Date   

Re: My eye sensitivity to blue-violet higher than normal

Harvey White
 

the shorter the wavelength of the light, the better focus you can get.  One reason why IR images are fuzzy (the other may be a compromise between different focus settings).  Since different colors focus at different distances in a lens, you need to have a camera lens designed for this.  Not at all sure that the human eye takes that into account at all.

Spot size is one reason that the DVD (blue-ray) blue light holds more data than a CD (IR light).

Xrays are used in lithography for most complicated ICs, not visible light, IIRC.

Harvey

On 5/23/2021 11:15 PM, Mark Vincent wrote:
It seems I really started something with my post. Thanks to those that have already replied. Any more would be welcome. I have known of my ability to see the higher frequency colours since I was a kid. I do not have any vision problems. All I know is the better ability to see blue to violet better than anyone I have met. Doctors I have told this to do not know exactly why I see better with these colours. It has to be a DNA feature that is determined in the womb. Other light colours do not bother me. Saying I may be a mutant by Mr. Carsten could be right on. A mutation in the DNA is possible if not likely.

Flicker does annoy me. NOVA had a show years ago titled "Can buildings make you sick". I bought a VHS tape of this after it aired to show people I am not the only one. One segment in that show verified that headaches and eye strain will occur to everyone in varying degrees. They used the typical 60 c/s fluorescent light source and a tungsten light on volunteers. The ones said it was easier to read and see under the latter for any length of time. Electronic ballasts operate so fast, the phosphour in the tube cannot fully decay in its glow like a standard transformer ballast. Now cheap LED lighting uses a half-wave supply. Better is filtered dc. Slowing a trace using any P number will annoy anyone. The slower sweep is needed at times, e.g. 20ms/div. I understand the mesh makes traces thicker no matter what P is on the inside.

For colour rendition, white is best. Read a resistor colour band under some light colours and the bands will look different.

It was found that sound on film had better fidelity when a blue to UV light was used on the soundtrack. The higher frequency of the light the higher audio frequencies be put in without the attenuation. Notice a shadow is sharper as the light source frequency increases. IC lithography uses UV.

I only use the scale illumination when needed. I keep it at minimum otherwise. The graticule is seen easily unless the ambient light level is too low. An EMI shield with a blue trace is no problem for me. Trace/readout intensity is kept as low as possible to see. The 7104 is barely visible until the trace is needed to be seen then brought up enough to see while keeping the yellow LED off then intensity back down. This is when I use that model. The crt in this is good, not weak by any means. Protect the MCP.

Mr. Gentry makes me wish convergence was still done. I miss NTSC and delta guns. Here is something for TV history people, Electronicam.

I have noticed the 2000 series never had Opt. 78.

Blue eyed people have less melanin. The mention of the WW2 navy using UV is interesting.

Thanks again for the replies. Anyone else is welcome. I have already learned things.

Mark





Re: My eye sensitivity to blue-violet higher than normal

Mark Vincent
 

It seems I really started something with my post. Thanks to those that have already replied. Any more would be welcome. I have known of my ability to see the higher frequency colours since I was a kid. I do not have any vision problems. All I know is the better ability to see blue to violet better than anyone I have met. Doctors I have told this to do not know exactly why I see better with these colours. It has to be a DNA feature that is determined in the womb. Other light colours do not bother me. Saying I may be a mutant by Mr. Carsten could be right on. A mutation in the DNA is possible if not likely.

Flicker does annoy me. NOVA had a show years ago titled "Can buildings make you sick". I bought a VHS tape of this after it aired to show people I am not the only one. One segment in that show verified that headaches and eye strain will occur to everyone in varying degrees. They used the typical 60 c/s fluorescent light source and a tungsten light on volunteers. The ones said it was easier to read and see under the latter for any length of time. Electronic ballasts operate so fast, the phosphour in the tube cannot fully decay in its glow like a standard transformer ballast. Now cheap LED lighting uses a half-wave supply. Better is filtered dc. Slowing a trace using any P number will annoy anyone. The slower sweep is needed at times, e.g. 20ms/div. I understand the mesh makes traces thicker no matter what P is on the inside.

For colour rendition, white is best. Read a resistor colour band under some light colours and the bands will look different.

It was found that sound on film had better fidelity when a blue to UV light was used on the soundtrack. The higher frequency of the light the higher audio frequencies be put in without the attenuation. Notice a shadow is sharper as the light source frequency increases. IC lithography uses UV.

I only use the scale illumination when needed. I keep it at minimum otherwise. The graticule is seen easily unless the ambient light level is too low. An EMI shield with a blue trace is no problem for me. Trace/readout intensity is kept as low as possible to see. The 7104 is barely visible until the trace is needed to be seen then brought up enough to see while keeping the yellow LED off then intensity back down. This is when I use that model. The crt in this is good, not weak by any means. Protect the MCP.

Mr. Gentry makes me wish convergence was still done. I miss NTSC and delta guns. Here is something for TV history people, Electronicam.

I have noticed the 2000 series never had Opt. 78.

Blue eyed people have less melanin. The mention of the WW2 navy using UV is interesting.

Thanks again for the replies. Anyone else is welcome. I have already learned things.

