Re: [neonixie-l] Re: IN-13 currents or Dislyxia Rides Again!!!

[Joe Croft]

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!

-joe

On Thu, May 19, 2016 at 5:32 PM, Joe Croft <cro...@gmail.com> 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 <greg...@hotmail.com> 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 the Google Groups "neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+...@googlegroups.com.
To post to this group, send email to neoni...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/b6cbe906-453b-4e5b-8062-2c80848ba8df%40googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

[Instrument Resources of America]

Joe, Don't fret too much over this. We've all been there at one time or another in our lives. Good luck, you'll get er done.  Ira.

To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAE%2BVk6OhRLRy27_Sf3fEXT5VZJ8hVYSbZoVTXcun1FeDtb2%3D9w%40mail.gmail.com.

[Jonathan Peakall]

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!
>
> -joe
>

Argh! Been there, done that and then lost the tee shirt!

Sorry brother. I know I was pretty $%#!!. Just know that you are not alone.

Jonathan