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8560E New to Me: Some Issues & Questions
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On Tue, 6 Nov 2018 at 10:14 Rick Boswell <frboswell@...> wrote: Search for album in Photos with key words Agilent 8560. Or just click the album link:?/g/HP-Agilent-Keysight-equipment/album?id=77464.? |
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Since I posted my question, I have received several examples, and
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I feel pretty confident the VGA resolution is going to look nice on the 8566B... There can be no doubt that Xu Wang has done a wonderful thing for owners of these old CRT based instruments. I like to support the small guys that do these niche market adventures... so regardless of whether or not I keep the Nuscope-8 on my 8566B, I feel good about the expense. -Chuck Harris Scott McGrath wrote: Ah with an 8566x I can see where there would be a difference between a ¡®good¡¯ CRT and the newscope. |
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Speaking of being "portable", I still remember lugging an 8568 to the penthouse of "Tower Plaza", a 28 story building in downtown Ann Arbor Michigan on numerous occasions back in the 80's to work on the repeaters our radio club had up there.? It was never anything I looked forward to!
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But it sure helped find a lot of gremlins! Daun On 11/6/2018 3:23 PM, Scott McGrath wrote:
Ah with an 8566x I can see where there would be a difference between a ¡®good¡¯ CRT and the newscope. --
Daun E. Yeagley II, N8ASB |
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Yes, but which resolution panel is the video using, and which
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resolution are you using? He sent me a high resolution picture of the VGA model, and it is pretty good, but when I did the same simulation using the real deal, it was better... just green. I have my fingers crossed. Mine will be here in a couple of days. I will report my findings, if I can... -Chuck Harris Orin Eman wrote: On Tue, Nov 6, 2018 at 10:55 AM Chuck Harris <cfharris@...> wrote:The big difference between what Xu Wang has seemes to have done, |
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On Tue, Nov 6, 2018 at 10:55 AM Chuck Harris <cfharris@...> wrote: The big difference between what Xu Wang has seemes to have done, Xu gives you the choice of anti-aliased or not.? On his demo video here:? At 0:27 is his anti-aliased display and at 0:37 is the original monochrome emulation with stair-steps visible.? To my eyes, there is no competition and I use the NewScope mode. On reviewing this video, it also shows the zero-frequency span capabilities.? It works really well and is much better than the original display at 1uS sweep time.? The trace on an original display would be dim, unstable and did not start at the left edge of the graticule. |
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True, and with the 8560E, it isn't even really lower resolution,
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but with the 8566B, it is very much so. Measurement accuracy is hardly the problem, appearance is the problem, and that is of course subjective. The cursors will still hug the waveform at the higher resolution level, and will still be read out to the ultimate accuracy of the 8566B. We will see. I am hoping that the flashy display with all of its colors will make it just seem normal and right. The big difference between what Xu Wang has seemes to have done, and what is done in many graphics situations is he is drawing full intensity lines of single pixel width. When the line is slightly off vertical, or horizontal, you see a stair step approximation. If there were a little more graphics power in use, the traces could be made wider, with variable brightness across their width. So, even though they are wider, they would appear to be smoother and narrower. An example of this that you may have seen on your computer happens when you scan a document. If you use the line-art setting, where the pixels are either on, of off, you need a fairly high resolution to avoid seeing artifacts on the text... say 300 to 600 dpi. If, however, you use grayscale, you can get something that appears to be higher resolution while using only a paltry 75 dpi. -Chuck Harris Orin Eman wrote: On Tue, Nov 6, 2018 at 7:53 AM Scott McGrath <scott@...> wrote:All I can say is the Newscope screen is FAR easier to read than the |