Mark


Re: Has anyone replaced the Graticule lights with LEDs?

Eric
 

Led moding a 7000 Series Scope after crawling in to my head from a year ago.

The LEDs used were Adafruit / 754 Super bright White Leds. Important notes on these Vforward for the diode being white is 2.5Vdc this is important later. Led Size is 5mm Clear

Dropping resister – None

Power supply open circuit voltage – 8.1 Vdc at full illumination

LED wiring parallel like the old light bulbs

The lamp illumination is current limited by the scope its self. When the LEDs are connected and the illumination on FULL the voltage across the connector in the scope is only 3.2 Vdc this means that the Leds are only drawing about 40mA each this was verified on a 577. This is why the leds don’t burn up with no current limiting resister. This is running the leds at about 2X design spec but after running one like this off a lab power supply for a few hours it is barely warm to the touch and has not moved from a round 0.031 mA current draw Amp meter in the power supply so not the best thing in the word for measurement.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Harvey White
Sent: Sunday, May 23, 2021 6:31 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Has anyone replaced the Graticule lights with LEDs?

LEDs can be gotten in different dispersions, some, for instance, I think at 130 degrees. If you have a 3D printer, you might be able to make a light shroud depending on your needs. If you can do PC boards, then I could recommend a 3 color LED. How to profitably control it is another matter. Otherwise, pick a color depending on what you want.

It might get close to an incandescent lamp.

Harvey


On 5/23/2021 5:15 PM, DaveH52 wrote:
In a few days, I'll be disassembling my 2465 again to install a replacement module for U800. Since it will be totally disassembled, I'm seriously considering replacing the graticule lamps with red LEDs. I plan on 'frosting' the tops so the light will be more diffused. It worked well for the meter on my Kenwood TS-440, except I used white LEDs for that.






Re: My eye sensitivity to blue-violet higher than normal

stevenhorii
 

This may seem crazy, but blue irises are not actually pigmented blue. They
are non-pigmented. The blue color is due to the Tyndall effect (light
scattering). See this:

https://www.aao.org/eye-health/tips-prevention/your-blue-eyes-arent-really-blue

Those with brown eyes have melanin pigment in their irises, so they are
actually brown in color.

There is some evidence that those with blue eyes are more light sensitive
overall, and light may not only scatter, but may pass through even the part
of the iris that is “closed” (i.e., not the pupil) because there is no
pigment to absorb as much light. I know two people, both men with blue
eyes, who claimed to have increased sensitivity to blue light and were
bothered by the blue lights that are sometimes used to indicate the
location of emergency call boxes. I was with them on more than one occasion
when they would shield their eyes from blue light sources (those call box
lights, blue neon signs, blue flashing emergency lights, etc). I never did
understand why they had this, but this article (oriented to
ophthalmologists and other physicians) discusses some of this as well as
the relationship with migraines and the possible causes:

https://www.aao.org/eyenet/article/md-roundtable-solving-photophobia-puzzle

Maybe that lack of iris pigment?

I hope the information is useful.

Steve Horii (I am a physician, but not an ophthalmologist)

On Sun, May 23, 2021 at 19:35 Mark Vincent <orangeglowaudio@gmail.com>
wrote:

I would like to know from anyone in this group that has a good educated to
known medical reason why I have a higher sensitivity and ease of viewing
light that is blue to violet so easily. I understand the rods and cones in
the eye and have enough medical knowledge to understand the Latin and Greek
terms of medical words. I have NO problem in seeing, focusing or any form
of eye strain on light that is in the high frequency part of the spectrum
of blue to violet, including indigo. I have always been this way. One note,
I do have blue eyes if that makes any difference. They are not the striking
steel blue that can look like blue lasers. Jean Harlow had steel blue eyes,
as an example of someone. Blue/ steel blue eyes in a male is far more
common in a male than a female.

Another thing I have with my eyes is that under 50/60 c/s flicker, I will
get a severe migraine and have the vision of "Mr. Magoo" within a few
minutes that takes a few hours to wear off after being removed from the
flickering light(s). For reading and general lighting, I prefer carbon
filament (Ferrowatt). Tungsten is fine.

Brenda mentioned having a RM565 scope with a blue trace (must be P11 by the
model) that she gets eye strain easily. This is what finally made me ask
the group this. Others have mentioned how P11, blue, is nice briefly, not
for any time without the owner having eye strain and hard to focus on. I
have seen older posts on this group and other places online about people
saying blue trace is nice but annoyed by the hard to focus on and eye
strain within a few minutes. I have a couple of friends with blue eyes that
I asked about blue-violet phosphour. They said it is nice to glance at or
for a short time, not for any longer. They said they would prefer P1, P31,
etc, that is in the green area to look at for any length of time, a minute
or more. I will deal with P1 or P31. I find P2 the WORST to look at. The
blue part is fine, the cyan afterglow I find bilious. P7 is not as bad as
the afterglow is yellow with only the blue seen with a proper filter. Even
so, I will keep the intensity of a P7 low so as to only see the blue.

I know storage types need a P31 because of the secondary emission.
Something like the 2467/B or 7104 with the MCP could have been made with
other phosphours when made. The MCP does not care about the phosphour, only
acting like a photomultiplier.

