Well yes, the heat generation alone fo valves made it pretty hard to make
small items run cool.
I have some old 405line projection tubes somewhere. Never run one outside
the light box with its 1inch thick lead glass concave mirror or you will
get an Xray overdose!
Brian

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"Bob Eld" wrote in message
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"David Looser" wrote in message
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"Ian Bell" wrote in message
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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

How about 450,000 transistors for $50 in a processor. That's $0.00011 per!
That level of integration makes our modern computerized world possible.
Imagine trying to do it with "fire bottles"!

"Brian Gaff" wrote in message
om...


I have some old 405line projection tubes somewhere. Never run one outside
the light box with its 1inch thick lead glass concave mirror or you will
get an Xray overdose!


You mean the Mullard MW6-2?

Not specific to 405-lines of course, it was widely used on the continent in
625-line and even some French 819-line sets.

It ran with 25kV on the final anode, same as a modern colour tube, but
without the lead glass of the colour tube.

David.