I noticed in all 3 tubes there is a slight haze/cloudiness or peppering (not the definitive black dots) on them. I just got an L3 unfilmed and had the same and was wondering if this is common or to be expected. Gain-64k SNR-33.5 CR-72 EBI-0.8 PS-2047
Pepper is very common in various imaging tubes, and it is considered an acceptable flaw in the manufacturing process. However, in the case of aviation imaging tubes with the suffix "ua," there are strict limitations on the size and position of pepper particles.
@@shan-chunhsu7666 Thanks a lot for responding. I guess I was expecting a HD tube that looks as clear as a camera for ~$4k since the green phos. I had before was a bit clearer. I was requesting a RMA from the manufacturer.
@@Steven_M. "Cloudiness" can be caused by a high EBI. A tube with very high EBI will have a veiling glow across the screen that lowers contrast. This will be worse when the temps are high and almost go away when the temps are very low. I am not saying this is the case with your tube, I am only saying that I have had a couple of high EBI tubes that had a milkiness to the view. This video shows the effect that EBI has by comparing two tubes, one with lower EBI (the first tube) and the second with the higher EBI. The first thing you see is the glow in the tube when there is zero illumination (Objective capped). Note how much brighter the second tube is when there is zero light. This is the signature of high EBI. If you go into a dark room and cap the objective, if you can see that there is a strong glow in the eyepiece with no signal, that is high EBI. Even the lowest EBI tube will have some EBI, and usually it has to be pretty meaningful before it will cause an issue, but I would not dismiss it. th-cam.com/video/kzVMwzoZwOQ/w-d-xo.html This is another video. Threshold level means that you are in the darkest condition where a tube will produce an image. A .1 EBI tube (all else being equal) will produce a usable view in much darker conditions than a 1.5 EBI tube will As the video shows, you can easily see the difference between .1 and .6, or between .5 and 1.5. Important to remember that EBI goes down as temps drop. th-cam.com/video/5qRl0Dkf8dM/w-d-xo.html *I am not sayin that this is what you are seeing* . I am only saying that it is a possibility. The military used to allow an EBI of 2.5 or less, but with OMNI 8, the allowed it to be as high as 2.5, and now they have back tracked and under the latest contract, the max EBI is now 2, which is the lowest they have ever specified. Most tubes are better than this, running between .8 and 1.6 (based on the specs I have seen). One thing to note is that in general, the higher the photocathode sensitivity, the more EBI there could be. This is just a general rule, and there are always exceptions. The tubes you see in the second video I linked don't have particularly hot photocathodes, but they do have rather unusually low EBI. The third tube still has a pretty low EBI (.6), but it has a much higher photocathode sensitivity.
I don't have Photonis, so I can't make a comparison. The color of the phosphor is a matter of personal preference. Personally, I prefer green a bit more, but the image looks clearer with unfilmed tubes.
I noticed in all 3 tubes there is a slight haze/cloudiness or peppering (not the definitive black dots) on them. I just got an L3 unfilmed and had the same and was wondering if this is common or to be expected.
Gain-64k
SNR-33.5
CR-72
EBI-0.8
PS-2047
Pepper is very common in various imaging tubes, and it is considered an acceptable flaw in the manufacturing process. However, in the case of aviation imaging tubes with the suffix "ua," there are strict limitations on the size and position of pepper particles.
@@shan-chunhsu7666 Thanks a lot for responding. I guess I was expecting a HD tube that looks as clear as a camera for ~$4k since the green phos. I had before was a bit clearer. I was requesting a RMA from the manufacturer.
@@Steven_M. "Cloudiness" can be caused by a high EBI. A tube with very high EBI will have a veiling glow across the screen that lowers contrast. This will be worse when the temps are high and almost go away when the temps are very low. I am not saying this is the case with your tube, I am only saying that I have had a couple of high EBI tubes that had a milkiness to the view. This video shows the effect that EBI has by comparing two tubes, one with lower EBI (the first tube) and the second with the higher EBI. The first thing you see is the glow in the tube when there is zero illumination (Objective capped). Note how much brighter the second tube is when there is zero light. This is the signature of high EBI. If you go into a dark room and cap the objective, if you can see that there is a strong glow in the eyepiece with no signal, that is high EBI. Even the lowest EBI tube will have some EBI, and usually it has to be pretty meaningful before it will cause an issue, but I would not dismiss it. th-cam.com/video/kzVMwzoZwOQ/w-d-xo.html
This is another video. Threshold level means that you are in the darkest condition where a tube will produce an image. A .1 EBI tube (all else being equal) will produce a usable view in much darker conditions than a 1.5 EBI tube will As the video shows, you can easily see the difference between .1 and .6, or between .5 and 1.5. Important to remember that EBI goes down as temps drop. th-cam.com/video/5qRl0Dkf8dM/w-d-xo.html
*I am not sayin that this is what you are seeing* . I am only saying that it is a possibility. The military used to allow an EBI of 2.5 or less, but with OMNI 8, the allowed it to be as high as 2.5, and now they have back tracked and under the latest contract, the max EBI is now 2, which is the lowest they have ever specified. Most tubes are better than this, running between .8 and 1.6 (based on the specs I have seen). One thing to note is that in general, the higher the photocathode sensitivity, the more EBI there could be. This is just a general rule, and there are always exceptions. The tubes you see in the second video I linked don't have particularly hot photocathodes, but they do have rather unusually low EBI. The third tube still has a pretty low EBI (.6), but it has a much higher photocathode sensitivity.
@@aesthetic87804g+ better than filmless?? That’s a joke. It’s no contest at all, filmless wins by a mile
@@aesthetic8780😂
Which would you put in a katana housing, L3 24UA standard gain tubes, or L3 20UAH supergain tubes?
I would go standard gain if you don’t have manual gain on the housing, otherwise they’ll usually be at max gain.
all 3 seem nice
which is better? Omni7 or Photonis high gain green phos?
I don't have Photonis, so I can't make a comparison. The color of the phosphor is a matter of personal preference. Personally, I prefer green a bit more, but the image looks clearer with unfilmed tubes.
Omni 7 is probably cheaper for you. I bet the high gain has better specs too. just up to you. neither are a bad choice
Beautiful
What is the PS??
Photocathode Sensitivity