I currently build a getter flasher according to Ron Soyland‘s design (he will publish it on his site soon). There is a few photos from the building process:
Finally, the shed is finished and I can start moving all the equipment that I gathered in recent two years there. Building of the shed was the major job during last 5 months, I didnt have much time for real nixie tube research, but that changes! I made the glassblowing stuff working today – torches, propane-butan bottle, oxy concentrators, manifold and so.. I also moved some of the stuff here, it is waiting to be sorted out..
New addition to the workshop, Heathway glassblowing lathe. I got it on eBay and it took almost a month to arrange a trasport from UK here to Czech republic. But it finally came off and it is now sitting firmly on the concrete block for my future garden lab (masked as garden shed) 😀 This lathe was manufactured in 1968 in UK and served all its life in a university glassblowing lab. That lab was cancelled around 2012 and the equipment was sold out.
I am currently spending all my time building the shed so that I can accomodate all the stuff here. Once it is finished I will feed You with glowing wires continuously 😉
I plan to use that lathe for doing all the glasswork for nixie tubes..
I decided to switch to oxygen concentrators from liquid oxygen in tanks. The tank is empty really fast and getting a full one is bothering, time and money consuming 😉 So I bought a slightly used Oxymat 3 from eBay, it was sold as-is and I counted with some malfunction. This one is a new model and has only 4760 hours on it, the price was 150 EUR. When I turned the oxycon on, it started to beep and signalised a problem with red LED. So I took it apart and found one plastic fitting broken, it was the fitting what is connected to the can with sieve material. This fitting has a G 1/8 thread, I found one brass fitting with that thread in my stock, so I mounted it into the can sealing it with a teflon tape. The pressure in the can is around 2 bar (30 PSI), not much.. So the seal by teflon tape is OK here. I insert a 6mm OD copper tubing in the place of the original fitting and connected it to the brass fitting with PVC hose.
My leak detector suffered another defect. I was just doing some tests of the filling manifold while the filament was suddenly turned off and the needle of the vacuum gauge went out of the scale. After some time spent by looking for the problem, I found that the transformer is really hot, 110°C, that was really bad. It meant that there would be probably shorted winding.
I finally got a new custom transformer from Bohemia Trafo, good communication, great quality and reasonable price of around $60, the transformer has 9 windings!
I still havent finished the repair yet, but it looks it will be OK..
I almost finished the oven for baking out nixie tubes.. I had to replace the heating element because the previous one melted 😀 The only thing I had to add is the fuse 😉
The oven will work up to 500°C, I plan to bake the tubes at temperature of 480°C. The limiting element is the temperature sensor, it is rated for 600°C. The PID controller (MyPin TA4) works to 1200°C, the fire-resistant board (white material) should work up to 1150°C. I limited the power to 200W, the oven goes to 450°C in 45 minutes.
If You are interested in details, just ask in comments..
As usually, I thanks to Ron for his patience and help with building that stuff!
The last thing I had to make was a connector to neon bottle. This is a low pressure (12 bar) disposable aluminum bottle used in neon sign making. There is 7/16 UNEF thread, it uses the same standard as cans for camping stoves. I machined it from brass so I would be able to solder the copper capillary into it directly without playing with teflon washer. After screwing the connector to the bottle, there is no flow from of the gas. You have to turn down the stem where is a thorn, this thorn opens the seal in the bottle and gas is released out. The gas fills the inside space of the connector and it could be closed again. Now there is a few cm3 filled with neon of pressure at 12 bar, plenty for an experiment 😉
I have been looking for reliable vacuum needle valve for a long time. It should not be to expensive, it should allow me to control the flow fine and not cost much. I tried glass system, cheap valves from China and more, but I was not satisfied with any of these. But as usually, Ron came out with great design of a needle valve what could be made on a lathe easily. Just a aluminum bar, some common fittings, teflon rod and a piece of a mild steel bar. Easy! I decided to take some photos during machining so that anyone could make his own!
The last part of the manifold was the pressure gauge, I had the 0-100 torr baratron, but no controller. The baratron needs supply of +15V and -15V. It gives linear output of 0-10V for 0-100 torr. So I build a simple power supply using two zener diodes (15V) and two 15Ω resistors. If You are interested in schematics, just write a comment. The input power is 40V, output ±15V. A cheap voltmeter from Ebay was used to display the output: