I think the answer is yes - but not in quite the way you are thinking. The neon is being interfered with by emmisions on the E/M spectrum - but the visible part of it! I can't quite remember the exact mechanism but neon indictors can degrade to a point at which they will only strike/ remain struck if exposed to external illumination, it'll degrade further with time and be completly failed, but there is a point when they are light sensitive

Not sure how to comment, so I will try a question and see what comments others make:

Have you ever been on the old London Underground trains and seen the black rings moving along the fluorescent light tubes in unison, creating a strobing effect?

Am I showing my age? Is there any fluorescent lighting left on the London Underground?

I have an ancient neon bulb it's about the size and shape of a 15 watt pygmy bulb think it dates from the 40s or 50s.  An odd thing I noticed which backs up phoenix reply is if I power it in a dark room it has a small delay before striking if its daytime or the room lights on it comes on instantly. Other than that it's totally reliable 

I have used the indicator neon tubes (the sort used in sockets and switches that are a bit smaller than a baked bean) as RF detectors of very short pulses- biassed just below ignition (about 70-80V from memory) the additional pulse  energy tips them into conduction, and then an avalanche of ionisation means it stays lit until the supply drops away. By suitable choice of RC time constant one can make  'pulse stretcher', that turns any very short duration  RF signal of any frequency over a very wide range  into a burst of DC, that can be counted - rather like the clicks in a Geiger counter. A radio EMP counter if you like.

In terms of radio reception its more deaf than a crystal set, and totally untuned, but the qualities of 'responds to anything large enough ' and 'not destroyed by overload' are both sometimes useful.

The easy strike ones have radionuncleides in to give them a bit of a head start - but they don't make such good detectors.

By the time they are flickering the ignition voltage has risen by a mix of gas loss and electrode evaporation, and presumably it is very sensitive to the odd volt more or less, far more than a normal appliance.

You may find nothing wrong, other than both the mercury vapour in the florry and the neon in the indicator  are as it were on the way out - both will become very voltage sensitive, just before giving up the ghost altogether - at that point spikes on the mains or a volt or two of RF may well be the difference between strike no strike and affect both.

And yes, they are also light sensitive - for RF detector use they needed to be blacked out.

Mike.

PS the earlier  tubes the underground used to be DC -  and now we really show our age - that was the era of wooden escalators and mostly smoking carriages and the odd non-smoker, or from the mid 1970s, replaced by transistor inverter designs  running at a few KHz, and by then mostly non smoking carriages and the odd smoker.

The DC ones used to leave the tube dark at one end, and the inverter ones use to get a pretty stripes effect that moved a bit as the transistor bias changed and the frequency of the inverter wandered. Given it was all based on a traction voltage of 660 or so, that was soemrthing more like 500 on the train when accelerating and drawing peak current, and more like 800 plus when braking hard and regenerating back into the rails, precise stability was not really a feature.

All led lights with regulation now I think.

Mike.
 

Thanks all - so there are some possibilities - I'll report back when I know more about this particular situation.

Have you ever been on the old London Underground trains and seen the black rings moving along the fluorescent light tubes in unison, creating a strobing effect?

I do recall seeing that on some buses years ago - so definitely not unique to tubes on the tube. All gone LED now though.

  - Andy.

the stripes may be a visible indicator of   the quantisation of atomic energy levels.  The electrons emitted in the very low pressure mercury vapour accelerate along the tube, picking up speed almost ballistically,  increasing their kinetic energy such that  1/2mv² =e.V, where the 'V' is the voltage drop moved along the tube from the initial start, and e is the electron charge.

 The suggestion is that once it has enough energy to ionize an atom of mercury, then it does so, but loses its kinetic energy in the process, and has to start picking up speed again more or less from rest.

This leads to any one electron having a velocity over distance (and time for that matter) that is a sort of sawtooth function of position along the tube, and as the ionization is at maximum where the velocities are highest, bright  ring spacing that are the tube length divided by the no of times the ionization voltage divides into the total tube voltage . (it takes about 10eV to get an outer electron fully off a mercury atom, and the tube voltage is about 10 to 15 times that so a dozen stripes perhaps )

In a normal 50Hz sine wave situation, the stripes all smear out, and the rings are only then visible on fast camera or with DC discharges, and clear rings are only visible in situations where there is not a high current density so not too much collision broadening, and the supply is either DC, or a square wave of the same peak voltage in both directions, or pulsed at a frequency that matches a sub multiple of the transit time to accelerate between the bunches.

Mike.

edit don't confuse v for velocity and V for voltage

PS

The electron starts from rest (near enough) so the kinetic energy gained is given by ½mv² where m is its mass and v is its speed.

So we can say that: ½mv² = eV

The mass of the electron is m = 9 × 10^-31 kg

The electronic charge is e = 1.6 × 10^-19 C

For an electron gun with a voltage between its cathode and anode of V = 100V without collisions, the electron will have a speed of about v = 6 × 10⁶ m/s and 10V is about v = 2 × 10⁶ m/s 
Its all pretty quick.

I suppose there are millions of people aged thirty and younger who have never watched a cathode ray tube television or used a CRT computer monitor and experienced the screen disturbances that were common due to electrical and atmospheric conditions.

en.m.wikipedia.org/.../Cathode-ray_tube

Sparkingchip said:

I suppose there are millions of people aged thirty and younger who have never watched a cathode ray tube television

You would have to drag me kicking and screaming away from my CRT tellies. I much prefer the quality of the picture. Even better are the replays from the 4:3 days, which are shown exactly as they were intended.