hi since i am fairly clueless about ss components i am wondering is there a thermister that would slowly drop res. over a period of time say 10 or 15 seconds instead of just a second or so?i am trying to get a ne2 lamp to slowly light like a tube filament on the b+ current.i need some device without a circut which causes rf noise.butch

There is no way to gradually light a neon. It has no filament to warm up. The gas between the electrodes "fires" suddenly and glows at about 70 volts. You can make it brighter (just a bit) by raising the voltage, but if you put too much voltage on it, it will overheat and burn up.

I use orange LEDs to simulate tube filaments. You can connect a capacitor (large electrolytic) across the LED and it will take a few seconds for the LED to come to full brightness. The larger the capacitor, the longer the time delay.

Rich
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:hi since i am fairly clueless about ss components i am wondering is there a thermister that would slowly drop res. over a period of time say 10 or 15 seconds instead of just a second or so?i am trying to get a ne2 lamp to slowly light like a tube filament on the b+ current.i need some device without a circut which causes rf noise.butch

:There is no way to gradually light a neon. It has no filament to warm up. The gas between the electrodes "fires" suddenly and glows at about 70 volts. You can make it brighter (just a bit) by raising the voltage, but if you put too much voltage on it, it will overheat and burn up.
:
:I use orange LEDs to simulate tube filaments. You can connect a capacitor (large electrolytic) across the LED and it will take a few seconds for the LED to come to full brightness. The larger the capacitor, the longer the time delay.
:
:Rich
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::hi since i am fairly clueless about ss components i am wondering is there a thermister that would slowly drop res. over a period of time say 10 or 15 seconds instead of just a second or so?i am trying to get a ne2 lamp to slowly light like a tube filament on the b+ current.i need some device without a circut which causes rf noise.butch
hi and thanks for the reply rich i should have known that as i have a rca farm radio with a neon- cap hookup which causes the bulb to blink every time the cap charges but as you say it just flashes there's no gradual increase in brightness.what i was trying to acomplish was as follows.i had a set with a bad xformer i didn't have another one with a 5 v. tap for the rectifier tube so i put 2 1n4007 diodes in a tube base and bridged the 2 with a ne2 and a 1 meg. res. then i cut off a glass tube envelope and glued it in the base so it resembled a tube glowing looking at this thing i thought could i put a time delay switch in the center tap of the b+ so it warmed up slowly like a tube so if cathode stripping actually occurs this might help and the indicater bulb would show the time delay.i guess i didn't think this though very well it now seems like an awfull lot of trouble when i could have found the right xformer and used a 5y3 tube i must be related to rube goldberg. butch

I also like to make "tube look-alikes." I tried cutting the glass envelope from an old tube, but the edge chipped badly. I used a Dremel tool and carbide wheel with water to cool it. Kinda messy. I have made some modern "tubes" with acrylic tubing. I've made a functional 5U4 and my version of a 6L6, which actually contains a modern LM386 audio amplifier chip, all the capacitors, and a voltage regulator. I used an orange LED for the filament, but didn't try to build-in a warm-up delay... maybe next time I build one, I will try it. Needs a big capacitor for the RC network to create the delay. You can actually get some range of brightness from LEDs. Most will glow at about 3 or 5 mA and can be run up to 20 or 30 mA at hi brightness.
Rich

::There is no way to gradually light a neon. It has no filament to warm up. The gas between the electrodes "fires" suddenly and glows at about 70 volts. You can make it brighter (just a bit) by raising the voltage, but if you put too much voltage on it, it will overheat and burn up.
::
::I use orange LEDs to simulate tube filaments. You can connect a capacitor (large electrolytic) across the LED and it will take a few seconds for the LED to come to full brightness. The larger the capacitor, the longer the time delay.
::
::Rich
::%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
::
:::hi since i am fairly clueless about ss components i am wondering is there a thermister that would slowly drop res. over a period of time say 10 or 15 seconds instead of just a second or so?i am trying to get a ne2 lamp to slowly light like a tube filament on the b+ current.i need some device without a circut which causes rf noise.butch
:hi and thanks for the reply rich i should have known that as i have a rca farm radio with a neon- cap hookup which causes the bulb to blink every time the cap charges but as you say it just flashes there's no gradual increase in brightness.what i was trying to acomplish was as follows.i had a set with a bad xformer i didn't have another one with a 5 v. tap for the rectifier tube so i put 2 1n4007 diodes in a tube base and bridged the 2 with a ne2 and a 1 meg. res. then i cut off a glass tube envelope and glued it in the base so it resembled a tube glowing looking at this thing i thought could i put a time delay switch in the center tap of the b+ so it warmed up slowly like a tube so if cathode stripping actually occurs this might help and the indicater bulb would show the time delay.i guess i didn't think this though very well it now seems like an awfull lot of trouble when i could have found the right xformer and used a 5y3 tube i must be related to rube goldberg. butch

:I also like to make "tube look-alikes." I tried cutting the glass envelope from an old tube, but the edge chipped badly. I used a Dremel tool and carbide wheel with water to cool it. Kinda messy. I have made some modern "tubes" with acrylic tubing. I've made a functional 5U4 and my version of a 6L6, which actually contains a modern LM386 audio amplifier chip, all the capacitors, and a voltage regulator. I used an orange LED for the filament, but didn't try to build-in a warm-up delay... maybe next time I build one, I will try it. Needs a big capacitor for the RC network to create the delay. You can actually get some range of brightness from LEDs. Most will glow at about 3 or 5 mA and can be run up to 20 or 30 mA at hi brightness.
:Rich
:
:
:::There is no way to gradually light a neon. It has no filament to warm up. The gas between the electrodes "fires" suddenly and glows at about 70 volts. You can make it brighter (just a bit) by raising the voltage, but if you put too much voltage on it, it will overheat and burn up.
:::
:::I use orange LEDs to simulate tube filaments. You can connect a capacitor (large electrolytic) across the LED and it will take a few seconds for the LED to come to full brightness. The larger the capacitor, the longer the time delay.
:::
:::Rich
:::%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
:::
::::hi since i am fairly clueless about ss components i am wondering is there a thermister that would slowly drop res. over a period of time say 10 or 15 seconds instead of just a second or so?i am trying to get a ne2 lamp to slowly light like a tube filament on the b+ current.i need some device without a circut which causes rf noise.butch
::hi and thanks for the reply rich i should have known that as i have a rca farm radio with a neon- cap hookup which causes the bulb to blink every time the cap charges but as you say it just flashes there's no gradual increase in brightness.what i was trying to acomplish was as follows.i had a set with a bad xformer i didn't have another one with a 5 v. tap for the rectifier tube so i put 2 1n4007 diodes in a tube base and bridged the 2 with a ne2 and a 1 meg. res. then i cut off a glass tube envelope and glued it in the base so it resembled a tube glowing looking at this thing i thought could i put a time delay switch in the center tap of the b+ so it warmed up slowly like a tube so if cathode stripping actually occurs this might help and the indicater bulb would show the time delay.i guess i didn't think this though very well it now seems like an awfull lot of trouble when i could have found the right xformer and used a 5y3 tube i must be related to rube goldberg. butch

i cut the tubes off the same way i put a valve in a plastic jug mounted on a stand which i use to dribble water on the tube then i use a dremel with one of those diamond cut off wheels you get from harbor freight it usally works well but sometimes they crack i've been going to try a cordless dremel i have as it runs much slower and should'nt build up as much heat some of the balloon and st tubes are hard to get the guts out of though, its kind of like ship in the bottle time.butch