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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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9th Oct 2019, 6:33 pm | #1 |
Heptode
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 632
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Vintage neons
Found these today, and it got me thinking about the first experience I had with neons. Bought an opal neon panel indicator from radiospares, as a child (started early), and was annoyed when the lens was just white and didnt look like an opal.
Found these today when looking for something else, was given them as samples in the 1990’s. Im guessing the blue and green ones are actually argon with a phosphor, dont know whether theyre still a thing. Also fired up an old Phillips BC magnifier ended neon, I seem to recall these being used in domestic appliances. Anyone else got any interesting neons ? |
9th Oct 2019, 6:51 pm | #2 |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,082
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Re: Vintage neons
I've got a couple of the magnifier-ended neons, also a few MES-based neons (with the neon bit full-diameter).
I've never played with a phosphor type, alternative colour tube, though. Favourite neons have to be Nixie tubes! |
9th Oct 2019, 6:59 pm | #3 |
Heptode
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 632
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Re: Vintage neons
Ooh yeah forgot about those. Made a nixie clock with a German kit and some end display ones out of HP counters but sold it on and no pictures
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9th Oct 2019, 7:13 pm | #4 |
Hexode
Join Date: Mar 2008
Location: Bristol, UK.
Posts: 388
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Re: Vintage neons
Did the large bayonet ones illuminate Otis elevator buttons? I have some somewhere plus a few oddities,I'll try to find them.Les
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9th Oct 2019, 7:20 pm | #5 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,998
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Re: Vintage neons
The ones with the end-on magnifier - they were used until quite recently to illuminate industrial control-panel pushbuttons [the ones I remember were made by Klockner Moeller].
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9th Oct 2019, 11:19 pm | #6 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
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Re: Vintage neons
Here is a "beehive" neon I acquired a couple of years ago in memory of one I had as a nightlight when I was a child. I was most upset when that childhood neon died - the glass cracked and let the air in.
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9th Oct 2019, 11:45 pm | #7 |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
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Re: Vintage neons
The blue and green neons are still available, mainly from Eastern European ebay sellers, usually wire ended but sometimes with e10 or ba9s caps.
With LEDs taking over the world, I suspect that production of blue and green neons has ceased and that those for sale are NOS. Much rarer are white neon lamps, true white phosphor lamps that emit a white light, not standard orange ones with a white covering, and that therefore still give an orange light. The large beehive neon lamps are now in short supply, and sell for silly money on ebay. They were popular in the last war as the minimal light output was unlikely to attract the enemy provided that the lamps could not be seen from the air. |
9th Oct 2019, 11:52 pm | #8 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,553
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Re: Vintage neons
I have got a rectangular one.
If it is powered with DC from a Megger it works like a polarity indicator. I have got a handful of old neons but none are beehives. |
10th Oct 2019, 3:54 am | #9 |
Nonode
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,339
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Re: Vintage neons
Red, green, orange and blue neon's are still available from RS, as are the magnified ones, so they are still being made.
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10th Oct 2019, 8:43 am | #10 |
Hexode
Join Date: Jul 2010
Location: Royal Berkshire, UK.
Posts: 471
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Re: Vintage neons
This is a question I should probably know the answer to, but don't.
Why were neon's used in some oscilloscopes? I've seen them mounted on the front panel to show which direction the trace was hiding, but the one's inside the instrument, what role were they performing? My first encounter with neon's was with a Rima(?) free-standing oil filled radiator (which we still have and works great). The original neon was scorched/silver inside, producing very little light. A replacement neon rescued from a scrap extension-block was put to good use. Mark
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10th Oct 2019, 9:18 am | #11 | |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
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Re: Vintage neons
Quote:
They could have been used to stabilise the screen-grid voltage of pentodes. They could also have been used as part of DC coupling between a valve anode and the following grid - losing 80V (or 160V if two in series) while still passing on a small change from anode to grid. Both these are important if the oscilloscope's response is to go right down to DC, when capacitors are not an option. Last edited by kalee20; 10th Oct 2019 at 9:19 am. Reason: Fix quote |
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10th Oct 2019, 9:53 am | #12 |
Octode
Join Date: Dec 2017
Location: Morden, Surrey, UK.
