of a 'good' square wave
at the front edge. Took ages!

--
Chris Green
·

On Thursday, 22 June 2017 11:00:07 UTC+1, Brian Gaff wrote:
I think the thing about crts was that since the controls were all basically
either magnets or waveforms fed to the scan coils, one always affected
another.

indeed

You cannot really screen one electon beam and only control that
one.

that has been done, but not in mass market sets. Early sequential colour systems involved doing that with a single gun tube.

The shadow mask was of course fixed

I saw one that wasn't. A weird viewing experience.

and one hoped the combined tolerances
of all the parts agreed enough that only minor adjustments were in fact
needed.

never true

the corners were always way out of course

they weren't

but apparently the eye
never noticed that much.

it did when they were

Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain.

cost.

I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.
Brian

Brian Gaff wrote:
I think the thing about crts was that since the controls were all basically
either magnets or waveforms fed to the scan coils, one always affected
another. You cannot really screen one electon beam and only control that
one.
The shadow mask was of course fixed and one hoped the combined tolerances
of all the parts agreed enough that only minor adjustments were in fact
needed. the corners were always way out of course but apparently the eye
never noticed that much.

Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain. I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.
Brian


The driving techniques for flat screen were around 40+ years ago. What
was missing was the ability to produce small enough plasma cells
reliably. The advent of LCD volume production enabled todays screens.
CRTs AIUI are still difficult to beat for high brightness/temperatre
range displays.

In article ,
Brian Gaff wrote:
Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain. I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.

Because it was a very long time - if ever - before LCD matched let alone
betered decent CRT in many ways.

CRT monitors were still in use for setting the pictures from TV cameras in
the studio etc long after they'd stopped being on sale as domestic sets.

But with domestic, a large slim cheap unit is far more important than
actual picture quality.

--
*On the other hand, you have different fingers*

Dave Plowman London SW
To e-mail, change noise into sound.

On Thursday, 22 June 2017 14:55:42 UTC+1, Dave Plowman (News) wrote:
In article ,
Brian Gaff wrote:
Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain. I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.

Because it was a very long time - if ever - before LCD matched let alone
betered decent CRT in many ways.

CRT monitors were still in use for setting the pictures from TV cameras in
the studio etc long after they'd stopped being on sale as domestic sets.

But with domestic, a large slim cheap unit is far more important than
actual picture quality.

Or program quality.
But at least Ghost hunters and ancient aliens makes me smile

On Thursday, 22 June 2017 14:55:42 UTC+1, Dave Plowman (News) wrote:
In article ,
Brian Gaff wrote:
Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain. I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.

Because it was a very long time - if ever - before LCD matched let alone
betered decent CRT in many ways.

CRT monitors were still in use for setting the pictures from TV cameras in
the studio etc long after they'd stopped being on sale as domestic sets.

But with domestic, a large slim cheap unit is far more important than
actual picture quality.

I had a passive colour screen on an early laptop, picture quality was abysmal. Huge amounts of noise & smear, and watching motion was unworkable due to excessive slowness.


NT

On Thu, 22 Jun 2017 14:53:27 +0100, Dave Plowman (News) wrote:

CRT monitors were still in use for setting the pictures from TV cameras
in the studio etc long after they'd stopped being on sale as domestic
sets.

And sound may still have a CRT for checking sync. LCDs have an
inherent delay.

--
Cheers
Dave.

"DerbyBorn" wrote in message
2.236...
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

I used to be expert at that, and colour adjustment. The TV firm I worked for
had an exhibition display of about 9 sets stacked as a pyramid in the London
Hilton Hotel. Out of our factory they were all wildly different, but I was
able to make them look the same at first glance. Outside the open door was a
line of Americans queuing for something else, and a couple of them came in
saying they'd never seen anything like it - how is it done? - is there
secret equipment in the roof? The poor souls had only had experience of NTSC
in the US, "Never Twice The Same Colour", unlike our PAL, although the main
reason in both countries was just shoddy adjustment and component drift.
--
Dave W

Dave W wrote:
"DerbyBorn" wrote in message
2.236...
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other ajustements.

I used to be expert at that, and colour adjustment. The TV firm I worked for
had an exhibition display of about 9 sets stacked as a pyramid in the London
Hilton Hotel. Out of our factory they were all wildly different, but I was
able to make them look the same at first glance. Outside the open door was a
line of Americans queuing for something else, and a couple of them came in
saying they'd never seen anything like it - how is it done? - is there
secret equipment in the roof? The poor souls had only had experience of NTSC
in the US, "Never Twice The Same Colour", unlike our PAL, although the main
reason in both countries was just shoddy adjustment and component drift.