I would like to find the P11 crts for my 556, 7603 and 465. The P31s in
them are in very good condition. I prefer the P11 because of the thinner
trace, ease on my eyes. and faster decay time. To find a 502A with P11 and
T317P11 for my 317 would be great. I know the 502A is 2mc capacity. The
7000 series I have, except for the 7934 and 7104, now have the P11 in them.
I do have good P31 types I removed from the scopes sitting around. I do
have a few of the 300, 400 and 500 series with the P11. If I can find
someone who can successfully rewind the high voltage transformers for the
older types, I would really like P11 for me 545B and 547 after getting
these transformers rewound. The only thing I have seen P16 in is a B&K 1076
analyst. That colour does not bother me at all. So far I have not seen a P5
although having any of these, 3AP5 for example, in place of a P1 would be
great. I know the decay time and light output of P5 is less and P11.

For any plant that has flowers, I do not mind any colour.

Mark






Re: Happy birthday Bob Moog

Tom Lee
 

Hi Carsten,

It looks like a 465. The two models differ subtly in the colored highlighting of the highest-speed sweep ranges. You can barely make out the shape here, but enough, I think,  to match it to the 465.

-- MfG,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 5/23/2021 18:34, Carsten Bormann wrote:
On 2021-05-24, at 02:54, toby@telegraphics.com.au wrote:
https://twitter.com/moogmusicinc/status/1396441500226101249
So what exactly is the Tek scope in the image? 475?

I recognize the HP 400GL(?) at the top of the shelf.

(Maybe there is a higher resolution version of that picture somewhere…)

Grüße, Carsten





Re: Happy birthday Bob Moog

Carsten Bormann
 

On 2021-05-24, at 02:54, toby@telegraphics.com.au wrote:

https://twitter.com/moogmusicinc/status/1396441500226101249
So what exactly is the Tek scope in the image? 475?

I recognize the HP 400GL(?) at the top of the shelf.

(Maybe there is a higher resolution version of that picture somewhere…)

Grüße, Carsten


Re: Happy birthday Bob Moog

Jeff Davis
 

Thanks, Toby

On May 23, 2021, at 6:12 PM, toby@telegraphics.com.au wrote:

On 2021-05-23 9:00 p.m., Jeff Davis wrote:
I feel certain this is legitimate and sent with the best of intentions. However, for every one like that, I get at least 50 that are nothing more than phishing campaigns trying to get me to click on a malware link.

I’m wondering if there might be a safer way to make this available to the group?
Sure. It's just a safe link to a tweet. If you don't like the automatic
linking, you can recreate the URL from this:

twitter dot com/moogmusicinc/status/1396441500226101249

Anyone not comfortable viewing a tweet, ignore.

--Toby

Regards,
Jeff/N0DY
On May 23, 2021, at 5:54 PM, toby@telegraphics.com.au wrote:
Hi list,

Click for a nice surprise.

https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftwitter.com%2Fmoogmusicinc%2Fstatus%2F1396441500226101249&;data=04%7C01%7C%7Cba5219f4da8b4fcda10508d91e50f18c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637574155262188335%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=XYhgc73OFLhWNqYaCu8KhtFCbSW24oYo8CUY4jxOCYk%3D&amp;reserved=0

--Toby












Re: My eye sensitivity to blue-violet higher than normal

Carsten Bormann
 

On 2021-05-24, at 01:34, Mark Vincent wrote:

I would like to know from anyone in this group that has a good educated to
known medical reason why I have a higher sensitivity and ease of viewing
light that is blue to violet so easily. I understand the rods and cones in
the eye and have enough medical knowledge to understand the Latin and Greek
terms of medical words. I have NO problem in seeing, focusing or any form
of eye strain on light that is in the high frequency part of the spectrum
of blue to violet, including indigo.
Well, you’re a mutant then.
(I’m not joking; you might very well be [2].)
Any other anomalies in your color vision?

Let me explain what is really special about the blue-sensitive cones:
Only about 2 % of our cones are of that kind [1]. That is enough for our eyes to be quite *sensitive* to blue light, but it gives a much lower *resolution* for blue light than for the green-to-red part of the spectrum.

That is why it is harder to resolve fine details in blue-on-black or yellow-on-white or any other contrast that differs only in the blue part of the spectrum. As long as the features are big, no problem. But at some point the small number of blue-sensitive cones just doesn’t have the resolution we are used to having for green-to-red.

I have no comment on your other observations, but when it comes to average human vision in the blue spectrum, it is important to distinguish sensitivity (which is great) from resolution (which is poor).

Grüße, Carsten

[1]: https://en.wikipedia.org/wiki/Cone_cell#Types
[2]: https://en.wikipedia.org/wiki/Tetrachromacy#Humans


Re: Happy birthday Bob Moog

toby@...
 

On 2021-05-23 9:00 p.m., Jeff Davis wrote:
I feel certain this is legitimate and sent with the best of intentions. However, for every one like that, I get at least 50 that are nothing more than phishing campaigns trying to get me to click on a malware link.

