[Ian Jackson]

In message , Don Pearce
writes
On Tue, 15 Dec 2009 08:58:52 +0000, Ian Jackson
wrote:

In message , Don Pearce
writes
On Mon, 14 Dec 2009 19:50:10 GMT, "Brian Gaff"
wrote:

Who recalls the RT and VC kit transistor radio called the Elegant 7,
refering to a whole seven transistors!
I built one of these, but the output transistors were faulty and after ten
minutes they would get very hot and the output would stop. Tuurn it off for
a few minutes and it did it all again. In the end the company sent us a set
of matched GET 114s and all was well!

Brian

Sorry you can't see this, but here's the original ad for the Elegant
Seven at four guineas. Also on this page is my first ever valve amp an
SET (tetrode not triode) down on the right - 3 to 4 watts, it says. It
even worked.

http://www.soundthoughts.co.uk/look/seven.jpg

I made an Elegant 7 for my mother-in-law. I still have it. I modified
the mains power supply so it would also trickle-charge the 9V
(non-rechargeable) battery (which works - provided you start with a new
battery, don't let it discharge too much, and don't over-do the charging
current). I remember it being not the most sensitive of radios, and
unusually noisy. [I think that some the cheap multi-layer capacitors of
the time were bad for that.] Must dig it out, see if it still works, and
maybe fix the 43 year-old noise problem.

I suspect there will be bigger problems today with the amount of
electronic garbage flying round in the air, but it would be
interesting to see how it holds up.

I don't think that there's any reason to suspect that the Elegant 7
won't perform just as well as a 'new' LW/MW portable radio. Apart from
ceramic IF transformers, the design will be essentially identical.

I think I would be going for the
transistors before the caps in a noise search though.

Yes, the transistors are the obvious suspects, but I remember reading
(long ago) that some dodgy multi-layer ceramic capacitors can produce
noise.
--
Ian

[Don Pearce[_3_]]

On Tue, 15 Dec 2009 13:27:43 +0000, Ian Jackson
wrote:

I think I would be going for the
transistors before the caps in a noise search though.

Yes, the transistors are the obvious suspects, but I remember reading
(long ago) that some dodgy multi-layer ceramic capacitors can produce
noise.
--

Yes they made them in big sheets then chopped them up, leaving jagged
bits hanging off the edges. These would make contact with the main
part of the cap intermittently by arcing, resulting in noise. These
days they all have their edges polished to stop this.

d

[Arny Krueger]

"Don Pearce" wrote in message

Interesting insight into the way things were in the 60s -
I've just been reading a Wireless World from November of
that year. Valves (tubes for those across the pond) were
extremely cheap. And transistors cost pretty much the
same, which is why we treated them with kid gloves and
thermal shunts when soldering them into circuits.

http://www.soundthoughts.co.uk/look/valves.jpg

Money conversion for the young and foreign:

20 shillings to the pound, 12 pence to the shilling. A
price given as 5/6 meant five shillings and six pence. So
an ECC84 at 6/6 is 32.5 pence in today's money. A 28012
transistor, by contrast at 140/- is seven pounds -
getting on for half the weekly wage of some people back
then.

I may post some ads for complete equipment later, just to
make you cry.

I'm betting that Kitty will tell us that he's never had to replace a tube.
;-)

[Ian Jackson]

In message , Don Pearce
writes
On Tue, 15 Dec 2009 13:27:43 +0000, Ian Jackson
wrote:

I think I would be going for the
transistors before the caps in a noise search though.

Yes, the transistors are the obvious suspects, but I remember reading
(long ago) that some dodgy multi-layer ceramic capacitors can produce
noise.
--

Yes they made them in big sheets then chopped them up, leaving jagged
bits hanging off the edges. These would make contact with the main
part of the cap intermittently by arcing, resulting in noise. These
days they all have their edges polished to stop this.

Thanks for that info. I'll Google to see if I can find more.
--
Ian

[Ian Bell[_2_]]

David Looser wrote:
"Ian Bell" wrote
I had some of those too. There were also green spot rf ones. I still have
a red spot one. Must be worth a fortune now ;-)


If they are worth a fortune I'm sitting on a gold-mine here!

David.




I also have some 'top hat' types XA???

Cheers

Ian

[Ian Bell[_2_]]

Phil Allison wrote:
"Brian Gaff"
I think one has to be careful if buying the Chinese copies of valves
around at the current time, as quality control is almost non existent,
though some Russian ones are made a lot better I'm told.



** Why refer to them as " Chinese copies of valves " ??

My info is that the Chinese purchased valve making equipment ( including
dies and materials) from Europe when factories there closed in the 1980s and
transported it to China.

This is so they could easily start making popular audio valves like EL34s,
6L6s and 12AX7s - for which there were no equivalent Chinese types in
production at the time.



