Prices will never go down. I bought some cheap tubes from TaoBao years ago (the SZ3-1 I started this post with and I think I paid $0.50 or so) but Chinese tubes are now expensive as well. Buy what you can buy now without looking at prices from 10 years ago. What you have will only increase in value because there's going to be less available every passing year. On Thursday, April 1, 2021 at 10:07:59 PM UTC+2 David Pye wrote:
> Please tell me there is a huge warehouse in China that will start selling > their stocks to bring the worldwide Nixie prices back down again! > > David > > > > > > > On Thu, 1 Apr 2021, 17:59 严泽远, <[email protected]> wrote: > >> There're over 17 different versions of Chinese QS30-1 tubes (SZ1-1, >> SZ3-1, SZ-8 are all same with QS30-1 but different brands), just curious >> which one you tested. >> Check the pictures here: https://www.nixieclock.org/?page_id=3162 >> >> [image: qs30-1.jpg] >> >> 在2021年4月1日星期四 UTC+8 上午7:26:11<David Pye> 写道： >> >>> Surely you've effectively got 10 of those resistors in parallel so the >>> tube current is 10x rated.... >>> >>> Poor old anode.... >>> >>> David >>> >>> On Wed, 31 Mar 2021, 23:02 Jon, <[email protected]> wrote: >>> >>>> You're putting AC across the tube? In addition to what Paul said, think >>>> about the scenario in the negative half-cycles. There you've got ten >>>> 'anodes' (the display digits, normally cathodes) each with their own >>>> resistor pouring current through one 'cathode' (the normal anode >>>> box/grid), >>>> which is definitely not sized for that current flow nor designed to have >>>> the glow on it bombarding its surface with lots of energetic particles. So >>>> all bets are off on tube behaviour in my view. >>>> >>>> In either polarity of the cycle, the common electrode might be seeing >>>> 22.5mA through it if your initial calculation holds. But very likely it >>>> doesn't, because that calculation assumes the normal tube maintaining >>>> voltage which I would have no confidence in being the case under these >>>> conditions. If the maintaining voltage drops significantly when the tube >>>> is >>>> run like this, then your current flow will be even more than you >>>> calculate. >>>> Maybe that's how you get to 9W. >>>> >>>> Ouch. Wouldn't bother putting that tube in a clock! >>>> >>>> Jon. >>>> >>>> >>>> On Wednesday, March 31, 2021 at 10:34:06 PM UTC+1 Paul Andrews wrote: >>>> >>>>> You should calculate the anode resistor you need for one segment. Use >>>>> that, then connect all the cathodes to ground. I have done this many >>>>> times >>>>> accidentally. Now the hand waving part: Imagine the connection between >>>>> the >>>>> anode and cathode is a resistor and you connect all of the cathodes >>>>> together - you are putting all of those resistors in parallel. You are >>>>> limiting the current on each one to 2.25mA, so you are pumping 22.5mA >>>>> through the one tube. I get that to be about 2W - (230-140)*0.0225. >>>>> >>>>> On Wednesday, March 31, 2021 at 4:11:49 PM UTC-4 gregebert wrote: >>>>> >>>>>> Very interesting; thanks for posting. >>>>>> >>>>>> You might want to try successive numbers of lit cathodes, say 01, >>>>>> then 012, then 0123, etc and see how the current increases, and also see >>>>>> if >>>>>> it changes over time due to heating. >>>>>> >>>>>> I dont recall seeing this behavior with segmented tubes, like the >>>>>> 7971. In fact, on my clock I have a current regulator on each cathode, >>>>>> and >>>>>> another one for the anode, for every tube.....that works out to 128 >>>>>> current >>>>>> regulators on that clock. >>>>>> >>>>>> On Wednesday, March 31, 2021 at 12:18:08 PM UTC-7 Bill van Dijk wrote: >>>>>> >>>>>>> Just a guess, but I think by lighting them all up you get some kind >>>>>>> of “super ionization” in the tube, which could then increase the >>>>>>> current >>>>>>> and heat dissipation. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Bill >>>>>>> >>>>>>> >>>>>>> >>>>>>> *From:* [email protected] [mailto:[email protected]] >>>>>>> *On Behalf Of *Yohan Park >>>>>>> *Sent:* Wednesday, March 31, 2021 3:15 PM >>>>>>> *To:* neonixie-l <[email protected]> >>>>>>> *Subject:* [neonixie-l] Lighting all digits at the same time: Why >>>>>>> does this happen? >>>>>>> >>>>>>> >>>>>>> >>>>>>> I have a few Chinese QS30-1 tubes lying around which don't have much >>>>>>> value for me and was wondering how it would look to have all digits lit >>>>>>> at >>>>>>> the same time. >>>>>>> So I looked up the specs which say 170V and 2.25mA >>>>>>> So I calculated the needed resistor to have it hooked up to 230V >>>>>>> which is a little below 27K >>>>>>> I then connected a 27K resistor to one cathode and it lit perfectly >>>>>>> fine (230V AC so the anode also glows). >>>>>>> So I then connected 10x 27K resistors to all the cathodes and >>>>>>> plugged it in. >>>>>>> Holy Moly! The thing lit up like crazy and was drawing over 9 Watts >>>>>>> and was getting VERY hot. So I turned it off again after a few seconds. >>>>>>> Can anyone tell why it's behaving like that? >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "neonixie-l" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to [email protected]. >>>>>>> To view this discussion on the web, visit >>>>>>> https://groups.google.com/d/msgid/neonixie-l/bffb114c-9810-4d65-8e98-ee13f6c860fcn%40googlegroups.com >>>>>>> >>>>>>> <https://groups.google.com/d/msgid/neonixie-l/bffb114c-9810-4d65-8e98-ee13f6c860fcn%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "neonixie-l" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> >>> To view this discussion on the web, visit >>>> https://groups.google.com/d/msgid/neonixie-l/c8c35a61-fa0a-4249-9311-47061c50865cn%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/neonixie-l/c8c35a61-fa0a-4249-9311-47061c50865cn%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/12ad2419-424c-4b08-a58a-074901cb4bf8n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/12ad2419-424c-4b08-a58a-074901cb4bf8n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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