[Milsurplus] Query

[jfor at quik.com]

Of course you could. The heat loss from a filament is by conduction
through the leads, which would be unchanged, convection, which is
essentially zero, and radiation. The only material influence would be the
loss of heat to the filament from radiation back to the filament from the
envelope, and that's essentially trivial.

-John




> Hi Pete, Jim and all,
>
> Yes, interesting thought, operating a vacuum tube in the vacuum of space.
> But consider the temperature in space and what it would do to the
> elements.
> Could you even light the filament?
> Now that's a cold 807!
> 73, David W1TDD
>
> ----- Original Message -----
> From: "Jim Haynes" <jhhaynes at earthlink.net>
> To: "Pete Williams" <jupete at bigpond.net.au>
> Cc: <milsurplus at mailman.qth.net>
> Sent: Tuesday, March 11, 2008 10:58 PM
> Subject: Re: [Milsurplus] Query
>
>
>>I don't know the answer, but that reminded me that back in my student
>> days some 50 years ago, when the Space Age was just starting, we used
>> to imagine you could operate vacuum tubes in space without any glass
>> bulb.