I’m wondering if there might be a safer way to make this available to the group?
Sure. It's just a safe link to a tweet. If you don't like the automatic
linking, you can recreate the URL from this:

twitter dot com/moogmusicinc/status/1396441500226101249

Anyone not comfortable viewing a tweet, ignore.

--Toby

Regards,
Jeff/N0DY
On May 23, 2021, at 5:54 PM, toby@telegraphics.com.au wrote:

Hi list,

Click for a nice surprise.

https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftwitter.com%2Fmoogmusicinc%2Fstatus%2F1396441500226101249&;data=04%7C01%7C%7C1158d649c4d74a50840308d91e4e853c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637574144847409180%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=k5pDK8VTiiYgwYBCTbz5JZFvHfXadv3Rkb0Xuo7waow%3D&amp;reserved=0

--Toby








Re: Happy birthday Bob Moog

greenboxmaven
 

His accomplishments were incredible. Perry & Kingsley, Dick Hyman, and Wendy Carlos made exceptional music on his instruments. For another type of synthesis, this time visual, also in Asheville, make an internet search for "Scanimate".  A lifelong friend has perhaps the last two of them in existence in his studio there. I am not sure if he ever met Bob Moog, but like me, he liked the music produced on synthesizers.

  Bruce Gentry, KA2IVY

On 5/23/21 20:54, toby@telegraphics.com.au wrote:
Hi list,

Click for a nice surprise.

https://twitter.com/moogmusicinc/status/1396441500226101249

--Toby




Re: Happy birthday Bob Moog

Jeff Davis
 

I feel certain this is legitimate and sent with the best of intentions. However, for every one like that, I get at least 50 that are nothing more than phishing campaigns trying to get me to click on a malware link.

I’m wondering if there might be a safer way to make this available to the group?

Regards,
Jeff/N0DY

On May 23, 2021, at 5:54 PM, toby@telegraphics.com.au wrote:

Hi list,

Click for a nice surprise.

https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftwitter.com%2Fmoogmusicinc%2Fstatus%2F1396441500226101249&;data=04%7C01%7C%7C1158d649c4d74a50840308d91e4e853c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637574144847409180%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=k5pDK8VTiiYgwYBCTbz5JZFvHfXadv3Rkb0Xuo7waow%3D&amp;reserved=0

--Toby





Re: Happy birthday Bob Moog

Jim Ford
 

I don't do twitter, but I did have the fortune to meet Bob Moog at the NAMM show back in 2004 IIRC. Nice guy, and a darn shame that he passed away from cancer not too long afterward in 2005. RIP, Dr. Moog.

Jim Ford

------ Original Message ------
From: toby@telegraphics.com.au
To: TekScopes@groups.io
Sent: 5/23/2021 5:54:26 PM
Subject: [TekScopes] Happy birthday Bob Moog

Hi list,

Click for a nice surprise.

https://twitter.com/moogmusicinc/status/1396441500226101249

--Toby





Happy birthday Bob Moog

toby@...
 

Hi list,

Click for a nice surprise.

https://twitter.com/moogmusicinc/status/1396441500226101249

--Toby


Re: My eye sensitivity to blue-violet higher than normal

greenboxmaven
 

A very interesting discussion of human vision.  As far as films and phosphors, in the early 1950s, television programs were recorded for later replay by taking a motion picture of a CRT. The phosphor was  blue and UV with very short persistance, and the film was designed to perform best with it. A more modern and fairly easily obtainable similar CRT was used in the B&K "Television Anaylist" from the 1960s, which contained a flying spot scanner. The old test pattern, dot, bar, and crosshatch slides were provided for adjusting the convergence on old color TVs, for those who remember how. B&W photgraphic slides could also be used for images, and many TV shops used them for advertising on sets for sale.

    Bruce Gentry, KA2IVY

On 5/23/21 20:28, Harvey White wrote:

I can tell you what I've heard, without any particular authority, although my wife does have blue eyes, if that helps.

1) during WWII, the navy used ultraviolet lights (long wave) to illuminate phosphors on the decks of carriers.  Some few could see the lights, they invariably had blue eyes.  Apparently, people with blue eyes don't have a pigment that can block UV.

(ELK can see in the UV spectrum.  Wolves on snow blend in under normal light, when looked at under UV light, the wolves stand out.)

2) there is sufficient chromatic abberation in the human eye that blue and red focus at different distances.  Find a red/blue LED display, and you'll see that the blue seems to be more distant. Human vision is optimized for forest light, a rather yellowish green.

3) judging from the phosphors in the normal light fluorescent lamps, I'd guess that the different phosphors (more blue part, look and it seems to be yellow and blue) have different persistence, with blue being shorter than yellow.

Some things to think about:

1)  you're probably more sensitive to nighttime glare, the ones from the hopped up trucks with the low beams (if not high) that are almost blue in color.  A suggestion is to wear yellow tinted glasses.

2) as you get older, perhaps with cataracts, blue light scatters more, and will increase your sensitivity to glare.

3) it's easier to deal with blue sensitive photo film.  There's more energy in blue light, and the film can be handled under red light (dim, mind you).  Photographic paper is primarily blue sensitive if it's B&W.  (Orthochromatic).  There are orthochromatic (blue sensitive) and panchromatic films. Panchromatic films need to be handled under total darkness or the dimmest green (light sensitivity of the human eye) filter available.  Orthochromatic (Kodak fine grain positive release film, or kodalith, for instance) are safe under dim red light.