The main problem with NTSC was multipath propagation and reflections in
distributed systems.

One of the fun devices was an electtron gun tube rejuvenator. When one of
the colours was so low emission it really needed a new tube ten mins on this
gadget seems to make it last at least another 6 months!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Capitol" wrote in message
o.uk...
Dave W wrote:
"DerbyBorn" wrote in message
2.236...
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

I used to be expert at that, and colour adjustment. The TV firm I worked
for
had an exhibition display of about 9 sets stacked as a pyramid in the
London
Hilton Hotel. Out of our factory they were all wildly different, but I
was
able to make them look the same at first glance. Outside the open door
was a
line of Americans queuing for something else, and a couple of them came
in
saying they'd never seen anything like it - how is it done? - is there
secret equipment in the roof? The poor souls had only had experience of
NTSC
in the US, "Never Twice The Same Colour", unlike our PAL, although the
main
reason in both countries was just shoddy adjustment and component drift.


The main problem with NTSC was multipath propagation and reflections in
distributed systems.

On Thu, 22 Jun 2017 11:04:58 +0100, Brian Gaff wrote:

One of the fun devices was an electtron gun tube rejuvenator. When one
of the colours was so low emission it really needed a new tube ten mins
on this gadget seems to make it last at least another 6 months!

I used similar devices back in the 1960s. I had a weekend/summer job with
Technical Trading in Brighton. They used to sell cut price valves.

They bought large quantities of used valves. We tested them using Mullard
valve testers (the ones with big punched paxolin cards for each valve
type, to select voltages and tests). If OK, we cleaned them off and
relabelled them by printing on the side.

If they had low emission, they went into an RF coil that would ignite
what was left of the getter. That usually got them to pass the test.

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On 22 Jun 2017 11:03:27 GMT, Bob Eager wrote:

On Thu, 22 Jun 2017 11:04:58 +0100, Brian Gaff wrote:

One of the fun devices was an electtron gun tube rejuvenator. When one
of the colours was so low emission it really needed a new tube ten mins
on this gadget seems to make it last at least another 6 months!

I used similar devices back in the 1960s. I had a weekend/summer job with
Technical Trading in Brighton. They used to sell cut price valves.

They bought large quantities of used valves. We tested them using Mullard
valve testers (the ones with big punched paxolin cards for each valve
type, to select voltages and tests). If OK, we cleaned them off and
relabelled them by printing on the side.

If they had low emission, they went into an RF coil that would ignite
what was left of the getter. That usually got them to pass the test.


Technical Trading in Brighton, now there's a blast from the past. I
can remember avidly waiting foe a parcel from TT when I was a
schoolkid, but, I can't remember what it was.
There always seemed to be an intervening Bank Holiday to extend the
suspense, when I ordered something interesting.


--

Graham.
%Profound_observation%

On 22/06/2017 10:20, Capitol wrote:
Dave W wrote:
"DerbyBorn" wrote in message
2.236...
Remember trying to improve an old TV by adjusting the Convergenece
Controls.
I recall, my old Murphy had about 20 potentiometers and other
ajustements.

I used to be expert at that, and colour adjustment. The TV firm I
worked for
had an exhibition display of about 9 sets stacked as a pyramid in the
London
Hilton Hotel. Out of our factory they were all wildly different, but I
was
able to make them look the same at first glance. Outside the open door
was a
line of Americans queuing for something else, and a couple of them
came in
saying they'd never seen anything like it - how is it done? - is there
secret equipment in the roof? The poor souls had only had experience
of NTSC
in the US, "Never Twice The Same Colour", unlike our PAL, although the
main
reason in both countries was just shoddy adjustment and component drift.


The main problem with NTSC was multipath propagation and
reflections in distributed systems.

I always thought it was the purple and green flashing makeup the US
newscasters used. Later they clamped chroma for everything near flesh
tones to surreal pale orange. Neither looked anything like realistic.

There was nothing much wrong with the NTSC standard itself - Japan used
a variant of NTSC but implemented it very much better just like they did
with RIAA equalisation on consumer phono pickups. PAL had the huge
advantage that systematic phase shifts were automagically cancelled out.

--
Regards,
Martin Brown