What is off camera is a regulated lab power supply set at 180 Volts.
So, a DC supply, no multiplexing.
As you see, one of the other tubes is lit, too!
So somehow the anode voltage is capacitively coupling inside the tubes to a
nearby cathode and trough that, powering another tube.
If
Well, tried cleaning the board to the extremes, inspecting under microscope,
removing the IDC-connector etc. and no change.
I’m feeling that i’m overlooking some simple, so i whipped up a set of wires
connecting two nixies only by wires - only the 10 cathodes are connected, not
the anodes.
Per,
Very interesting result.
Does this experiment produce the same result with fewer wires connecting
the tubes? I so, what number of wires is needed to produce this result?
Is there any AC component to your HV power?
Does this experiment produce similar results with a different type of
..or a very thin piece of copper strand left over from the milling.. have
you done a VERY close inspection of the board? (magnifier or a microscope if
available?)
Dan
-Oprindelig meddelelse-
From: John Rehwinkel
Sent: Sunday, June 07, 2015 8:14 PM
To: neonixie-l@googlegroups.com
Well, i guess it’s my own fault starting to describe the “driving”.board when
having this problem that i put myself into.
What you see on these two pictures is what i am experiencing. No
microcontroller, Arduino or shield is used here. Only my homemade board with 4
tubes.
Per,
Hi. I built many copies of several types of Nixie clocks about 10-12
years ago, using multiplexing. They worked very well, with no ghosting
at all.
Things to look for:
1. Ensure that you have a dead time after the anode is turned off,
with the same cathode selected, for about a
Jonathan,
No problem - it was a pleasure to share it with you!
If I should stumble upon one I will let you know. Sometimes I get hold of
the wierdest stuff.. :)
They seem to be quite rare, but I have seen them for sale here in Denmark -
even on Ham markets. That's where I bought mine. If I
Dan,
I could pay somewhere around what you paid. Non-working would be fine,
although we like working ones! Shipping would be a bear. I'll file it
under hopeful fantasy. :-)
I have seen the Yaesu ft-501. Cool looking radio but I'm holding out for
neon!
Get yer license! Easy and
I think that you should try to lower the value of the 100k resistor across
the base-emitter of every MPSA92 to say some 10k-22k, they will not be
fully turned off in some instances with the 100k resistor.
Did you use the correct anode pin for the IN-4? Have look
here:
Can you show a photo of the ghosting?
Do you have more than one tube connected when the ghosting appears or just
one?
Have you tried biasing resistors on the cathodes?
/martin
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Please disregard the shield that i am using.
It doesn’t exist right now.
On my bench i have a 180V power supply, my board, two wires and a resistor.
I tried with 2.5 / 3mA current per tube.
Connecting the power supply to the anode-pin (Pin4) on the tube trough a
suitable resistor for 2.5mA
This is due to the unused cathodes floating, as they are not supplied with
a voltage that ensures that they are turned off - use biasing resistors and
they will turn off.
Have a look at this
thread: http://www.vintage-radio.net/forum/showthread.php?t=82934 where
there is a nice circuit
Also do some tests where you raise the voltage to 200V with a correct anode
resistor as some of the Russian datasheets mentions a minimum anode voltage
via an anode resistor of 200V to get proper function, 180V is a bit low.
You can also try to connect all three of the anodes together, pins 4,
Did some testing now, I pulled wires off until the problem went away. I only
need two wires connected to reproduce the issue!
See this:
https://www.dropbox.com/s/5vk6bq617v2cz9u/Nixie11.JPG?dl=0
https://www.dropbox.com/s/u84kzterr8jfvhm/Nixie12.JPG?dl=0
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