4) P11 phosphors were designed to match blue sensitive film, have a *very* short persistence for recording high speed events, and when viewed, will flicker a lot more.

Note that the normal phosphors are really in the yellow/green spectrum, with various persistences, so that they can be viewed under dim light.  The orange phosphors in some radar tubes (P12), were designed for command deck use under night conditions, where all the lighting was red.

Humans have a chemical called rhodopisin, (sp?) which increases the sensitivity of the rods (monochrome sensors) in the eye.  The center point of the eye has a lot of cones (color sensors) and not so much rods.  As you go out from the center of vision, you start to run out of cones, and get more rods.

In terms of vision, you look at what's in your central vision and you get high resolution color.  It's not a large high resolution area at all.  As you start with peripheral vision (rods) you get light sensitivity, sensitivity to movement, but no color. Translation:  SOMETHING IS TRYING TO SNEAK UP ON YOU, LOOK OVER HERE!!!

Since cones aren't very sensitive to light, they don't do well in the dark.  Rhodopsin is a chemical that takes a bit of time, but increases the sensitivity of the rods to light.  This is your "night vision".  Rhodopsin is ionized (read: destroyed) by blue light.  Blue light = no night vision, which is why astronomers use red light at night, and why ship's bridges are in red light when under night conditions.

Yet another reason why blue phosphors (P11) aren't used for low light level situations.  The P7 phosphor uses a blue layer behind a yellow layer.  The blue layer ultraviolet causes the yellow layer to glow with a long persistence.  Normally, for night time and radar, these are used with orange or yellow filters.

That's the history as I know it.

Harvey



On 5/23/2021 7:34 PM, Mark Vincent wrote:
I would like to know from anyone in this group that has a good educated to
known medical reason why I have a higher sensitivity and ease of viewing
light that is blue to violet so easily. I understand the rods and cones in
the eye and have enough medical knowledge to understand the Latin and Greek
terms of medical words. I have NO problem in seeing, focusing or any form
of eye strain on light that is in the high frequency part of the spectrum
of blue to violet, including indigo. I have always been this way. One note,
I do have blue eyes if that makes any difference. They are not the striking
steel blue that can look like blue lasers. Jean Harlow had steel blue eyes,
as an example of someone. Blue/ steel blue eyes in a male is far more
common in a male than a female.

Another thing I have with my eyes is that under 50/60 c/s flicker, I will
get a severe migraine and have the vision of "Mr. Magoo" within a few
minutes that takes a few hours to wear off after being removed from the
flickering light(s). For reading and general lighting, I prefer carbon
filament (Ferrowatt). Tungsten is fine.

Brenda mentioned having a RM565 scope with a blue trace (must be P11 by the
model)  that she gets eye strain easily. This is what finally made me ask
the group this. Others have mentioned how P11, blue, is nice briefly, not
for any time without the owner having eye strain and hard to focus on. I
have seen older posts on this group and other places online about people
saying blue trace is nice but annoyed by the hard to focus on and eye
strain within a few minutes. I have a couple of friends with blue eyes that
I asked about blue-violet phosphour. They said it is nice to glance at or
for a short time, not for any longer. They said they would prefer P1, P31,
etc, that is in the green area to look at for any length of time, a minute
or more. I will deal with P1 or P31. I find P2 the WORST to look at. The
blue part is fine, the cyan afterglow I find bilious. P7 is not as bad as
the afterglow is yellow with only the blue seen with a proper filter. Even
so, I will keep the intensity of a P7 low so as to only see the blue.

I know storage types need a P31 because of the secondary emission.
Something like the 2467/B or 7104 with the MCP could have been made with
other phosphours when made. The MCP does not care about the phosphour, only
acting like a photomultiplier.

I would like to find the P11 crts for my 556, 7603 and 465. The P31s in
them are in very good condition. I prefer the P11 because of the thinner
trace, ease on my eyes. and faster decay time. To find a 502A with P11 and
T317P11 for my 317 would be great. I know the 502A is 2mc capacity. The
7000 series I have, except for the 7934 and 7104, now have the P11 in them.
I do have good P31 types I removed from the scopes sitting around. I do
have a few of the 300, 400 and 500 series with the P11. If I can find
someone who can successfully rewind the high voltage transformers for the
older types, I would really like P11 for me 545B and 547 after getting
these transformers rewound. The only thing I have seen P16 in is a B&K 1076
analyst. That colour does not bother me at all. So far I have not seen a P5
although having any of these, 3AP5 for example, in place of a P1 would be
great. I know the decay time and light output of P5 is less and P11.

For any plant that has flowers, I do not mind any colour.

Mark








Re: My eye sensitivity to blue-violet higher than normal

Bruce Atwood
 

Cataracts not only scatter they are also yellow, that is minus-blue filters. I know that after having my OE lenses replaced all colors, but especially blues, were more vibrant. Have you had cataract surgery?