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On Tue, Nov 6, 2018 at 7:53 AM Scott McGrath <scott@...> wrote: All I can say is the Newscope screen is FAR easier to read than the original CRT screen, Xu has done a remarkable job at anti-aliasing the trace and I'm well pleased with the beta version I have in my 8568A. As for the lower resolution, if I'm reading a value, I'd use a marker anyway... ? |
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All I can say is the Newscope screen is FAR easier to read than the original CRT screen,
Yes there is a theoretical downgrade from a 1K x 1K Vector screen. And if someone had a brand new tube in a freshly aligned instrument im sure we could see the difference But the Newscope looks as good as some of the brand new Keysight stuff. Including my FieldFox microwave analyzer Content by Scott Typos by Siri |
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I apologize for poaching on this thread with my really 8566B, Newscope-8
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questions. I talked with Xu Wang, of Simmconn, and basically, he will sell the Newscope-8, with XGA display, only if you order qty 5+. The display is an industrial model, and costs him almost as much as the total price he charges for the VGA model Newscope-8 ($499). He said that it was very rare that he even got an order for the more expensive XGA model. I mentioned the cheap 7" XGA LCD's that are all over the place for $80, and he said the problem is they are wide format, will not readily fit the bezel for the 85662A display unit, and are too dim. The WXGA models are also too wide, and too dim. He chose not to ramp up production on them for that reason. So, he only stocks the VGA (640x480) resolution LCD's. However, on looking at high resolution pictures of that display, I ordered anyway. He has diddled with the character fonts to optimize them for VGA resolution, so they are not a problem, but I do worry about the jaggies that show up in the signal display. They are about 2x what is viewed on the original CRT display. He could have done better by some video processing that would fuzz out the display lines over about 3 pixels, instead of 2. He also mentioned that he was not planning to order any more of the Newscope-8 control boards when his current stock runs out... It would appear we are not buying enough to keep him interested in selling that model. I ordered a VGA model Newscope-8 last night. I will try it without doing any permanent damage to my 85662A display unit, as my CRT is in like new condition, and doesn't really need replacing. If I like it, I will keep it. If not, I will use it to repair an 8566/68 that comes with a bad CRT. -Chuck Harris John Miles wrote: Regarding the Newscope upgrades, they now seem to only sell the VGA640x480 is the correct resolution for an 856xA/E portable model. That's what was used in the later 8560EC series. However, it's best to use a 1024x768 XGA panel to replace the CRT in an 85662A-based benchtop model (8566/8567/8568). The latter have 1001 points of display resolution while the portables only have 601. |
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OK - after some fooling around, have created an album of two photos showing 8560E screen at max intensity (255) and at a lower setting (214) which is the intensity level just before the text dims out completely. Graticule and signal traces remain clear and sharp at much lower intensity settings. Search for album in Photos with key words Agilent 8560.
RB |
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On Tue, Nov 6, 2018 at 01:35 AM, John Miles wrote:
640x480 is the correct resolution for an 856xA/E portable model.John, Thanks for clarifying.? The CRT probably has what is known as cathode poisoningSam, Yes - a distinct possibility. An earlier post here also linked to the KE5FX post on CRT restoration. What I am seeing on my screen does not closely match any of the KE5FX photos, but perhaps this is irrelevant. Happy to post some photos if I can figure out how to do that here. RB K8EZB ? |
Regarding the Newscope upgrades, they now seem to only sell the VGA640x480 is the correct resolution for an 856xA/E portable model. That's what was used in the later 8560EC series. However, it's best to use a 1024x768 XGA panel to replace the CRT in an 85662A-based benchtop model (8566/8567/8568). The latter have 1001 points of display resolution while the portables only have 601. For some reason SimmConn's page for the 85662A display says that XGA resolution requires a special order. I guess there's some sticker shock involved, because I can't think of any other reason not to go with XGA when upgrading the big-iron hardware. -- john, KE5FX |
