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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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10th Oct 2019, 4:33 pm | #21 |
Octode
Join Date: Mar 2006
Location: Co. Durham, UK.
Posts: 1,111
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Re: Vintage neons
'Cold Cathode Tube Circuit Design' by D. M. Neale.
Chapman and Hall, 1964. |
10th Oct 2019, 5:09 pm | #22 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,562
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Re: Vintage neons
Hi.
The book can be viewed here: https://archive.org/details/ColdCath...eCircuitDesign Regards, Symon |
11th Oct 2019, 9:30 am | #23 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
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Re: Vintage neons
Small wire-ended neons were also commonplace in various 1950s/1960s counter circuits, where they provided threshold-controlled-switching/triggering and 'gating' functions in much the same way as you'd use a Diac - I remember as a student acquiring a bunch of old desk-calculator boards [I suspect from something like an "ANITA"] each of which had a cold-cathode numerical-display tube, a wire-ended thyratron, and lots of flat plastic-encapsulated diodes as well as the neons.
A neon is ideal in such simple logic circuits, where it acts as a kind of Schmitt Trigger/bistable. Thinking of relaxation oscillators, I remember also seeing a circuit for a crystal-calibrator circuit in one of the ham-radio magazines, where a classic neon/resistor/capacitor oscillator running at around 10KHz had a 100KHz signal from the crystal injected into it so the relaxation-oscillator frequency became locked to the xtal and gave you a set of 10KHz calibration-points. Also, some of the T/R tubes used in the waveguides of RADAR sets to shield the receiver crystal-mixer from the high-level transmitted pulse used Neon - when the pulse arrived the Neon ionised and essentially placed a short across the waveguide so no RF could continue down the line to the receiver. Water-vapour was also used as the 'filling' in some T/R tubes! |
11th Oct 2019, 9:39 pm | #24 |
Heptode
Join Date: Jan 2009
Location: West Lothian, UK.
Posts: 760
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Re: Vintage neons
Lots of interesting neon circuits (including sequential and random flashers, and-gates, counters, voltage references etc) in this book:-
https://ia802904.us.archive.org/14/i...eNeonLamps.pdf
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George |
11th Oct 2019, 11:23 pm | #25 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
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Re: Vintage neons
Back in #10, the question about neons in 'scopes. Various uses as already mentioned. One which caught me out for a while was the mains indicator on a little TQ S54. It flickered, but I failed to connect it to the "jumping trace" on the screen. Replace neon, trace as steady as a rock.
I remember our physics lecturer explaining the relaxation oscillator circuit at tech. He said it had been used as a timebase circuit in scopes. I used such circuit for comparing capacitors for one of his practicals. Years later when I first played with valved TQ scopes, there were many stick type EHT rectifiers which tended to go low output. I knocked up a relaxation oscillator using an old 'scope transformer with a good 1,000v secondary as a quick test for the HV rectifiers. If low flash rate, BY182 and series resistor replaced the unit. Les. |
11th Oct 2019, 11:27 pm | #26 |
Banned
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,704
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Re: Vintage neons
I only have a modest collection. Apart from the box of 100 NOS CV2213 that was given to me by a supplier as it was old stock and hadnt sold in years.
He still has many boxes of them. First ones at top are NE-2 for tremelo circuits in guitar amps. Next four are "Signalite Z83R4-A references. A lone NE51. A couple of front panel indicators for 240 volts. Joe |
11th Oct 2019, 11:42 pm | #27 |
Banned
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,704
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Re: Vintage neons
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12th Oct 2019, 9:20 am | #28 |
Nonode
Join Date: Jun 2004
Location: Norwich, Norfolk, UK.
Posts: 2,543
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Re: Vintage neons
Here's a video of my nixie clock https://www.youtube.com/watch?v=F4v7IDIYiNQ It uses neon ring counters to divide up the mains frequency into hours, minutes and seconds.
Back in the 60's you could buy neons with specific striking and maintaining voltages to be used in ring counter circuits. Unfortunately my clock doesn't and it didn't prove reliable for very long so I can't recommend it as a worthwhile project. It was fun making it though! There's lots of info on this website https://www.dos4ever.com/ring/ring.html Regards David
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http://www.youtube.com/ My Nixie Clocks |
12th Oct 2019, 11:22 am | #29 |
Nonode
Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
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Re: Vintage neons
I helped a chum pull an old shed down and these were inside
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22nd Oct 2019, 2:46 pm | #30 |
Pentode
Join Date: Sep 2019
Location: Perth, Western Australia, Australia.
Posts: 199
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Re: Vintage neons
Back in the day, I worked in a "Broadcast Installation Depot".
We made up racks which were prewired from a Mains power distribution panels at the base of each rack. We also made the power distribution panels themselves from scratch, cutting & bending the metal, painting it with "Hammertex" or "Brolite" paint to give it a "hammered" appearance. Above a row of DPST toggle switches, there was a corresponding row of neon indicators (the ones encased in a plastic rectangle). It was discovered that we had fitted 125v neons instead of 240v ones, so we had to remove them, replace them with the correct voltage devices, & render the removed ones unuseable, in case they accidentally found their way back into the supply chain. Initially, we temdered them "unuseable" with a hammer, then someone suggested an easier way would be to sling them at the concrete floor. On doing this, we were astounded by the neons briefly "flashing" on impact. This definitely "killed" them, but we could not work out a mechanism whereby a neon would flash due to physical force. Anyone else experienced this phenomenon? |
22nd Oct 2019, 4:40 pm | #31 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,676
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Re: Vintage neons
I haven't experienced that, have you ever ripped open the gummed flap of a Jiffy bag in total darkness?
I can't explain that light-show either.
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22nd Oct 2019, 5:00 pm | #32 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
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Re: Vintage neons
There's a range of materials that exhibit "Triboluminescence" and "Piezoluminescence". I wonder if your neons maybe had some sort of phosphor on the insides of the envelope??
https://en.wikipedia.org/wiki/Piezoluminescence https://en.wikipedia.org/wiki/Triboluminescence |
22nd Oct 2019, 5:33 pm | #33 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
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Re: Vintage neons
I'm sure I recall something about the peeling of "Sellotape"-type adhesive film having been found to produce surprisingly high energy EM radiation, even X-rays, and that some had postulated that this sort of effect could be the basis of another pathway to cold fusion. (No, I don't think it was an April Fool, neither had I been dreaming or hitting the Evo-Stik!)
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23rd Oct 2019, 6:27 pm | #34 |
Rest in Peace
Join Date: Sep 2010
Location: Ripley, Derbyshire, UK.
Posts: 785
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Re: Vintage neons
If you are a neon enthusiast, and want to see a really remarkable display of functioning neons, try to get to see inside an early Philicorder electronic organ when powered up!
I have fond memories of those instruments, and although there was quite a large number of neons in the generator circuits, they proved quite reliable. I suspect that they were "burned in" at the factory before being assembled into the organs. Sadly, no pictures available, but a part of the circuit (tone generator) where the neons were used. There were many more than shown in this part-circuit diagram! Tony. |