.... Phil




That assumes that all that is required to make good tubes is the
equipment. Whether or not the Chinese have the necessary know how as
well is moot.

Cheers

Ian

[David Looser]

"Ian Bell" wrote

That assumes that all that is required to make good tubes is the
equipment. Whether or not the Chinese have the necessary know how as well
is moot.


I'm sure that the nation that invented printing, gunpowder and bone china
(amongst many other things) won't have much problem in acquiring the
necessary know-how.

David.

[Phil Allison[_3_]]

"Ian Bell= ****ing RATBAG MORON"

Phil Allison wrote:
"Brian Gaff"
I think one has to be careful if buying the Chinese copies of valves
around at the current time, as quality control is almost non existent,
though some Russian ones are made a lot better I'm told.



** Why refer to them as " Chinese copies of valves " ??

My info is that the Chinese purchased valve making equipment ( including
dies and materials) from Europe when factories there closed in the 1980s
and transported it to China.

This is so they could easily start making popular audio valves like
EL34s, 6L6s and 12AX7s - for which there were no equivalent Chinese
types in production at the time.



That assumes that all that is required to make good tubes is the
equipment.


** There is no such assumption within or behind my post

- you ****ing ASININE TENTH WIT !!!



...... Phil

[Phil Allison[_3_]]

"David Loser"
"Ian Bell ****ing RATBAG "

That assumes that all that is required to make good tubes is the
equipment. Whether or not the Chinese have the necessary know how as well
is moot.


I'm sure

** LOL - Loser is never sure if his ARSE e is on fire or nor !!

that the nation that invented printing, gunpowder and bone china (amongst
many other things) won't have much problem in acquiring the necessary
know-how.


** Shame all the EVIDENCE of the last 20+ years says the exact opposite -
ie Chinese audio valves are still of relatively* poor quality and with very
poor quality control as well.

Virtually all of them come from just one Chinese maker, " Shuguang Electron
Group Co Ltd."

http://www.shuguangelec.com/en/profile.asp


( * relatively = relative to the US, UK and major European brands before
they ceased operations )



...... Phil

[Ian Iveson]

David Looser wrote:

That assumes that all that is required to make good tubes
is the equipment. Whether or not the Chinese have the
necessary know how as well is moot.


I'm sure that the nation that invented printing, gunpowder
and bone china (amongst many other things) won't have much
problem in acquiring the necessary know-how.

Columbus set off with a Chinese map of the world, including
America in its proper location, drawn up before the Chinese
fleet was recalled because of a long period of war. As with
the UK, that fleet was made from pretty much all the trees
they had, which was a lot of trees. Then, as now, they
traded throughout the world without involving themselves in
the politics of distant places, and in the end they all went
home. Gunpowder but no guns, according to my edition of
"Shogun", in which the marauding Mongols arrive with
"thunder bombers", who set fire to bags of powder and hurl
them. Best used downhill against approaching heavy cavalry
so even if the bombers blow themselves up they still
frighten the horses. Guns arrived from Europe, much later.

The Chinese are generally well educated and just as clever
as other humans, so they aren't short of scientific and
engineering knowledge. What they must lack is an adequate
number of experienced technicians who are able to deal with
the everyday variations in industial production processes.
Not just in the assembly but also in the production of the
special materials. The machinery was made in the days when
production managers and technicians needed a real feel for
what they did.

Economically, it seems probable that the plants had become
"cash cows" before they went to China, and have remained so
since. Basically, plants producing products on the down side
of the product life cycle require little invesment and
produce cash until they eventually die. A cash cow is
typically matched with the manufacture of new products on
the rising side of the cycle, which consumes cash because of
continuous growth in turnover. Working for a cash cow is
thoroughly demoralising, especially for engineers. Patrick's
worst nightma all bean counting but with absolutely no
beans...extreme make-do-and-mend.

Anyway, for the kind of pace of development in China, plenty
of cash cows are a good alternative to debt, I guess. That's
presumably why they're buying car and aircraft plants for
old models, and countless other examples of outdated but
cheap and functional stuff.

Even if you had all the "know-how" would you, as a
businessman, invest money in producing an improved valve?
Would you replace all those worn machine tools and jigs?
Include the cost of not investing in something sensible.

It's not just the Chinese. *No-one else* was prepared to
invest in those plants. That's why they went to China.

Ian

[David Looser]

"Ian Iveson" wrote

Columbus set off with a Chinese map of the world, including America in its
proper location, drawn up before the Chinese fleet was recalled because of
a long period of war. As with the UK, that fleet was made from pretty much
all the trees they had, which was a lot of trees.

So where does this little bit of bogus "history" come from?


The Chinese are generally well educated and just as clever as other
humans, so they aren't short of scientific and engineering knowledge.

Exactly.