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IIRC you said that the instrument has over 60,000 operating hours on it. It may be safe to assume that the unit still has the original CRT in it. The CRT probably has what is known as cathode poisoning. This is where the cathode is contaminated and the crt may not have the electron emission required to do fast writes required on curves. Can you post some pictures of your CRT showing the anomalies. Have a look here for some ideas: (this is for a HP8566 but the CRT drive concepts are the same vector approach). Sam W3OHM --? Sam Reaves
ARS W3OHM
Owner and Moderator of:
LeCroy_Owners_Group on Yahoo! Groups LeCroy Owners Group on Groups.io (backup group) |
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On Mon, Nov 5, 2018 at 01:54 PM, Scott McGrath wrote:
It IS a CRT problem, ?the first signs of cathode poisoning are the text characters going soft. Scott, ? Thanks for your response, and especially the link to ¡°CRT Restoration for the Brave¡±. While the appearance of my CRT is decidedly different from any of the photos at this link, as you suggest, cathode poisoning may well be the culprit. I have already made the mental commitment to go to the SimmConn/New Scope LCD kit but since my 8560E was acquired as a learning aid, I¡¯d like to see what I can learn from some additional troubleshooting. My plan of attack: 1.?????? Remove the instrument from the case and identify what is what, including the location of the controls associated with the Display Adjustment procedure in the SM. 2.?????? Carefully attempt to perform the DA procedure. (I say ¡°carefully¡± as this is entirely new ground for me). 3.?????? Depending on the results of step 2 above, consider attempting the restoration procedure outlined in the link. 4.?????? Install the SimmConn/New Scope kit once my confidence level is sufficiently high. (I emphasize ¡°confidence¡± as I have looked at several of the SimmConn kits and the one for the 8560E is more complex than some of the others. It requires installing five DIP sockets on top of existing soldered-in DIP ICs and soldering these to the IC pins. Not brain surgery but technique sensitive for sure. (In a much earlier life I had a job as an electronics tech at Gould/Brush Instruments troubleshooting and repairing strip chart recorders on the production line. They insisted on mil quality soldering, so I can hopefully call up those skills one more time. However, IC¡¯s were still some years off at that time.) ? If I screw this up I can likely sell the SA as a ¡°parts¡± unit for more than I paid for it given what I am seeing on eBay. Progress reports to follow ¡ slowly! RB |
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Regarding the Newscope upgrades, they now seem to only sell the VGA
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LCD display. 640x480 seems to me a bit coarse for replacing a 1024x1024 vector display. Has anyone tried it? Is it an upgrade, or a downgrade from a working original CRT? What about things like speed, brightness, ??? -Chuck Harris Scott McGrath wrote: It IS a CRT problem, the first signs of cathode poisoning are the text characters going soft. The characters are drawn as vectors not as a bitmap and a raster scan. Hence the distortion seen on the screen as the electron gun can longer generate a tight beam of electrons. |
¿ªÔÆÌåÓýIt IS a CRT problem, ?the first signs of cathode poisoning are the text characters going soft. ? The characters are drawn as vectors not as a bitmap and a raster scan. ? Hence the distortion seen on the screen as the electron gun can longer generate a tight beam of electrons.The HP CRT¡¯s were incredible to look at when new but the design of the tube is unique to HP and it has a fatal flaw which shows up after years of service. ? Unfortunately NOS tubes and good used tubes are approaching and in many cases surpassing the price of the Newscope upgrades. I think you will find that after doing the 15 page CRT alignment process that your 8560E will have the same symptoms as before. Here¡¯s an article from another member here describing the failure? Content by Scott Typos by Siri |
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On Mon, Nov 5, 2018 at 09:42 AM, tmillermdems wrote:
Have you done the 7 pages of adjustments for the display calibration?Not yet. Have not yet removed the case - trying to think through the possibilities before I start changing things. I have the manual, but I don't have the arsenal of test gear recommended in the manual and am probably not going to have this gear in the foreseeable future. I may resort to winging it a bit. Are there differences in brightness of horizontal vs. vertical strokes? I'd be quite curious what you find.No - straight lines, whether vertical, horizontal or diagonal are uniformly bright. RB ? |
Sam Reaves
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