On 5/19/2016 6:59 PM, Joe Croft wrote:
It's hell being dyslexic! I have the tubes wired backwards :( What is amazing is how they lit up and seem to work fine besides the issue of drawing 3 times as much current they should.Sigh... Off to add lots of cuts and jumpers too my board! -joeOn Thu, May 19, 2016 at 5:32 PM, Joe Croft <[email protected] <mailto:[email protected]>> wrote:I do seem to have a problem with my board. I have pulled one of the tubes and just tried it on a bread board and life is good. Though in the board, not so good. I will have to dig harder on the layout. Something is just not right. -joe On Thu, May 19, 2016 at 2:59 PM, gregebert <[email protected] <mailto:[email protected]>> wrote: Best thing to do is gather data for several tubes, and plot it. Inconsistent data suggests problems with the tubes; maybe they are used, out-of-spec, reject, etc units. I would use a voltmeter and measure the voltage at the following locations, while adjusting Vc to obtain (a) First speckle of light on the tube, (b) 25%, (c) 50%, (d) 75%, (e) maximum, which might not be 100%. Measure Vc, Voltage at emitter, voltage at collector, voltage at the AUX pin, AND the +120V supply (it may not be constant, due to loading). Obviously you would enter this data into a spreadsheet because there are calculations that need to be done (tube voltage and current), and it does a good job creating plots. Once you have that info, we can figure out what's going on. Is the transistor getting warm ? Depending upon the case style it may only be capable of 625mW. >From the circuit, I can see scenarios where you could exceed this if you're running at 160V and above 13mA.-- You received this message because you are subscribed to theGoogle Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <mailto:[email protected]>. To post to this group, send email to [email protected] <mailto:[email protected]>. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/b6cbe906-453b-4e5b-8062-2c80848ba8df%40googlegroups.com <https://groups.google.com/d/msgid/neonixie-l/b6cbe906-453b-4e5b-8062-2c80848ba8df%40googlegroups.com?utm_medium=email&utm_source=footer>. For more options, visit https://groups.google.com/d/optout. --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] <mailto:[email protected]>. To post to this group, send email to [email protected] <mailto:[email protected]>. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAE%2BVk6OhRLRy27_Sf3fEXT5VZJ8hVYSbZoVTXcun1FeDtb2%3D9w%40mail.gmail.com <https://groups.google.com/d/msgid/neonixie-l/CAE%2BVk6OhRLRy27_Sf3fEXT5VZJ8hVYSbZoVTXcun1FeDtb2%3D9w%40mail.gmail.com?utm_medium=email&utm_source=footer>.For more options, visit https://groups.google.com/d/optout.
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