Economically, it seems probable that the plants had become "cash cows"
before they went to China, and have remained so since.

Indeed, would valve quality have been any better had the production
equipment stayed in Europe or the US? Both continents make some pretty
shoddy products as well as some superb ones.

David.

[Ian Bell[_2_]]

Phil Allison wrote:
"Ian Bell= ****ing RATBAG MORON"
Phil Allison wrote:
"Brian Gaff"
I think one has to be careful if buying the Chinese copies of valves
around at the current time, as quality control is almost non existent,
though some Russian ones are made a lot better I'm told.


** Why refer to them as " Chinese copies of valves " ??

My info is that the Chinese purchased valve making equipment ( including
dies and materials) from Europe when factories there closed in the 1980s
and transported it to China.

This is so they could easily start making popular audio valves like
EL34s, 6L6s and 12AX7s - for which there were no equivalent Chinese
types in production at the time.


That assumes that all that is required to make good tubes is the
equipment.


** There is no such assumption within or behind my post

- you ****ing ASININE TENTH WIT !!!



..... Phil




And a Merry Christmas and a Healthy New Year to you too Phil

Cheers

Ian

[Andre Jute[_2_]]

On Dec 16, 1:05*am, "Phil Allison" wrote:
"David Loser"
"Ian Bell ****ing RATBAG "



That assumes that all that is required to make good tubes is the
equipment. Whether or not the Chinese have the necessary know how as well
is moot.

I'm sure

** * LOL * - Loser is never sure if his ARSE e is on fire or nor !!

that the nation that invented printing, gunpowder and bone china (amongst
many other things) won't have much problem in acquiring the necessary
know-how.

** Shame all the EVIDENCE *of the last 20+ years says the exact opposite -
ie Chinese audio valves are still of relatively* poor quality and with very
poor quality control as well.

Virtually all of them come from just one Chinese maker, " Shuguang Electron
Group Co Ltd."

http://www.shuguangelec.com/en/profile.asp

( * relatively *= *relative to the US, UK and major European brands before
they ceased operations )

..... * Phil

The Chinese had a huge headstart in all that knowledge, and having the
machinery; they should have enjoyed all of what is known in economics
as "the advantages of backwardness". If the Chinese were interested in
making good tubes, it would have happened by now. I think we can
assume they're interested in volume well before quantity. No amount of
creepy leftwing excuses can change the outcome: after 20+ years,
Chinese tube quality is *very* patchy.

Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review

[David Looser]

"Andre Jute" wrote

The Chinese had a huge headstart in all that knowledge, and having the
machinery; they should have enjoyed all of what is known in economics
as "the advantages of backwardness". If the Chinese were interested in
making good tubes, it would have happened by now. I think we can
assume they're interested in volume well before quantity. No amount of
creepy leftwing excuses can change the outcome: after 20+ years,
Chinese tube quality is *very* patchy.


Which is all beside the point. The Chinese have the know-how, whether they
choose to use it is another matter entirely. If they all come from the same
maker then there is no competitive pressure to improve quality. That's the
way capitalism works, nothing to do with "leftwing excuses".

David.

[Ian Iveson]

David Looser wrote:

Columbus set off with a Chinese map of the world,
including America in its proper location, drawn up before
the Chinese fleet was recalled because of a long period
of war. As with the UK, that fleet was made from pretty
much all the trees they had, which was a lot of trees.

So where does this little bit of bogus "history" come
from?

Since you've already decided it's bogus, why do you want to
know?

I'd be quite interested to know *why* you think it's bogus,
in particular? Pretty much all of history regularly turns
out to be bogus, more or less, in one way or another. The
Chinese were remarkably absent from my school history,
except for some passing mention of Marco Polo, who made
stuff up.

Actually, as with much of my view of history, I can't
remember where the Chinese world map story came from.
Possibly a TV documentary. Of course the details are open to
doubt, but the generality...that Chinese maps of the world
were available before European ones...seems to be generally
accepted. I judge it unlikely that such a huge trading fleet
could have managed to keep its maps secret from the
Europeans.

http://www.chengho.org/news/chinesemap.php

Is what a casual Google came up with. I wonder what's
happened since then?

Makes a nice story anyway. The island of California is an
interesting error. I can see how it might have been made by
explorers arriving from the Pacific, but not by those
arriving by land or along the coast, and yet it appears on
European maps.

The Chinese are generally well educated and just as
clever as other humans, so they aren't short of
scientific and engineering knowledge.

Exactly.

Economically, it seems probable that the plants had
become "cash cows" before they went to China, and have
remained so since.

Indeed, would valve quality have been any better had the
production equipment stayed in Europe or the US? Both
continents make some pretty shoddy products as well as
some superb ones.

Agreed. Of course.

