Converting from CRT to LCD or anyone know about video signal

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Re: Converting from CRT to LCD or anyone know about video si

Postby Jerry » Mon Mar 07, 2011 3:44 am

The unit does have a feature where it dims to about half brightness after 5 minutes if inactivity. What I might do is install a small switch on the back so I can turn off the CRT without turning of the unit and loosing position. It has spots for two more axis on the back but they drilled holes where the connectors would solder in to the boards. But it is very easy to tell which traces are what since they laid them all out identical. Got two of the connectors coming and will patch them in. I was hoping to add one more scale to my compound but I dont think I can make one fit. Possibly if I get one of the ultra slim scales out there and get creative. Next project is to make a mpunt to hold the thing.

This is just about the last CRT I own. Gave my parents my old 32" tv as well as my nice LaCie 22" monitor. Everything here is LCD now.
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Re: Converting from CRT to LCD or anyone know about video si

Postby Doug Coulter » Mon Mar 07, 2011 1:01 pm

I still have a few CRT things around. But I don't use most of them, like old CRT computer monitors - ecch. I have a bunch in the tube collection (tektronix and others) which I don't have the matching gear for, and a couple crt type scopes which I do still use some. I sure wish I could find those custom hybrid chips used in the vertical part of a 465 circuit, as I just plain love those things -- and that's what fails. Tektronix says "just buy a new scope" which I did, but not from them -- they are no longer the best and don't compete on price either -- GW Instek blows them off both ways (that's where the digital screen shots I post come from, I got two of those guys).

I'm beginning to think that their main value might be the nicely made lensing system in there -- cut off the neck, save the "gun" and maybe replace the cathode with an ion source to get nice focused ion beams or something similar. It's not like the innards aren't very nicely and precisely made, just that as a display, the couple of 22" LCD's I'm sitting in front of really rock by comparison -- and use much less power in the bargain. In fact, there's three (big ones, plus 2 smaller) in the room right now -- my wife is watching TV on one. No going back once you get used to that level of display quality. But I kinda hate to see things that were really sweet in some sense just die out too. Rapp made a microscope off an electron gun in a vidicon for example -- a good re-purposing.
Of course to do that really well, you'd have to replace the mixed-oxide cathode with something else so it could stand air exposure.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Converting from CRT to LCD or anyone know about video si

Postby Jerry » Mon Mar 07, 2011 1:24 pm

I cant remember which but Tek either spun off or sold off their hybrid circuits division to either Maxim or Maxtek. They cant even get the parts they used to make. I have heard of them buying old machines to get parts to repair others under contract. I dont know whether this is true or not.

We did have one of thier newer scopes with the built in logic analyzer. Real nice unit. Bad thing is it took several minutes to boot.
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Re: Converting from CRT to LCD or anyone know about video si

Postby Doug Coulter » Mon Mar 07, 2011 2:36 pm

The built in analyzer was pretty cool. One of our consulting customers bought one for a hardware engineer there we really liked (both). He could make that thing do some amazing tricks, but...learning curve very steep, a lot more than the old type logic analyzer I was used to (and still own someplace). It especially excelled in doing things with serial type streams. But the darn thing cost like half a year's pay too. I paid about 1k for the 2.5 ghz 4 ch GW Instek (which has some of that stuff) and under 400 for a 100mhz 2 ch one, both of which are plenty nice enough for my uses here.

Nothing will ever beat the old tektronix trigger circuits though -- sadly, that includes their own new products.

And, there's linux tools for Insteks that integrate screen shots, raw data, settings (both ways), and inputs to things like GnuPlot and Octave if you want that -- all free. Some is a little clunky, but it all works well enough to get a job done (typical of the linux tool box approach, it's pretty solid). Of course, I can't stream 4 channels of 2.5ghz sample rate over USB to the PC (which couldn't eat that even if I could) but it can take plenty of snapshots quick. Scope does things like FFT's and go-nogo waveform tests, which is enough for me as I'm not trying to design a new ethernet MAC or PHY chip or anything like that, just fix things, test sensors, and look at stuff going on in the fusor mostly.

Used to be you needed all that junk just to get an 8080 going at all. Now, you just get a PIC -- add 5v and code, and it all works, no picky clock waveform duty cycle issues and all that crap.
Or you get an eval board and use it to do the project, realizing that while you overpay for that -- it saves you so much time that if your time is worth diddly, you make out doing that anyway.

But if all I'm doing is for example, looking at some unwanted feedback in my new 3He preamp that creates some bobble on the signal, heck, any scope does fine. The digitals have one big advantage of holding the last trigger on screen till the next one happens, which is good when my puny homebrew neutron source only counts the tube about once every 3-4 seconds, don't always want to do this kind of work next to a running fusor, after all.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Converting from CRT to LCD or anyone know about video si

Postby Jerry » Sat Mar 12, 2011 11:02 pm

Got it installed on the last last night, made a stand out of some extruded aluminum we had lying around at work that was not compatible with any of out 80/20 stuff.

Todays little project. A guy on one of the other boards I am on had a Accu-rite Microscale which I got from him. Had the same plug even. Looking at the drawings I was able to determine it wouid just fit on the compound.

Got the scale today, cut it down in length and made a mount. Fits perfectly! I still can access the nut for the compound too.

Cutting the scale down was interesting. Not as easy as the larger, older KC scales. I had to cut through it with the bandsaw, glass and everything (Glass cuts pretty OK, really.) Then I went in with a diamond cone bit on the dremel and cut the glass back for the end cap and then chewed away the extra aluminum so the end cap would fit back on. I drew up the oval screw hole and popped it in the cnc mill and cut the holes.

The DRO unit has a vectoring option where you set the angle of the compound to 29 or 29.5 degrees and it will show you the distance moved in relation to the X axis. Very handy!

Image
Anilam Superwizard on Monarch 10ee compound by macona, on Flickr

Image
Anilam Superwizard on Monarch 10ee by macona, on Flickr
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Re: Converting from CRT to LCD or anyone know about video si

Postby Doug Coulter » Mon Mar 14, 2011 7:56 pm

Shuuur is purty. Nice big crisp display...Be fun to work with!
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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