IN-9 Neon Bargraph for tube amplifier

[Tubekwk]

I was looking at YouTube videos and discovered the IN-9 neon analogue bargraph that is current driven 0 to 18mA at around 110 volts.

One could make a sand free light display for a tube amplifier or preamp, possibly driving them with pentodes as the high plate resistance would be favourable. Easy to spice up a V to I drive using tubes.
Has anyone tried them?

Lovely IN-9 Bargraph nixie tube VU level meter ,Spectrum Analyzer - YouTube

NIEXIE audio spectrum analyser on IN-9 tubes - YouTube


IN-9 IN9 neon Nixie tube bargraph Indicator linear signal meter NEW | eBay

 

[duncan2]

Neon ?--it must have improved its gaseous composition as it is a noise producer and you are going to use them in an---audio amplifier ?


As I am used to their "effect " in radio communications I hope in this modern day and age somebody is going to say " neon?--- no problem now with "modern techniques" ??


Checking on upmarket electronic engineers websites it seems its "okay " as a power supply indicator on a front panel but definitely not as a circuit part of a quality audio amplifier.

 

[kodabmx]

It's used as a level meter Why is noise an issue if it's not part of the audio output but just driven by a buffer? I use a VR75 shunt regulator for my bias supply - no noise added by it that I can measure.

Someone makes a spectrum analyzer with them... EN IN-9 Nixielyzer

There's a longer one called IN-13, too... https://cdn.instructables.com/ORIG/FBL/OC7A/JVH3KWJ2/FBLOC7AJVH3KWJ2.pdf

 

[gideon1990]

IN-13 is preferential because the auxiliary electrode ensures they ignite at the bottom

 

[duncan2]

Quote- why is it an issue ?- neon indicators/lamps electrodes are made from thoriated steel ( or somewhat like matter - Americium ) that is long life radioactive to stimulate emission from the cold cathode --the EU didn't like that --radio active .

 

[Tubekwk]

I've had a search and found no actual data on the conducted and radiated EMI from these devices. Has any member of this forum any data on the subject or first hand experience with these devices?

 

[Tubekwk]

Quote- why is it an issue ?- neon indicators/lamps electrodes are made from thoriated steel ( or somewhat like matter - Americium ) that is long life radioactive to stimulate emission from the cold cathode --the EU didn't like that --radio active .

Thank you for the post duncan2.

Thorium! I'm surrounded by the stuff 🙂, I have some old thorium gas mantles and some tungsten/thorium TIG welding electrodes used for testing my Geiger counters. Are the thoriated tungsten cathodes in transmitting tubes very radioactive? If I happen to break one I will have a sniff with a Geiger counter.

Americium, still have a few of the old style smoke detectors about, changing to Photoelectric types, last century when at school I remember our science teacher found a tube with a unipotential cathode that set a Geiger counter clicking, apparently some cathode coatings were mildly radioactive.

Are Welding Rods Radioactive? – WeldingBoss.com.

 

[astouffer]

Neon devices should be pretty quiet. In the power supply forum there was a thread about noise and the neon reference tubes were more quiet than a lot of silicon.