Thanks for the info Adam. It doesn't really explain why the current is higher / sensitivity is lower for the IN-9. I still expect the IN9 to be brighter as the higher current should ionize more neon. Maybe I should measure it one day.
Michel On Thursday, November 29, 2012 8:25:31 AM UTC+11, Adam Jacobs wrote: > > I found this at radiomuseum.org: > <quote> > > At this point, I should clarify the difference between the IN-9 and the > IN-13 > > The IN-13 takes up to 5mA for a 12cm orange glow from Neon gas, and has > three electrodes. One perforated cylinder as the anode, a central wire > cathode for the glow, and a short pilot cathode to start the glow. > > Most IN-9 take up to 10mA for a 10cm purple glow from Argon gas, and only > have two electrodes. > > But some IN-9, like the one used in this thread, are filled with Neon gas > and glow orange, but the current rating and size are still same. > > Confusion between the two glow colors caused me to make a mistake I made > in this thread: The tube you see in this thread is a *2 pin IN-9*, not a > 3 pin IN-13. > > In terms of application of the tube, the two glow tubes the significant > differences are the maximum current and the extra pilot cathode for the > IN-13. The strike voltage around 120V and sustain voltage around 100V are > similar among all three tubes. > > The IN-13 has twice the sensitivity of the IN-9, so this should be taken > into account when applying the tube. If the glow swing is too extreme, some > resistance in series with the tube can be added. > > The pilot cathode of the IN-13 requires a small current to insure that the > main cathode starts properly. This negative bias could be obtained with a > 100-500kOhm resistor to the grid circuit of the local oscillator. The grid > of the local oscillator, usually develops around -10V, which is enough to > supply up to 100uA into the pilot cathode of the IN-13. > > The extra -10V of bias at the pilot cathode of the IN-13, eliminates the > need for the startup circuit with a diode and resistor, which I included in > the circuit above for the IN-9. This was necessary because the low B+ of an > AC/DC 117VAC radio may not guaranty the starting voltage for the two > terminal IN-9. > > Best regards, > > -Joe > </quote> > > -Adam > > On 11/28/2012 1:08 PM, Michel wrote: > > Just out of interest, is the IN-9 brighter than the IN-13? IN-9 requires > 10mA current for full bar and IN-13 4mA. Wondering where the extra 6mA goes > to, heat or light? > > Michel > > > On Tuesday, November 27, 2012 5:41:16 AM UTC+11, Dan Foster wrote: >> >> Hello, >> I have a few (10) IN-9 Bargraph tubes that I no longer want, thought I'd >> ask here before I list them on eBay. Anyone interested? > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To post to this group, send an email to neoni...@googlegroups.com<javascript:> > . > To unsubscribe from this group, send email to > neonixie-l+...@googlegroups.com <javascript:>. > To view this discussion on the web, visit > https://groups.google.com/d/msg/neonixie-l/-/tokUQ1-9DFMJ. > For more options, visit https://groups.google.com/groups/opt_out. > > > > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/9dhUW-PyGOwJ. For more options, visit https://groups.google.com/groups/opt_out.