Ian

[David Looser]

"Ian Iveson" wrote in message
...
David Looser wrote:

Columbus set off with a Chinese map of the world, including America in
its proper location, drawn up before the Chinese fleet was recalled
because of a long period of war. As with the UK, that fleet was made
from pretty much all the trees they had, which was a lot of trees.

So where does this little bit of bogus "history" come from?

Since you've already decided it's bogus, why do you want to know?

I'd be quite interested to know *why* you think it's bogus, in particular?

OK, "bogus" was too strong. The map is interesting I agree, and I'm
certainly not calling *it* "bogus, though as yet it's authenticity is
unproven. But who says that Columbus had a copy? Of course we now know that
the Vikings briefly colonised North America in the 14th C, though it's very
unlikely that Columbus would have known about that.

I suppose the phrase that really triggered my use of "bogus" was "As with
the UK, that fleet was made from pretty much all the trees they had, which
was a lot of trees". Do you *really* believe that the British fleet, let
alone the Chinese one, represented "pretty much all the trees they had"?

It's well accepted that the Chinese were at one time a major sea-faring and
trading nation and had excellent ship building skills. Later for reasons
that remain obscure they gave up sea-borne trade and turned inward. The
phrase "the Chinese fleet was recalled because of a long period of war"
doesn't line up with anything I've ever read. I've seen it argued that one
reason that the Chinese-built Mongol fleet for the invasion of Japan was
lost so dramatically in a storm (the original Kamikaze, which means "Divine
Wind") was that the Chinese ship builders, who were working under
sufferance, deliberately constructed the ships to be unseaworthy.

David.

[Ian Iveson]

David Looser wrote:

Columbus set off with a Chinese map of the world,
including America in its proper location, drawn up
before the Chinese fleet was recalled because of a long
period of war. As with the UK, that fleet was made from
pretty much all the trees they had, which was a lot of
trees.

So where does this little bit of bogus "history" come
from?

Since you've already decided it's bogus, why do you want
to know?

I'd be quite interested to know *why* you think it's
bogus, in particular?

OK, "bogus" was too strong. The map is interesting I
agree, and I'm certainly not calling *it* "bogus, though
as yet it's authenticity is unproven. But who says that
Columbus had a copy? Of course we now know that the
Vikings briefly colonised North America in the 14th C,
though it's very unlikely that Columbus would have known
about that.

But nonetheless likely that he had a copy of the Chinese
one. The story went that it was presented to the King of
Spain as some kind of gift or tribute. If the Chinese had
ceased trading, then they would have nothing to lose.

I suppose the phrase that really triggered my use of
"bogus" was "As with the UK, that fleet was made from
pretty much all the trees they had, which was a lot of
trees". Do you *really* believe that the British fleet,
let alone the Chinese one, represented "pretty much all
the trees they had"?

An overstatement big enough to be obvious hyperbole, I
thought. I do think it true that shipbuilding, here and in
China, became increasingly constrained by a shortage of
suitable remaining trees. I guess that only certain kinds
and sizes of tree were suitable though. Their ships were
much bigger, and there were lots of them, so it seems
reasonable to assume that they used proportionately more
trees. Others were used for houses or fuel. Wherever all
that story came from, I suppose I assimilated it because it
fitted with whatever I thought I already knew.

So, as a matter of interest, how many trees are needed to
make a ship, and how many ships were made? How many trees
are there in a square mile of forest?

And where *did* all the trees go?

Wasn't there a long period of civil and local wars around
what is now China? Perhaps involving Korea and other
emerging border states, and areas which are now China but
weren't at the time?

It's well accepted that the Chinese were at one time a
major sea-faring and trading nation and had excellent ship
building skills. Later for reasons that remain obscure
they gave up sea-borne trade and turned inward. The phrase
"the Chinese fleet was recalled because of a long period
of war" doesn't line up with anything I've ever read. I've
seen it argued that one reason that the Chinese-built
Mongol fleet for the invasion of Japan was lost so
dramatically in a storm (the original Kamikaze, which
means "Divine Wind") was that the Chinese ship builders,
who were working under sufferance, deliberately
constructed the ships to be unseaworthy.

Neither sounds likely as an explanation for why so many
ships seemed to disappear from history. For some reason they
stopped trading all over the world. War at home seems a more
likely cause. Ships don't seem to last long at the best of
times, and once the wars were over they couldn't build more
because they ran out of suitable trees and the age of big
wooden ships was over.

Ian

[Trevor Wilson]

"David Looser" wrote in message
...
"Ian Bell" wrote

That assumes that all that is required to make good tubes is the
equipment. Whether or not the Chinese have the necessary know how as well
is moot.


I'm sure that the nation that invented printing, gunpowder and bone china
(amongst many other things) won't have much problem in acquiring the
necessary know-how.