Re: My eye sensitivity to blue-violet higher than normal

Harvey White
 

I can tell you what I've heard, without any particular authority, although my wife does have blue eyes, if that helps.

1) during WWII, the navy used ultraviolet lights (long wave) to illuminate phosphors on the decks of carriers.  Some few could see the lights, they invariably had blue eyes.  Apparently, people with blue eyes don't have a pigment that can block UV.

(ELK can see in the UV spectrum.  Wolves on snow blend in under normal light, when looked at under UV light, the wolves stand out.)

2) there is sufficient chromatic abberation in the human eye that blue and red focus at different distances.  Find a red/blue LED display, and you'll see that the blue seems to be more distant. Human vision is optimized for forest light, a rather yellowish green.

3) judging from the phosphors in the normal light fluorescent lamps, I'd guess that the different phosphors (more blue part, look and it seems to be yellow and blue) have different persistence, with blue being shorter than yellow.

Some things to think about:

1)  you're probably more sensitive to nighttime glare, the ones from the hopped up trucks with the low beams (if not high) that are almost blue in color.  A suggestion is to wear yellow tinted glasses.

2) as you get older, perhaps with cataracts, blue light scatters more, and will increase your sensitivity to glare.

3) it's easier to deal with blue sensitive photo film.  There's more energy in blue light, and the film can be handled under red light (dim, mind you).  Photographic paper is primarily blue sensitive if it's B&W.  (Orthochromatic).  There are orthochromatic (blue sensitive) and panchromatic films. Panchromatic films need to be handled under total darkness or the dimmest green (light sensitivity of the human eye) filter available.  Orthochromatic (Kodak fine grain positive release film, or kodalith, for instance) are safe under dim red light.

4) P11 phosphors were designed to match blue sensitive film, have a *very* short persistence for recording high speed events, and when viewed, will flicker a lot more.

Note that the normal phosphors are really in the yellow/green spectrum, with various persistences, so that they can be viewed under dim light.  The orange phosphors in some radar tubes (P12), were designed for command deck use under night conditions, where all the lighting was red.

Humans have a chemical called rhodopisin, (sp?) which increases the sensitivity of the rods (monochrome sensors) in the eye.  The center point of the eye has a lot of cones (color sensors) and not so much rods.  As you go out from the center of vision, you start to run out of cones, and get more rods.

In terms of vision, you look at what's in your central vision and you get high resolution color.  It's not a large high resolution area at all.  As you start with peripheral vision (rods) you get light sensitivity, sensitivity to movement, but no color. Translation:  SOMETHING IS TRYING TO SNEAK UP ON YOU, LOOK OVER HERE!!!

Since cones aren't very sensitive to light, they don't do well in the dark.  Rhodopsin is a chemical that takes a bit of time, but increases the sensitivity of the rods to light.  This is your "night vision".  Rhodopsin is ionized (read: destroyed) by blue light.  Blue light = no night vision, which is why astronomers use red light at night, and why ship's bridges are in red light when under night conditions.

Yet another reason why blue phosphors (P11) aren't used for low light level situations.  The P7 phosphor uses a blue layer behind a yellow layer.  The blue layer ultraviolet causes the yellow layer to glow with a long persistence.  Normally, for night time and radar, these are used with orange or yellow filters.

That's the history as I know it.

Harvey

On 5/23/2021 7:34 PM, Mark Vincent wrote:
I would like to know from anyone in this group that has a good educated to
known medical reason why I have a higher sensitivity and ease of viewing
light that is blue to violet so easily. I understand the rods and cones in
the eye and have enough medical knowledge to understand the Latin and Greek
terms of medical words. I have NO problem in seeing, focusing or any form
of eye strain on light that is in the high frequency part of the spectrum
of blue to violet, including indigo. I have always been this way. One note,
I do have blue eyes if that makes any difference. They are not the striking
steel blue that can look like blue lasers. Jean Harlow had steel blue eyes,
as an example of someone. Blue/ steel blue eyes in a male is far more
common in a male than a female.

Another thing I have with my eyes is that under 50/60 c/s flicker, I will
get a severe migraine and have the vision of "Mr. Magoo" within a few
minutes that takes a few hours to wear off after being removed from the
flickering light(s). For reading and general lighting, I prefer carbon
filament (Ferrowatt). Tungsten is fine.

Brenda mentioned having a RM565 scope with a blue trace (must be P11 by the
model) that she gets eye strain easily. This is what finally made me ask
the group this. Others have mentioned how P11, blue, is nice briefly, not
for any time without the owner having eye strain and hard to focus on. I
have seen older posts on this group and other places online about people
saying blue trace is nice but annoyed by the hard to focus on and eye
strain within a few minutes. I have a couple of friends with blue eyes that
I asked about blue-violet phosphour. They said it is nice to glance at or
for a short time, not for any longer. They said they would prefer P1, P31,
etc, that is in the green area to look at for any length of time, a minute
or more. I will deal with P1 or P31. I find P2 the WORST to look at. The
blue part is fine, the cyan afterglow I find bilious. P7 is not as bad as
the afterglow is yellow with only the blue seen with a proper filter. Even
so, I will keep the intensity of a P7 low so as to only see the blue.

