I suggest applying a lower potential, say 4 Volts. That would make the glow
a more orange color, maybe more impressive, without risk to the filament and
a lower bulb temperature.

On the other hand, are you sure this tube is defective? Good tubes are
worth around $100 and I'm sure you can find a shorted one for very little.

Due to the high current drawn by the filament, it's common for a poor socket
contact to cause excessive heat at the tube pin, melting the solder and
causing the filament to go out. There are many tubes out there that have
been scrapped with the thought that the filament is burned out, when in fact
the tubes are repairable. (I just repaired one for a fellow amateur.)

Bob

Add a couple of blue ones for a "gas" effect!

Harvey White wrote:

On Fri, 19 Sep 2003 02:03:12 -0500, Scott Schrader
wrote:



isn't that going to get it hot enough in time to crack the seals? had
some guys working up a linear in 1971 at NDSU that just had the
filaments on a pair of 4-400s without the fan on, and killed 'em with an
ugly, loud cracking noise.

orange LEDs would be more authentic, I think, than red ones to make a
glow in the firebottle.



I like the LED idea, you'd want some bright ones....

Harvey








--
Joe Leikhim K4SAT


"Jazz is not dead. It just smells funny." -F.Z.

Add a couple of blue ones for a "gas" effect!

Harvey White wrote:

On Fri, 19 Sep 2003 02:03:12 -0500, Scott Schrader
wrote:



isn't that going to get it hot enough in time to crack the seals? had
some guys working up a linear in 1971 at NDSU that just had the
filaments on a pair of 4-400s without the fan on, and killed 'em with an
ugly, loud cracking noise.

orange LEDs would be more authentic, I think, than red ones to make a
glow in the firebottle.



I like the LED idea, you'd want some bright ones....

Harvey








--
Joe Leikhim K4SAT


"Jazz is not dead. It just smells funny." -F.Z.

On Sat, 20 Sep 2003 00:59:36 -0400, **THE-RFI-EMI-GUY**
wrote:

Add a couple of blue ones for a "gas" effect!

Now if you add a few flashing white ones, you have the "intermittent
short" effect....

Harvey


Harvey White wrote:

On Fri, 19 Sep 2003 02:03:12 -0500, Scott Schrader
wrote:



isn't that going to get it hot enough in time to crack the seals? had
some guys working up a linear in 1971 at NDSU that just had the
filaments on a pair of 4-400s without the fan on, and killed 'em with an
ugly, loud cracking noise.

orange LEDs would be more authentic, I think, than red ones to make a
glow in the firebottle.



I like the LED idea, you'd want some bright ones....

Harvey

On Sat, 20 Sep 2003 00:59:36 -0400, **THE-RFI-EMI-GUY**
wrote:

Add a couple of blue ones for a "gas" effect!

Now if you add a few flashing white ones, you have the "intermittent
short" effect....

Harvey


Harvey White wrote:

On Fri, 19 Sep 2003 02:03:12 -0500, Scott Schrader
wrote:



isn't that going to get it hot enough in time to crack the seals? had
some guys working up a linear in 1971 at NDSU that just had the
filaments on a pair of 4-400s without the fan on, and killed 'em with an
ugly, loud cracking noise.

orange LEDs would be more authentic, I think, than red ones to make a
glow in the firebottle.



I like the LED idea, you'd want some bright ones....

Harvey

"Harvey White" wrote in message
...
On Sat, 20 Sep 2003 00:59:36 -0400, **THE-RFI-EMI-GUY**
wrote:

Add a couple of blue ones for a "gas" effect!

Now if you add a few flashing white ones, you have the "intermittent
short" effect....

Harvey


Harvey White wrote:

On Fri, 19 Sep 2003 02:03:12 -0500, Scott Schrader
wrote:



isn't that going to get it hot enough in time to crack the seals? had
some guys working up a linear in 1971 at NDSU that just had the
filaments on a pair of 4-400s without the fan on, and killed 'em with
an
ugly, loud cracking noise.

orange LEDs would be more authentic, I think, than red ones to make a
glow in the firebottle.



I like the LED idea, you'd want some bright ones....

Harvey








Or you could modulate the led's in sync with your voice when your on the
air. Sorta like a 250TH in AM mode.

Dan/W4NTI

"Harvey White" wrote in message
...
On Sat, 20 Sep 2003 00:59:36 -0400, **THE-RFI-EMI-GUY**
wrote:

Add a couple of blue ones for a "gas" effect!

Now if you add a few flashing white ones, you have the "intermittent
short" effect....

Harvey


Harvey White wrote:

On Fri, 19 Sep 2003 02:03:12 -0500, Scott Schrader
wrote:



isn't that going to get it hot enough in time to crack the seals? had
some guys working up a linear in 1971 at NDSU that just had the
filaments on a pair of 4-400s without the fan on, and killed 'em with
an
ugly, loud cracking noise.

orange LEDs would be more authentic, I think, than red ones to make a
glow in the firebottle.



I like the LED idea, you'd want some bright ones....

Harvey








Or you could modulate the led's in sync with your voice when your on the
air. Sorta like a 250TH in AM mode.

Dan/W4NTI

On Sun, 21 Sep 2003 15:58:29 GMT, "Dan/W4NTI" w4nti@get rid of this
mindspring.com wrote:

Or you could modulate the led's in sync with your voice when your on the
air. Sorta like a 250TH in AM mode.

How about key down lights it up as well... Then you can explain how
you are putting out so much power.....

Harvey

Dan/W4NTI

On Sun, 21 Sep 2003 15:58:29 GMT, "Dan/W4NTI" w4nti@get rid of this
mindspring.com wrote:

Or you could modulate the led's in sync with your voice when your on the
air. Sorta like a 250TH in AM mode.

How about key down lights it up as well... Then you can explain how
you are putting out so much power.....

Harvey

Dan/W4NTI

Also I know it is a 5 volt tube
and 14.5 amp.do I really need that much to make it glow? Would 12 volt
work?
======
Having a 5 volts filament ,requiring 14.5 Amperes ,would make it a nice 70 +
Watts (anti-condensation) heater.

Applying 12V would turn it in a 'RIP state' within a few seconds.

Frank GM0CSZ / KN6WH