**I keep a large box, full of Chinese valves, I purchased to service
equipment. They're all buggered and they're all new or very close to new. I
keep them to remind myself NEVER to buy Chinese valves (unless there is
simply no alternative). Russian valves, by comparison, are generally much,
much better. NOS American, German, Australian and British are better still.

Ah, I remember paying AUS$25.00 each for GE-MOV KT88s. Good times. Great
valves. One of my instructors was on the team that developed the KT88.

--
Trevor Wilson
www.rageaudio.com.au

[Phil Allison[_3_]]

"Trevor Wilson"

**I keep a large box, full of Chinese valves, I purchased to service
equipment. They're all buggered and they're all new or very close to new.
I keep them to remind myself NEVER to buy Chinese valves (unless there is
simply no alternative).

** So you have not bought any Chinese made valves in a long time.

Russian valves, by comparison, are generally much, much better.


** Found that to be true of the power types (ie EL34, EL84, 6L6 & 6550s )
but not so very much in the case of 'X7s and 'T7s.


NOS American, German, Australian and British are better still.


** How many of these have you bought lately?

The last time I saw any US made Philips/Sylvania 6L6GCs or 6550As
advertised, they were asking well over $100 each and the sky is the limit
for genuine Mullard EL34s.

Collectors items only - not parts for use in real amps any more.


Ah, I remember paying AUS$25.00 each for GE-MOV KT88s.


** That would have to be about 40 years ago.

******.


..... Phil

[mick]

On Tue, 15 Dec 2009 12:18:39 +0000, Jim Lesurf wrote:

In article , David Looser
wrote:
"Ian Bell" wrote

I had some of those too. There were also green spot rf ones. I still
have a red spot one. Must be worth a fortune now ;-)


If they are worth a fortune I'm sitting on a gold-mine here!

I think I have some old 'Newmarket' (if that was the name) transistors.
Maybe if these kinds of things are now 'historic relics' I should dig
some of them out... :-) IIRC they are still in the corrugated
cardboard in the boxes in which they were bought.



Would those be the ones in the flat cans with yellow & green spots for
audio and a red spot for RF, Jim?

Interesting page for flat cans:
http://homepages.nildram.co.uk/~wylie/NKT/newmarket.htm

Another for "top hat" cans:
http://homepages.nildram.co.uk/~wyli...an/Ediswan.htm

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

[Dave Plowman (News)]

In article ,
mick wrote:
Would those be the ones in the flat cans with yellow & green spots for
audio and a red spot for RF, Jim?

IIRC, it was white spot for RF, green/yellow for IF and red for audio.

--
*Why are a wise man and a wise guy opposites? *

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

[Ian Bell[_2_]]

mick wrote:
On Tue, 15 Dec 2009 12:18:39 +0000, Jim Lesurf wrote:

In article , David Looser
wrote:
"Ian Bell" wrote
I had some of those too. There were also green spot rf ones. I still
have a red spot one. Must be worth a fortune now ;-)


If they are worth a fortune I'm sitting on a gold-mine here!
I think I have some old 'Newmarket' (if that was the name) transistors.
Maybe if these kinds of things are now 'historic relics' I should dig
some of them out... :-) IIRC they are still in the corrugated
cardboard in the boxes in which they were bought.



Would those be the ones in the flat cans with yellow & green spots for
audio and a red spot for RF, Jim?

Interesting page for flat cans:
http://homepages.nildram.co.uk/~wylie/NKT/newmarket.htm

Another for "top hat" cans:
http://homepages.nildram.co.uk/~wyli...an/Ediswan.htm


Those are the ones i have - XA101 and XA102. Ediswan, now there's a name
to conjure with.

Cheers

iaN

[David Looser]

"Ian Iveson" wrote in message
...
David Looser wrote:


OK, "bogus" was too strong. The map is interesting I agree, and I'm
certainly not calling *it* "bogus, though as yet it's authenticity is
unproven. But who says that Columbus had a copy? Of course we now know
that the Vikings briefly colonised North America in the 14th C, though
it's very unlikely that Columbus would have known about that.

But nonetheless likely that he had a copy of the Chinese one.

Extremely *unlikely* I'd have thought. The general view in Europe at the
time was that if you sailed west across the Atlantic long enough you'd reach
Asia, and there is no evidence that I know of that Columbus knew different.
The object of the exercise was to create a direct link with the spice
islands, bypassing the Arab monopoly on the overland route. And why did
Columbus call the Caribbean the "West Indies" if he knew there was another
continent and another major ocean between there and India?

The story went that it was presented to the King of Spain as some kind of
gift or tribute.

There are many stories, not all are true. ;-)

If the Chinese had
ceased trading, then they would have nothing to lose.

. I do think
it true that shipbuilding, here and in China, became increasingly
constrained by a shortage of suitable remaining trees. I guess that only
certain kinds and sizes of tree were suitable though.