Posts: 1,558
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Re: Vintage neons
They were frequently used in the EHT circuit as protection devices for the semiconductor circuitry.
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10th Oct 2019, 9:54 am | #13 | |
Nonode
Join Date: Oct 2008
Location: Warsaw, Poland and Cambridge, UK
Posts: 2,677
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Re: Vintage neons
Quote:
Chris
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10th Oct 2019, 10:01 am | #14 |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
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Re: Vintage neons
Other uses include,
To shunt relay coils and thereby limit the back EMF to about 80 volts on de-energisation. This works with a supply of either polarity unlike a silicon diode, and also allows the relay to open more quickly. In vehicle mounted radio sets, connected between the aerial and the chassis to shunt to earth any otherwise damaging voltages that might result from capacitive coupling when the vehicle passes under high voltage grid lines. In small or cheap strobe lamps instead of the much more costly xenon flashtube. Allows rotating machinery to be examined as if static. In conjunction with a deep red filter, as a "safe" light for handling photographic materials in a dark room. More reliable and longer lasting than a small filament lamp, less heat produced. |
10th Oct 2019, 11:46 am | #15 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,208
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Re: Vintage neons
Another use (together with a resistor and capacitor) is to make a simple relaxation oscillator. It depends on the fact that a neon bulb takes a higher voltage to strike than it needs to keep conducting. The capacitor charges through the resistor until the neon strikes, the capacitor then discharges through the neon until it drops below the maintaining voltage of the neon, the neon goes out and the cycle repeats.
My Agaphone wire recorder has a neon on the panel. It is used both as a recording level indicator (glows when the signal is just too strong I think) and as a relaxation oscillator for the signal tone. Some old HP counters (5243, 5245 at least) latch a BCD digit and its inverse on 8 neons inside, using the difference in striking and maintaining voltages as the latch function. This neons then illuminate CdS photoresistors on a ceramic plate which form a decoder tree to drive the nixie tube. |
10th Oct 2019, 1:17 pm | #16 | |
Nonode
Join Date: Feb 2005
Location: Worcestershire, UK.
Posts: 2,533
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Re: Vintage neons
Quote:
No, it wasn't best practice to connect neons in series like this! Its virtue to me was that it was simple. It also ensured the sawtooth sat on a DC bias around the same value as the 400v 'EHT', which suited the electrostatic tube. It did work. Steve |
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10th Oct 2019, 2:16 pm | #17 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: Vintage neons
Way back in the late 70's we had a ( think it was a cable pressure tester) that checked the result from several cable pressure circuits in our TRS . Initially it was fed from the exchange pulse ,but when this facility was made redundant, I was one of the blokes who designed a circuit based on a neon ( cold cathode) to fire on a T/C circuit. Simple circuit using a 200 type relay, where one contact discharged the T/C capacitor and another stepped the stepper motor on a step.
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10th Oct 2019, 2:43 pm | #18 |
Heptode
Join Date: Jan 2008
Location: Shrewsbury, Shropshire, UK.
Posts: 841
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Re: Vintage neons
Then there's neon regulators of course. There were a lot of these used in radio equipment as stabilizers. VFO's were often fed from OA2, 90C1's and VR150 etc neon stabilizers. They all imparted a lovely glow. Such nostalgia, we don't really get that with ball-gate array chips!
I have quite a collection of odd neons, both those intended for illumination, indication & regulation. maybe I should put them on display. (illuminated of course), when I get time. David. |
10th Oct 2019, 3:54 pm | #19 |
Hexode
Join Date: Jul 2010
Location: Royal Berkshire, UK.
Posts: 471
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Re: Vintage neons
Thank you chaps, a good few uses and ideas for neons.
Time for me to think-up a useful project. Mark
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10th Oct 2019, 3:57 pm | #20 |
Dekatron
Join Date: Jun 2015
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Re: Vintage neons
There is an interesting book 'Cold Cathode Tube Circuit Design' which I am told is very expensive second-hand but you might be lucky. It covers more complex cold-cathode devices like dekatrons, but some of it is on 2-electrode neons. Things like making shift registers with them, etc.
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