What's new Labguy?
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I have been on hiatus from projects lately. Discovered a free schematic capture and PCB layout program that actually works. That is what has kept me preoccupied all this time. It's called the [KiCad EDA Software Suite]. It took only a couple of days for me to master the basics and less than a week to feel confidant with this tool. Open source. Free is a good price. Check it out for yourself. It's certainly no $8,000 pro package. But, I have yet to find anything to complain about. KiCad is simple in concept and easy to learn and use.
On the last round of experiments, with my electrostatic deflection amplifer, I somehow managed to burn out the amplifier. Hope to get back on that as soon as possible. I have some new ideas to persue that should improve the amplifier's bandwidth. Let's hope. The goal is to get to where it passes at least 4MHz. Currently, a 15.734KHz sawtooth can only generate a maximum scan width that is half of what the vertical channel can show for the same input drive level. This places true 3db bandwidth at around 75KHz! Since I'd like to use the same amplifier for the video as well, I am shooting for 4MHz bandwidth. New transistors perhaps?
Development of my electrostatic scan amplifier continues. The two Threeneurons DC-DC converter kits arrived. It took a little over half an hour to assemble both of them. They both worked first time. Next day, two more DC-DC converters arrived. These were the prebuilt units and both of them worked perfectly as well. A CAD schematic of the entire board is currently being produced as well as a printed circuit board layout. The entire amplifier will operate from a single +12 volt input at right around 250mA. Two channels of medium bandwidth will lift a single ended zero to three volt input up to a differential output of zero to 300 volts.
When I designed the Tiny TV mark 2 PCB, I discovered that the library part for the LM319 dual comparator had errors. Since then, I have found that common NPN transistors are also hosed in the libraries. I have no explanation for this. The MJE340 has the base and collector pins swapped. When I re-edited the entry, fixing the pins, the next time it loaded, the emmiter and base pins were swapped. It looks fine in the library. It's shit when loaded to the board. Not bad for a $15,000 POS *so called* professional design tool.
The work around is to create my own schematic symbols and PCB footprints directly and kiss off the standard libraries. I was able to finally produce a usable version of the MJE 340 that is pinned into a 3 pin 100mil spaced header footprint so the transistors can be loaded into the board in the upright posistion. The 2N3904s were finally fixed by loading 2N2222As on the schematic, editing their symbol to include the TO92 footprint used by the 2N3904 and casting 2N2222s onto the board. I will hand edit the line entries to 2N3904s when I manually process the Bill of Materials.
If anyone who reads this blog knows anything about Kicad, please write to me. I am trying to learn this program in a vacuum. Everyone says they want to help. But, when you actually call on them.... crickets. I may as well be living on the back side of an asteroid ten AUs from Earth!
I finally created a page devoted to the electrostatic scan amplifier for my cathode ray tube projects. Got the 300 volt deflection amplifiers working very well now. I also installed a miniaturized high voltage DC-DC conveter to eliminate the old vacuum tube power supply. Read all about it on the [Electrostatic Scan Amplifier] project page.
Tested the following cathode ray tubes with the new electrostatic scanning amplifier so far: 2BP1, 2BP11, 3RP1A, 3JP2, 3JP7, 3JP12, 5DEP1, and 5UP1.
Awaiting the arrival of two more of the small DC-DC converters from Ebay. Will produce a third, cleaned up, deflection amplifier board with all the features installed properly. In other words, the finished product. It will include a second smaller DC-DC converter to produce -12 volts from +12 volts. At that point, the entire scan board runs on a single +12 volt power supply. Sweet!
As for the James Millen Oscilloscope in the last update, the vertical noise problem is in the scope. Not in my amplifier afterall. I suspect a bad capacitor. That's not a surprise.
Work on miniature cathode ray tubes continues. I recently obtained a very rare James Millen & Co. model 90901 one inch oscilloscope module. It utilizes the Cossar 1CP1 one inch cathode ray tube. Fired up the 90901 and tested it. It works as well sa the day it was manufactured 55 years ago. [See it here]. What a cool project! See more on the Electronics Projects pages of this site.
Awesome news! Labguy's Tek 744A digital oscilloscope is finally repaired and back in action! If you recall, it died the day before the Christmas break began. The plan was to crank out the video monoscope during that two week period. The failure of my oscilloscope was a shot to the head. Not only was it now impossible to complete the project, my normal depression took over and no project has been appealing to me since then.
Now, we can try to even the keel of the good ship Labguy's World and get back to business. I would like to extend my personal thanks to Johnny and every one else at [Top Dog Test] for their excellent service. Thank you all, and keep up the great work!
I have reworked the [personal contact and info page] for the site. Removed a lot of dead wood subject matter and cleand up the badly written HTML of that much older page. I hand write these web pages using Windows Notepad. So depending on what era from whence they originate, the coding quality and appearence of any individual pages may vary. The contact page is now reworked to my present level of HTML coding skills. More or less...
Happy New Year!
Another year is upon us. There will be more extinct video info and exciting projects to come this year.
Just got another one inch CRT. A 1CP1 manufactured by Cossar in England in 1969. Functionally similar to the RCA 913.
To see years 2007 to 2014 What's New pages, [CLICK HERE]. Scroll to the bottom of each What's New page to find a link to the previous year at the bottom.
Created: January 2, 2015, Last updated: January 29, 2015