I'm not sure that's true. It was certainly the case here that the Government
managed several forests specifically to provide timber for ships for the
Royal Navy.

Their ships were
much bigger, and there were lots of them, so it seems reasonable to assume
that they used proportionately more trees.

But then China is a lot bigger than the UK!

And where *did* all the trees go?

In the UK mostly as firewood or simply cleared to make way for agriculture.

Wasn't there a long period of civil and local wars around what is now
China? Perhaps involving Korea and other emerging border states, and areas
which are now China but weren't at the time?

Was there?


Neither sounds likely as an explanation for why so many ships seemed to
disappear from history. For some reason they stopped trading all over the
world. War at home seems a more likely cause. Ships don't seem to last
long at the best of times, and once the wars were over they couldn't build
more because they ran out of suitable trees and the age of big wooden
ships was over.


The story I heard (from a TV documentary about Zheng He) was that China
became more inward looking at that time and adopted an isolationist policy
towards the outside world. There was no suggestion that it was anything to
do with either wars or a lack of trees.

David.

[Don Pearce[_3_]]

On Sat, 19 Dec 2009 10:13:01 -0000, "David Looser"
wrote:

But nonetheless likely that he had a copy of the Chinese one.

Extremely *unlikely* I'd have thought. The general view in Europe at the
time was that if you sailed west across the Atlantic long enough you'd reach
Asia, and there is no evidence that I know of that Columbus knew different.
The object of the exercise was to create a direct link with the spice
islands, bypassing the Arab monopoly on the overland route. And why did
Columbus call the Caribbean the "West Indies" if he knew there was another
continent and another major ocean between there and India?

Columbus was essentially clueless. He knew nothing about America and
never went there until long after it was discovered by John Cabot
(1497). Even then it was South America he visited, not North America.
All he managed to do was wander around the outer reaches of the
Caribbean for a while before being forced home.

As for the West Indies business, well if Columbus was a bit better at
Geography, he would have called them the East Indies, because he knew
he needed to go further West to find the real ones.

d

[Jim Lesurf[_2_]]

In article , mick
wrote:
On Tue, 15 Dec 2009 12:18:39 +0000, Jim Lesurf wrote:


I think I have some old 'Newmarket' (if that was the name)
transistors. Maybe if these kinds of things are now 'historic relics'
I should dig some of them out... :-) IIRC they are still in the
corrugated cardboard in the boxes in which they were bought.



Would those be the ones in the flat cans with yellow & green spots for
audio and a red spot for RF, Jim?

Interesting page for flat cans:
http://homepages.nildram.co.uk/~wylie/NKT/newmarket.htm

Another for "top hat" cans:
http://homepages.nildram.co.uk/~wyli...an/Ediswan.htm

Crumbs! People have webpages for everything! :-)

Afraid that at the moment I'm not sure which types they are. Not looked at
them for ages.

I think they are in metal cylindrical cans with no flange. They are in a
drawer 'at work'. All being well I'll be popping in to work next week
before Xmas to give good wishes and borrow an oscillator. If I remember
I'll have a look and report what they are. They are part of a stock of ye
anciente components that somehow were left over from days or yore. Never
throw anything away.... I still have a PX4 or 25 IIRC that I use to show
undergrads what electronics used to be like in the days before even *I*
were a lad! :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

[David Looser]

"Jim Lesurf" wrote

.. I still have a PX4 or 25 IIRC that I use to show
undergrads what electronics used to be like in the days before even *I*
were a lad! :-)


You mean you aren't using it in an SET amplifier? That'd be *real* HiFi that
would!



David.

[Jim Lesurf[_2_]]

In article , David Looser
wrote:
"Jim Lesurf" wrote

. I still have a PX4 or 25 IIRC that I use to show
undergrads what electronics used to be like in the days before even
*I* were a lad! :-)


You mean you aren't using it in an SET amplifier? That'd be *real* HiFi
that would!

The one I have is 'gassed' so doesn't work. I did have a number of old
valves, including PX4 and PX25 types. But over a decade ago I
sold/exchanged the ones that were OK rather than have them sitting doing
nowt when there were clearly people who wanted to use them. Just kept a few
examples for 'educational examples' or as spares for a few valve items I
have.

That said, I did have one of my summer project students once develop a
single-ended transistor amp that used an output transformer, just to play
with. So 'SET' I guess, if T = Transistor. ;-

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

[mick]

On Sat, 19 Dec 2009 00:21:41 +0000, Dave Plowman (News) wrote:

In article ,
mick wrote:
Would those be the ones in the flat cans with yellow & green spots for
audio and a red spot for RF, Jim?

IIRC, it was white spot for RF, green/yellow for IF and red for audio.


