Arfa Daily wrote:

"Eeyore" wrote
Arfa Daily wrote:

Why does the heat from the anode of a power tube readily radiate across the
vacuum, but the heat from the filament of a vacuum light bulb seems not
to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's envelope
will take the skin off your fingertips after a few minutes use ...

What lighbulbs have *vacuums* in the bulb ? It's normally filled with a
non-reactive gas mixture.

Graham

"Eeyore" wrote in message
...


Arfa Daily wrote:

"Eeyore" wrote
Arfa Daily wrote:

Why does the heat from the anode of a power tube readily radiate
across the
vacuum, but the heat from the filament of a vacuum light bulb seems
not
to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's
envelope
will take the skin off your fingertips after a few minutes use ...

What lighbulbs have *vacuums* in the bulb ? It's normally filled with a
non-reactive gas mixture.

Graham


Maplins do a candle bulb that's vacuum filled. Also, see info on vacuum
bulbs at

http://members.misty.com/don/bulb1.html

Arfa

Arfa Daily wrote:

...snip...


Maplins do a candle bulb that's vacuum filled. Also, see info on vacuum
bulbs at

http://members.misty.com/don/bulb1.html

Arfa

"Vacuum filled," oh how I enjoy that one. It evokes the image of
someone pouring stuff form this bottle of "vacuum" into each
light bulb.

However, I do believe it might be a bit more proper to say the
bulbs are (or have been) evacuated. G

[ Sorry, the pedantic devil made me do this. ]


Later...

Ron Capik
--

Ron Capik wrote in
:

"Vacuum filled," oh how I enjoy that one. It evokes the image of
someone pouring stuff form this bottle of "vacuum" into each
light bulb.


Hell yes, and as we know that nature (allegedly) abhors a vaccuum, that
someone will really have to press the stuff in there hard.

"Ron Capik" wrote in message
...
Arfa Daily wrote:

...snip...


Maplins do a candle bulb that's vacuum filled. Also, see info on vacuum
bulbs at

http://members.misty.com/don/bulb1.html

Arfa

"Vacuum filled," oh how I enjoy that one. It evokes the image of
someone pouring stuff form this bottle of "vacuum" into each
light bulb.

However, I do believe it might be a bit more proper to say the
bulbs are (or have been) evacuated. G

[ Sorry, the pedantic devil made me do this. ]


Later...

Ron Capik
--


It's one of those 'odd ones' isn't it ? Obviously "filled" is not the right
word, and "evacuated" seems a bit 'scientific'. The references to these
bulbs tend to call them "vacuum filled", so I just went along with that ...
;-)

Arfa

Arfa Daily wrote:

"Ron Capik" wrote in message
...
Arfa Daily wrote:

...snip...


Maplins do a candle bulb that's vacuum filled. Also, see info on vacuum
bulbs at

http://members.misty.com/don/bulb1.html

Arfa

"Vacuum filled," oh how I enjoy that one. It evokes the image of
someone pouring stuff form this bottle of "vacuum" into each
light bulb.

However, I do believe it might be a bit more proper to say the
bulbs are (or have been) evacuated. G

[ Sorry, the pedantic devil made me do this. ]


Later...

Ron Capik
--


It's one of those 'odd ones' isn't it ? Obviously "filled" is not the right
word, and "evacuated" seems a bit 'scientific'. The references to these
bulbs tend to call them "vacuum filled", so I just went along with that ...
;-)

Arfa

Ahh, that so reminds me of the winning definition of "politically correct."
"" Political Correctness is a doctrine fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a
turd by the clean end.""

So do take care as to what end of the vacuum you fill with. G


Later...

Ron Capik
--

"Ron Capik" wrote in message
...
Arfa Daily wrote:

"Ron Capik" wrote in message
...
Arfa Daily wrote:

...snip...


Maplins do a candle bulb that's vacuum filled. Also, see info on
vacuum
bulbs at

http://members.misty.com/don/bulb1.html

Arfa

"Vacuum filled," oh how I enjoy that one. It evokes the image of
someone pouring stuff form this bottle of "vacuum" into each
light bulb.

However, I do believe it might be a bit more proper to say the
bulbs are (or have been) evacuated. G

[ Sorry, the pedantic devil made me do this. ]


Later...

Ron Capik
--


It's one of those 'odd ones' isn't it ? Obviously "filled" is not the
right
word, and "evacuated" seems a bit 'scientific'. The references to these
bulbs tend to call them "vacuum filled", so I just went along with that
...
;-)

Arfa

Ahh, that so reminds me of the winning definition of "politically
correct."
"" Political Correctness is a doctrine fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up
a
turd by the clean end.""

So do take care as to what end of the vacuum you fill with. G


Later...

Ron Capik
--

Yes, very amusing, but now the pedantic devil sitting on your shoulder, is
definitely asserting himself ... !!

Arfa

Ron Capik wrote:
"Vacuum filled," oh how I enjoy that one. It evokes the image of
someone pouring stuff form this bottle of "vacuum" into each
light bulb.

However, I do believe it might be a bit more proper to say the
bulbs are (or have been) evacuated. G

As long as you don't say something vacuous...

--
We can't possibly imprison 300 million Americans for not paying their
taxes, so let's grant all of them amnesty NOW!

On Wed, 27 Jun 2007 02:19:52 GMT, the renowned Eeyore
wrote:



Arfa Daily wrote:

"Eeyore" wrote
Arfa Daily wrote:

Why does the heat from the anode of a power tube readily radiate across the
vacuum, but the heat from the filament of a vacuum light bulb seems not
to? d;~}

Both do. It's called infra red radiation.

There's also conduction too.


Agreed that *should* be the case, but the fact is that the envelope of a
vacuum light bulb remains substantially cold in use, whilst a 6L6's envelope
will take the skin off your fingertips after a few minutes use ...

What lighbulbs have *vacuums* in the bulb ? It's normally filled with a
non-reactive gas mixture.

Graham

Many high voltage/low power bulbs are vacuum, IIRC. Don Klipstein says
break-even is 6-10W/cm of filament.

http://members.misty.com/don/bulb1.html


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Spehro Pefhany wrote in
:

http://members.misty.com/don/bulb1.html

That is such a good read I've seen bits of postings by him in the
LaserFAQ, but I never followed up enough to know how much good stuff he
wrote.