We make a very dim display much brighter by stripping the cathodes. (This is a reload of the previous video because the last section didn't render properly).
Actually, the Lee filters are also commonly used for theatrical stage lighting. Rosco, GAM (Rosco bought GAM a few years ago) and Apollo filters are also used a lot in the theater. (Where they're referred to as "gels" because the early color filters were made from geletin.) There is some concern that these mylar color filters might eventually go away as color changing LED fixtures become the standard.
Yep, they are lighting filters. I cant see how you would get the same quality f light from a LEDs fixture. Modern LEDs have high CRI performance but the spectral spread from a red LED is much narrower than from a red filter with a tungsten or high-pressure metal halide white light source. I suppose it depends on the compensation in the signal processing.
Hi, can you describe what you have done? Setting an AC-voltage of aprox 4.5V on the wires does 'regenerate' the display? Or did you do other modifications. I have the same problem here.
It depends how far gone your cathode is. You have to check all the other capacitors in the circuit that supplies the bias voltages. See the other videos they cover the mains issue. That is likely your problem.
1:40 If I remember correctly, low heat on the filaments in fluorescent bulbs used to accelerate the sputtering of the electrodes. Could it be the case with these VFD displays?
I think you are likely correct. Thorium coating .can be stripped away if it is run cold. What emissions there are are focused on closer areas of the cathode with the strongest electric field. Akin to spark erosion. The display was much brighter after a tickle. On CRTs we used to apply 400V to the control grid and pas a high current from the cathode with the heater on. On Mullard tubes this worked a treat but on Raytheon ones and Trinitron it didn't work hardly at all. We got the feeling that the thorium coating had been contaminated with ions floating about in the tube and that we were blasting off the outer layers to expose a fresh surface. .
Hello friend, maybe you can help me. I have a VFD, taken from a VCR, and the same (VFD) was working. Some time later, I went to do tests to find out the VFD pinout and it didn't light up. I looked more closely at the VFD and realized that the glass bubble, which is used to remove air from inside the VFD, had a broken tip, thus allowing air to enter the glass. So, do you know of any way to get around this situation? I mean, some way to remove the air from inside the glass and seal it (with glue) again. Thanks.
Sorry I dont. I assume it is a a high vacuum inside the envelope and you need a diffusion pump and a method of firing the getter to resotore it. I am afraid it is scrap...
I have a yamaha rx-v479 amp that has a dot matrix vfd blue display. That is not as bright as it should be but also patchy. Quite a lot of segments are dimmer. Would this fix it. Although I don't have that kit to 'heat it up' could you do that? I'm near Evesham, UK
Hi Adrian, before you regenerate first make sure that the voltages to the VFD are in order. The usual problem is that the bias generator capacitors have gone low in value. Cheers.
I have a small issue with a Sony MDS-JB920 Minidisc VFD having dimming on the right half if i send you by email the diagram could you help me out please. I can do the repair but just need a bit of pinpointing help. Many thanks. Darryl
