Pete I'd appreciate a copy of your schematics and board layout. I have a couple of hundred XC18s in the cupboard that I want to turn into a "reliable" clock and would be interested to see you layout.
Kind regards Michael On Wednesday, 16 May 2012 19:04:56 UTC+10, petehand wrote: > > I built an XC18 clock based on Graham's design and can confirm, > disappointingly, it won't work in the dark. I heard from an old friend > of my father's, who used to work for Hivac, that these tubes were made > with a small amount of radioactive material to assist with > ionization, and presumably it's had enough half lives by now to be > ineffective. > > If anyone is interested, I will email them a copy of my schematics, > which are closely similar to Graham's. I also have one spare PCB - I > did the whole thing (less the power supply) on a single board ten > inches by seven. > > Pete Hand > > > On May 9, 12:10 pm, Dylan Distasio <[email protected]> wrote: > > Thanks for the info and comments, Grahame. As an aside, I love your > clock, > > and your other interesting projects! > > > > I'll take a look at the book. If you wouldn't mind emailing me the > design, > > that would be great also. > > > > I will definitely take you up on your offer for continued correspondence > as > > I move forward. > > > > Best, > > Dylan > > > > On Wed, May 9, 2012 at 2:16 PM, Grahame Marsh > > <[email protected]>wrote: > > > > > > > > > > > > > > > > > Dylan, > > > > > The main design flaw with the published trigger tube clock is the > change > > > of supply voltage (I frigged the anode resistor to compensate). This > does > > > effect the pulse carry timing considerably. The main problem with > the > > > XC18 is it requires light to trigger reliably - leave the clock in a > dark > > > room and one or more rings will have failed by the morning. Tubes > with a > > > keep alive electrode like the Z700U will operate in complete darkness. > My > > > own XC18 clock is now just a demonstration clock that I fire up just > to > > > show it off as and when. > > > > > I have a design for a second XC18 clock with schematics and layouts > done > > > in Eagle which I can email to you if you want to see them? This will > give > > > you a (all valve) design of a stabilised PSU and a 50 (or 60) Hz to 1 > Hz > > > divider using a two stage phantasmagorical divider which has a pulse > shaper > > > at the end to drive a XC18. > > > > > For a more back-to-basics on trigger tube circuit design then download > > > this book by Neale (86MB) chapter 5 in particular: > > > > >http://www.sgitheach.org.uk/**dmneale.pdf< > http://www.sgitheach.org.uk/dmneale.pdf> > > > > > As it goes through the design process for trigger tubes (it uses the > Z700U > > > in the worked example). > > > > > As a general comment to anyone on the list it is an ebook worth having > > > IMHO. > > > > > Building dividers on a breadboard is very easy and work well. The > first > > > divider I built was a two tube, divide by two, and then I added > several > > > more stages just to watch it count. I used a simple neon relaxtion > > > oscillator to provide a slow enough tick that the dividers could be > seen to > > > be working rather than just using a 'scope. > > > > > There are other XC18 clocks out there but all have the same darkness > > > problem so must be kept lit. A few UV leds seem to work fine but the > holy > > > grail of an all valve clock has perhaps then been lost. > > > > > The clock web page now lives on my own website as well > > > > >http://www.sgitheach.org.uk/**nixie3.html< > http://www.sgitheach.org.uk/nixie3.html> > > > > > Happy to correspond, and I'm sure others will have comments as well. > > > > > Cheers Grahame > > > > > On 09/05/2012 18:32, Dylan Distasio wrote: > > > > >> Hi all- > > > > >> I recently picked up some XC18 trigger tubes in the hope of > eventually > > >> building a trigger tube clock inspired by Grahame's work > > >>http://www.neonixie.com/**trigger-tube-clock/Trigger_**Clock.pdf< > http://www.neonixie.com/trigger-tube-clock/Trigger_Clock.pdf> > > >> . > > > > >> I have reviewed some of the basic trigger tube circuits out there, > but > > >> was hoping someone with experience using trigger tubes could provide > some > > >> additional guidance. > > > > >> I am interested in building a simple ring counter circuit on a > breadboard > > >> but wasn't sure what resistor / capacitor values to use, and an input > for > > >> the trigger. I will probably eventually use the mains frequency in > the > > >> clock, but am open to suggestions on another source for testing. Any > help > > >> on the simplest possible ring counter circuit possible with these > tubes and > > >> other tips would be greatly appreciated. > > > > >> Thanks, > > >> Dylan > > >> -- > > >> You received this message because you are subscribed to the Google > Groups > > >> "neonixie-l" group. > > >> To post to this group, send an email to [email protected]. > > >> To unsubscribe from this group, send email to > neonixie-l+unsubscribe@** > > >> googlegroups.com <neonixie-l%[email protected]>. > > >> For more options, visit this group athttp://groups.google.com/** > > >> group/neonixie-l?hl=en-GB< > http://groups.google.com/group/neonixie-l?hl=en-GB> > > >> . > > > > > -- > > > You received this message because you are subscribed to the Google > Groups > > > "neonixie-l" group. > > > To post to this group, send an email to [email protected]. > > > To unsubscribe from this group, send email to > neonixie-l+unsubscribe@** > > > googlegroups.com <neonixie-l%[email protected]>. > > > For more options, visit this group athttp://groups.google.com/** > > > group/neonixie-l?hl=en-GB< > http://groups.google.com/group/neonixie-l?hl=en-GB> > > > . -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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