Quite possible, Dave. I've not had anything to do with those thingies for
many years! I remember that the black glass transistors were red spot for
AF and white spot for RF. Dunno about the flat cans though. I did have a
couple for a while though (and might still have somewhere!)

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

[David Looser]

"Jim Lesurf" wrote

That said, I did have one of my summer project students once develop a
single-ended transistor amp that used an output transformer, just to play
with. So 'SET' I guess, if T = Transistor. ;-


As used in car radios at one time. Hybid and early all-transistor car radios
mostly seemed to use a Class-A single-ended power transistor (OC16 or
similar) output stage rather than a Class-B push-pull pair. I guess it was
cheaper and the much higher power consumption of Class-A didn't matter much
in a car.

David.

[Don Pearce[_3_]]

On Sun, 20 Dec 2009 10:12:17 -0000, "David Looser"
wrote:

"Jim Lesurf" wrote

That said, I did have one of my summer project students once develop a
single-ended transistor amp that used an output transformer, just to play
with. So 'SET' I guess, if T = Transistor. ;-


As used in car radios at one time. Hybid and early all-transistor car radios
mostly seemed to use a Class-A single-ended power transistor (OC16 or
similar) output stage rather than a Class-B push-pull pair. I guess it was
cheaper and the much higher power consumption of Class-A didn't matter much
in a car.


Ah, those old Motorola medium and long wave beasts. I remember them
well, with their five mechanical push button tuners.

d

[Jim Lesurf[_2_]]

In article , David Looser
wrote:
"Jim Lesurf" wrote

That said, I did have one of my summer project students once develop a
single-ended transistor amp that used an output transformer, just to
play with. So 'SET' I guess, if T = Transistor. ;-


As used in car radios at one time. Hybid and early all-transistor car
radios mostly seemed to use a Class-A single-ended power transistor
(OC16 or similar) output stage rather than a Class-B push-pull pair. I
guess it was cheaper and the much higher power consumption of Class-A
didn't matter much in a car.

I guess designers of commercial audio amps back then were more habituated
to using transformers than nowdays. I didn't know about the above, but
recall that some early domestic transistor amps included things like
coupling transformers.

BTW Not sure if I'll be able to look at the Newmarket devices tomorrow. May
be delayed by snow! :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

[Don Pearce[_3_]]

On Sun, 20 Dec 2009 12:22:40 +0000 (GMT), Jim Lesurf
wrote:

I guess designers of commercial audio amps back then were more habituated
to using transformers than nowdays. I didn't know about the above, but
recall that some early domestic transistor amps included things like
coupling transformers.

How about a current guitar practice amplifier?

http://www.soundthoughts.co.uk/look/pignose.jpg

The idea is to sound like a proper valve guitar amplifier, and it sort
of does it.

d

[Jim Lesurf[_2_]]

In article , Don Pearce
wrote:
On Sun, 20 Dec 2009 12:22:40 +0000 (GMT), Jim Lesurf
wrote:

I guess designers of commercial audio amps back then were more
habituated to using transformers than nowdays. I didn't know about the
above, but recall that some early domestic transistor amps included
things like coupling transformers.

How about a current guitar practice amplifier?

http://www.soundthoughts.co.uk/look/pignose.jpg

The idea is to sound like a proper valve guitar amplifier, and it sort
of does it.

The transformers look quite small. What's the scale of the picture?

I did once do a 'theoretical' design using two bipolars and couple of
transformers to make a SET power amp, just to work out what kind of gain,
etc, you might get. But never built it as it didn't seem worth trying to
get suitable transformers. Maybe the above did it anyway? :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

[Arny Krueger]

"David Looser" wrote in
message
"Jim Lesurf" wrote

That said, I did have one of my summer project students
once develop a single-ended transistor amp that used an
output transformer, just to play with. So 'SET' I guess,
if T = Transistor. ;-

As used in car radios at one time. Hybid and early
all-transistor car radios mostly seemed to use a Class-A
single-ended power transistor (OC16 or similar) output
stage rather than a Class-B push-pull pair. I guess it
was cheaper and the much higher power consumption of
Class-A didn't matter much in a car.

Probably driven by the then-current high price of power transistors.

If memory serves, there was a period of time where most of the car radio was
built from tubes that used +12 volts for the B+, and a single power
transistor in the output stage. This eliminated the need for a vibrator and
power transformer to create more typical B+ voltages.

[Phil Allison[_3_]]

"Jim Lesurf"


I guess designers of commercial audio amps back then were more habituated
to using transformers than nowdays. I didn't know about the above, but
recall that some early domestic transistor amps included things like
coupling transformers.