I know storage types need a P31 because of the secondary emission.
Something like the 2467/B or 7104 with the MCP could have been made with
other phosphours when made. The MCP does not care about the phosphour, only
acting like a photomultiplier.

I would like to find the P11 crts for my 556, 7603 and 465. The P31s in
them are in very good condition. I prefer the P11 because of the thinner
trace, ease on my eyes. and faster decay time. To find a 502A with P11 and
T317P11 for my 317 would be great. I know the 502A is 2mc capacity. The
7000 series I have, except for the 7934 and 7104, now have the P11 in them.
I do have good P31 types I removed from the scopes sitting around. I do
have a few of the 300, 400 and 500 series with the P11. If I can find
someone who can successfully rewind the high voltage transformers for the
older types, I would really like P11 for me 545B and 547 after getting
these transformers rewound. The only thing I have seen P16 in is a B&K 1076
analyst. That colour does not bother me at all. So far I have not seen a P5
although having any of these, 3AP5 for example, in place of a P1 would be
great. I know the decay time and light output of P5 is less and P11.

For any plant that has flowers, I do not mind any colour.

Mark





Re: My eye sensitivity to blue-violet higher than normal

Jim Ford
 

Interesting, Mark! I seem to be the opposite; I can focus on reds and oranges much better than blues and greens. Longer wavelengths are better for me. Any blue lighted signs at night are all but illegible.
Been that way for at least 40 years. My eye color is greenish gray.

I've not experienced eye fatigue with any of the CRTs on my instruments, but then I don't spend hours upon hours looking at any of them (not so far, anyway). I have green phosphor Tek 5110N/D10, Tek 7603, and HP 8566 and a blue phosphor Tek 7904.

Good luck tracking down and avoiding the eyestrain issues.

Jim Ford

------ Original Message ------
From: "Mark Vincent" <orangeglowaudio@gmail.com>
To: TekScopes@groups.io
Sent: 5/23/2021 4:34:53 PM
Subject: [TekScopes] My eye sensitivity to blue-violet higher than normal

I would like to know from anyone in this group that has a good educated to
known medical reason why I have a higher sensitivity and ease of viewing
light that is blue to violet so easily. I understand the rods and cones in
the eye and have enough medical knowledge to understand the Latin and Greek
terms of medical words. I have NO problem in seeing, focusing or any form
of eye strain on light that is in the high frequency part of the spectrum
of blue to violet, including indigo. I have always been this way. One note,
I do have blue eyes if that makes any difference. They are not the striking
steel blue that can look like blue lasers. Jean Harlow had steel blue eyes,
as an example of someone. Blue/ steel blue eyes in a male is far more
common in a male than a female.

Another thing I have with my eyes is that under 50/60 c/s flicker, I will
get a severe migraine and have the vision of "Mr. Magoo" within a few
minutes that takes a few hours to wear off after being removed from the
flickering light(s). For reading and general lighting, I prefer carbon
filament (Ferrowatt). Tungsten is fine.

Brenda mentioned having a RM565 scope with a blue trace (must be P11 by the
model) that she gets eye strain easily. This is what finally made me ask
the group this. Others have mentioned how P11, blue, is nice briefly, not
for any time without the owner having eye strain and hard to focus on. I
have seen older posts on this group and other places online about people
saying blue trace is nice but annoyed by the hard to focus on and eye
strain within a few minutes. I have a couple of friends with blue eyes that
I asked about blue-violet phosphour. They said it is nice to glance at or
for a short time, not for any longer. They said they would prefer P1, P31,
etc, that is in the green area to look at for any length of time, a minute
or more. I will deal with P1 or P31. I find P2 the WORST to look at. The
blue part is fine, the cyan afterglow I find bilious. P7 is not as bad as
the afterglow is yellow with only the blue seen with a proper filter. Even
so, I will keep the intensity of a P7 low so as to only see the blue.

I know storage types need a P31 because of the secondary emission.
Something like the 2467/B or 7104 with the MCP could have been made with
other phosphours when made. The MCP does not care about the phosphour, only
acting like a photomultiplier.

I would like to find the P11 crts for my 556, 7603 and 465. The P31s in
them are in very good condition. I prefer the P11 because of the thinner
trace, ease on my eyes. and faster decay time. To find a 502A with P11 and
T317P11 for my 317 would be great. I know the 502A is 2mc capacity. The
7000 series I have, except for the 7934 and 7104, now have the P11 in them.
I do have good P31 types I removed from the scopes sitting around. I do
have a few of the 300, 400 and 500 series with the P11. If I can find
someone who can successfully rewind the high voltage transformers for the
older types, I would really like P11 for me 545B and 547 after getting
these transformers rewound. The only thing I have seen P16 in is a B&K 1076
analyst. That colour does not bother me at all. So far I have not seen a P5
although having any of these, 3AP5 for example, in place of a P1 would be
great. I know the decay time and light output of P5 is less and P11.

For any plant that has flowers, I do not mind any colour.

