"Brian Gaff" wrote in message
news
Its purely because of mass production of course. once the main factories
making valves got below a certain number prices started going up, and vice
versa for semiconductors of course.
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.


Well, I must have been leading a *charmed life* all these years and didn't
know it!!

First, I have never had anything like the 'normal failure rate' in vinyl
that others appear to have experienced and, to top that, I have never had
any problems with a variety of Chinese valves that have passed through my
hands - that's no problems whatsoever, AFAICR...??

CF2 miniature pentode/triode input valves were indistinguishable from
Mullard EC82 (?) replacements; Shuguan EL34 and various Chinese 300B output
valves all worked and sounded perfectly fine - including Golden Dragons
branded 'Audio Note' and 'Chelmer'!

Pity I can't have the same luck with lottery tickets!

@:-)


(In fact, I'd go as far as to say that all my valve and rectifier failures
have beeen Russian and whatever JJ Tesla is!!??)

"Keith G"


CF2 miniature pentode/triode input valves were indistinguishable from
Mullard EC82 (?) replacements; Shuguan EL34 and various Chinese 300B
output valves all worked and sounded perfectly fine - including Golden
Dragons branded 'Audio Note' and 'Chelmer'!


Streuth, that reminds me it's Christmas time again - here's a pic of my
miniatures off on their Christmas Holidays a few years ago!

http://www.moirac.adsl24.co.uk/showntell/Holidays.jpg


And I'm wondering now if I didn't have a Chinese rectifier valve go pop on
me....??

On Dec 14, 4:12*pm, "Keith G" wrote:

And I'm wondering now if I didn't have a Chinese rectifier valve go pop on
me....??

Going *POP* on you is the least of your worries. It is when they melt
into a puddle with the subsequent down-line damage.

I do not stray far from Chinese 5AR4s - and I do keep two for bench
testing purposes.

Peter Wieck
Melrose Park, PA

Peter Wieck wrote:
On Dec 14, 4:12 pm, "Keith G" wrote:

And I'm wondering now if I didn't have a Chinese rectifier valve go pop on
me....??

Going *POP* on you is the least of your worries. It is when they melt
into a puddle with the subsequent down-line damage.

I do not stray far from Chinese 5AR4s - and I do keep two for bench
testing purposes.

When you say 'bench testing' do you men testing the bench against molten
glass?

Cheers

ian

Peter Wieck
Melrose Park, PA

On Dec 14, 5:15*pm, Ian Bell wrote:

When you say 'bench testing' do you men testing the bench against molten
glass?

Haven't reached that much heat yet - These tubes tend to slag inside
when they fail.

I was given two Chinese 5AR4s as throw-ins with an amp I purchased -
so I keep them for testing 5AR4-based equipment. Right where I can
keep an eye on them and I do not put any good tubes at risk. I am
slowly moving over to SS 5AR4s. The cost for a good slow-start-
mimicking SS 5AR4 is about what I can pay for a NIB/NOS US-made glass
unit so far ($25 or so), but the insane prices I am seeing on eBay has
me re-thinking putting glass units in equipment that has no particular
need for authenticity. And the dozen or so such units I have in my
stock may make a nice retirement nest egg.

Peter Wieck
Melrose Park, PA

In article ,
Don Pearce wrote:
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.

Prices of transistors were dropping rapidly even then. I paid 7/6 for a
red spot (OC71 reject) in '59.

--
*Reality? Is that where the pizza delivery guy comes from?

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

"Ian Bell" wrote in message
...
Don Pearce wrote:
On Mon, 14 Dec 2009 09:19:10 -0800 (PST), Engineer
wrote:

On Dec 14, 10:23 am, "David Looser"
wrote:
"Ian Bell" wrote in message

...

Don Pearce wrote:
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.
d
I have some WW from 1940 to 46 - I'll see if I can find a camparison
page.
Valve prices didn't change much in money terms between the 1930s and
the
1960s. There might have been a slight reduction, but not a lot. Of
course
inflation was low during that time too. Transistors on the other hand
dropped dramatically in price and carried on doing so for a long time.
An
article I have from a 1952 edition of 'Radio Constructor' refers to
"some
(transistors) the writer recently obtained from the USA cost almost as
much
as a miniature receiver". Whilst these days a bag of 100 BC548s costs
but a
few pennies each.

David.

Ian
Way, way back, I nearly cried when I fried an OC71 in an audio stage I
was trying to make!

They were down to 5 Bob by 1966 - absolute bargain, particularly when
you scraped the paint off and used them for a photo transistor. I
first discovered this by accident when an amplifier I had made hummed
when I took the hardboard cover off the back.

d

And then a few years later they filled them with some opaque goop so you
couldn't and sold clear ones as the OCP71 at a much higher price -
*******s!

Cheers

ian
But if you were really mean, you could carefully hacksaw or file off the
envelope leaving the semiconductor exposed, then clean off the gloop with
meths. You then put back the now clean and scraped off cover, and wrapped a
bit of sticky tape round the join. Voila, at least ten bob saved, albeit at
the cost of three hours work!

Oh how we laughed....

S.

Brian said:

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.

Chinese valves haven't all been bad, although most made in
large quantities have been.

I notice Watford Valves, possibly the biggest UK retailer,
refused to sell Chinese valves on grounds of quality up
until recently. Now they offer quite a few.

If anyone's got their finger on the pulse, I wonder how well
Chinese valves are respected these days?

Ian

"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

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.
--
Ian