** The use of coupling transformers disappeared by the early 70s in ( new)
domestic hi- fi amplifiers.

However, one famous British maker of "professional" audio revived the idea
in the early 80s - a massive leap backwards if there ever was one. Hill
Audio Ltd of Kent.

http://www.hill-audio.com/?page_id=4

Hill produced thousands of truly awful DX700 and DX1000 et alia models that
internally consisted simply of a TO220 style audio amp IC ( TDAxxxx )
driving a transformer and thence rows of Motorola MJ15024s - labelled
with their own number. These ugly boat anchors had huge toroidal
transformers, heatsinks that simply didn't and no fan.

The only overload / SOA protection for the MJs were DC rail fuses.

It blew up if ever it got hot, the speaker cable shorted or the driver
tranny wiggled loose on the PCB.

Most primitive power amps I ever saw.



..... Phil

[David Looser]

"Jim Lesurf" wrote in message
...
In article , Don Pearce
wrote:
On Sun, 20 Dec 2009 12:22:40 +0000 (GMT), Jim Lesurf
wrote:

I guess designers of commercial audio amps back then were more
habituated to using transformers than nowdays. I didn't know about the
above, but recall that some early domestic transistor amps included
things like coupling transformers.

How about a current guitar practice amplifier?

http://www.soundthoughts.co.uk/look/pignose.jpg

The idea is to sound like a proper valve guitar amplifier, and it sort
of does it.

The transformers look quite small. What's the scale of the picture?

They do, compare with the size of the screw-heads.

I did once do a 'theoretical' design using two bipolars and couple of
transformers to make a SET power amp, just to work out what kind of gain,
etc, you might get. But never built it as it didn't seem worth trying to
get suitable transformers. Maybe the above did it anyway? :-)


That looks like a push-pull amp to me. Aren't those a pair of TO220
transistors either side of the larger transformer?

avid.

[Dave Plowman (News)]

In article ,
David Looser wrote:
"Jim Lesurf" wrote in message
...
In article , Don Pearce
wrote:
On Sun, 20 Dec 2009 12:22:40 +0000 (GMT), Jim Lesurf
wrote:

I guess designers of commercial audio amps back then were more
habituated to using transformers than nowdays. I didn't know about the
above, but recall that some early domestic transistor amps included
things like coupling transformers.

How about a current guitar practice amplifier?

http://www.soundthoughts.co.uk/look/pignose.jpg

The idea is to sound like a proper valve guitar amplifier, and it sort
of does it.

The transformers look quite small. What's the scale of the picture?

They do, compare with the size of the screw-heads.

I did once do a 'theoretical' design using two bipolars and couple of
transformers to make a SET power amp, just to work out what kind of
gain, etc, you might get. But never built it as it didn't seem worth
trying to get suitable transformers. Maybe the above did it anyway?
:-)


That looks like a push-pull amp to me. Aren't those a pair of TO220
transistors either side of the larger transformer?

The size of the output transformer looks more suited to 1 watt types.

--
*Can atheists get insurance for acts of God? *

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

[David Looser]

"Dave Plowman (News)" wrote in message
...
In article ,
David Looser wrote:


That looks like a push-pull amp to me. Aren't those a pair of TO220
transistors either side of the larger transformer?

The size of the output transformer looks more suited to 1 watt types.


I don't dispute that for a moment, but they *do* look like a pair of TO220
devices! There are no heatsinks so they are probably well under-run.

David.

[KeithR]

mick wrote:
On Tue, 15 Dec 2009 12:18:39 +0000, Jim Lesurf wrote:

In article , David Looser
wrote:
"Ian Bell" wrote
I had some of those too. There were also green spot rf ones. I still
have a red spot one. Must be worth a fortune now ;-)


If they are worth a fortune I'm sitting on a gold-mine here!
I think I have some old 'Newmarket' (if that was the name) transistors.
Maybe if these kinds of things are now 'historic relics' I should dig
some of them out... :-) IIRC they are still in the corrugated
cardboard in the boxes in which they were bought.



Would those be the ones in the flat cans with yellow & green spots for
audio and a red spot for RF, Jim?

Interesting page for flat cans:
http://homepages.nildram.co.uk/~wylie/NKT/newmarket.htm

Another for "top hat" cans:
http://homepages.nildram.co.uk/~wyli...an/Ediswan.htm

That is an interesting site, takes me back to being an apprentice lad at
RRE. I think that I have an STC "Crystal triode" kicking around somewhere,

[Arny Krueger]

"Jim Lesurf" wrote in message


I guess designers of commercial audio amps back then were
more habituated to using transformers than nowdays. I
didn't know about the above, but recall that some early
domestic transistor amps included things like coupling
transformers.

Driver transformers were last used in US built hifi amps, probably in the
origional Acoustic Research amplifier and receiver. Probably early 1970s.
It did not appear that they hindered performance all that much. It was a
pretty passable solution for building a SS amp in the days when
complementary transistors were expensive or simply unavailable.

http://www.hifiengine.com/manuals/ac...receiver.shtml .