Mark





My eye sensitivity to blue-violet higher than normal

Mark Vincent
 

I would like to know from anyone in this group that has a good educated to
known medical reason why I have a higher sensitivity and ease of viewing
light that is blue to violet so easily. I understand the rods and cones in
the eye and have enough medical knowledge to understand the Latin and Greek
terms of medical words. I have NO problem in seeing, focusing or any form
of eye strain on light that is in the high frequency part of the spectrum
of blue to violet, including indigo. I have always been this way. One note,
I do have blue eyes if that makes any difference. They are not the striking
steel blue that can look like blue lasers. Jean Harlow had steel blue eyes,
as an example of someone. Blue/ steel blue eyes in a male is far more
common in a male than a female.

Another thing I have with my eyes is that under 50/60 c/s flicker, I will
get a severe migraine and have the vision of "Mr. Magoo" within a few
minutes that takes a few hours to wear off after being removed from the
flickering light(s). For reading and general lighting, I prefer carbon
filament (Ferrowatt). Tungsten is fine.

Brenda mentioned having a RM565 scope with a blue trace (must be P11 by the
model) that she gets eye strain easily. This is what finally made me ask
the group this. Others have mentioned how P11, blue, is nice briefly, not
for any time without the owner having eye strain and hard to focus on. I
have seen older posts on this group and other places online about people
saying blue trace is nice but annoyed by the hard to focus on and eye
strain within a few minutes. I have a couple of friends with blue eyes that
I asked about blue-violet phosphour. They said it is nice to glance at or
for a short time, not for any longer. They said they would prefer P1, P31,
etc, that is in the green area to look at for any length of time, a minute
or more. I will deal with P1 or P31. I find P2 the WORST to look at. The
blue part is fine, the cyan afterglow I find bilious. P7 is not as bad as
the afterglow is yellow with only the blue seen with a proper filter. Even
so, I will keep the intensity of a P7 low so as to only see the blue.

I know storage types need a P31 because of the secondary emission.
Something like the 2467/B or 7104 with the MCP could have been made with
other phosphours when made. The MCP does not care about the phosphour, only
acting like a photomultiplier.

I would like to find the P11 crts for my 556, 7603 and 465. The P31s in
them are in very good condition. I prefer the P11 because of the thinner
trace, ease on my eyes. and faster decay time. To find a 502A with P11 and
T317P11 for my 317 would be great. I know the 502A is 2mc capacity. The
7000 series I have, except for the 7934 and 7104, now have the P11 in them.
I do have good P31 types I removed from the scopes sitting around. I do
have a few of the 300, 400 and 500 series with the P11. If I can find
someone who can successfully rewind the high voltage transformers for the
older types, I would really like P11 for me 545B and 547 after getting
these transformers rewound. The only thing I have seen P16 in is a B&K 1076
analyst. That colour does not bother me at all. So far I have not seen a P5
although having any of these, 3AP5 for example, in place of a P1 would be
great. I know the decay time and light output of P5 is less and P11.

For any plant that has flowers, I do not mind any colour.

Mark


Re: Has anyone replaced the Graticule lights with LEDs?

Harvey White
 

LEDs can be gotten in different dispersions, some, for instance, I think at 130 degrees.  If you have a 3D printer, you might be able to make a light shroud depending on your needs.  If you can do PC boards, then I could recommend a 3 color LED.  How to profitably control it is another matter.  Otherwise, pick a color depending on what you want.

It might get close to an incandescent lamp.

Harvey

On 5/23/2021 5:15 PM, DaveH52 wrote:
In a few days, I'll be disassembling my 2465 again to install a replacement module for U800. Since it will be totally disassembled, I'm seriously considering replacing the graticule lamps with red LEDs. I plan on 'frosting' the tops so the light will be more diffused. It worked well for the meter on my Kenwood TS-440, except I used white LEDs for that.





Re: Has anyone replaced the Graticule lights with LEDs?

Eric
 

I have updated the album on the group with some more shots of the LED mod to a 7603. I have the 7704A at work so I will have to get some pictures Monday. The second 7603 has the ND filter on it. I only have 1 clear. My 7704A I believe has TEK blue filter on the face. The LEDS used a 3 X 5mm ULTRA bright white from adafruit. I need to open the here in a little to find out what the dropping resister value is. But the LEDs I believe have a 2.5V forward voltage and I think the lamp supply is a 5V rail so you only need to drop about 2.5 Vdc with the resister. Max current for the LEDs is 20mA. If there is interest I can shoot some video on it. Of note the scope intensity is only just over 1/4 ON so the tube is not being driven hard at all.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Clark Foley
Sent: Sunday, May 23, 2021 3:49 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Has anyone replaced the Graticule lights with LEDs?

Hi Dennis,
You have an interesting upgrade idea. I have not made such a conversion to LEDs for the graticule, but I have struggled with non-uniform illumination many times for promotional photographs. We always used a flash for the close-up photos.
I think that you could overcome the directional nature of the LEDs by abandoning the graticule diffuser assembly and substituting an array of closely spaced-surface mounted LEDs (a.k.a. light bar). Perhaps one LED aligned with each grat line. The nice thing about the four-holer 7k mainframes is that there is a little bit of space above the face plate to add a second illuminator. Grat lights above and below with help with the gradient from bottom to top and the closely spaced LEDs will reduce the old bulb hot spots.
I realize that this is no help at all, but it fun thinking about it.

Clark

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