W8CRZ wrote:
I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with.

Pins 1 and 5.

Also I know it is a 5 volt tube
and 14.5 amp.do I really need that much to make it glow?

Yes, you do.

Would 12 volt work?

For a very, very limited time, providing your 12V supply is capable of
dishing out 40A. If it's not, it would either clamp down to the maximum
current or trip the breaker.

If all you want to do is make it appear that it's glowing, build in a
few LEDs into the wood base. None will be the wiser.


73 .... WA7AA


--

Anti-spam measu look me up on qrz.com if you need to reply directly

W8CRZ wrote:
I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with.

Pins 1 and 5.

Also I know it is a 5 volt tube
and 14.5 amp.do I really need that much to make it glow?

Yes, you do.

Would 12 volt work?

For a very, very limited time, providing your 12V supply is capable of
dishing out 40A. If it's not, it would either clamp down to the maximum
current or trip the breaker.

If all you want to do is make it appear that it's glowing, build in a
few LEDs into the wood base. None will be the wiser.


73 .... WA7AA


--

Anti-spam measu look me up on qrz.com if you need to reply directly

I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with. 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?
Thanks
Rob W8CRZ

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.

Dick Carroll wrote:

W8CRZ wrote:

I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with. 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?
Thanks
Rob W8CRZ

You sure don't want to put 12 volts on it unless you want to burn out the
filament. It needs 5 volts. The transformer will have to supply the 14.5 amps or
it will not hold up, either. There are 5 volt transformers out there which have
no center tap that can be bought pretty cheap since they won't work out easily
for use in an amplfier..

Dick

-- If it's a "new economy," why do they want my obsolete old money?

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.

Dick Carroll wrote:

W8CRZ wrote:

I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with. 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?
Thanks
Rob W8CRZ

You sure don't want to put 12 volts on it unless you want to burn out the
filament. It needs 5 volts. The transformer will have to supply the 14.5 amps or
it will not hold up, either. There are 5 volt transformers out there which have
no center tap that can be bought pretty cheap since they won't work out easily
for use in an amplfier..

Dick

-- If it's a "new economy," why do they want my obsolete old money?

On Fri, 19 Sep 2003 04:49:56 GMT, "W8CRZ" wrote:

I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with. 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?

12 volts will burn out the filament.

You might be able to try less than that. However, try an old computer
power supply, they should be able to give you either 3.3 volts at a
lot of amps, or 5 volts at a lot of amps.... I'd try the 3.3 volts
first, since you want a gentle glow, not the full filament.

Harvey


Thanks
Rob W8CRZ

On Fri, 19 Sep 2003 04:49:56 GMT, "W8CRZ" wrote:

I have a 3-500z tube and just want to make a conversation piece out of it. I
am going to make a wood base for it and I would also like to feed some
current into it just to make it glow.I was told it was possible but he
wasn't sure how or which pins to do it with. 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?

12 volts will burn out the filament.

You might be able to try less than that. However, try an old computer
power supply, they should be able to give you either 3.3 volts at a
lot of amps, or 5 volts at a lot of amps.... I'd try the 3.3 volts
first, since you want a gentle glow, not the full filament.

Harvey


Thanks
Rob W8CRZ

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 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

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