Rebuilding my old analog console

[Kevint]

Purchased 16ea of AD633's

[Kevint]

I believe the AD633's will add the ramp effect. So, while I wait for parts to build the breadboard, I noticed on the drawings provided by Laseris it shows the FXCY, could we discuss how that works. I saw it in the CYGN posts as the fixed cycloid board. I think that would be a good addition to the project.

[Greg]

I believe the AD633's will add the ramp effect. So, while I wait for parts to build the breadboard, I noticed on the drawings provided by Laseris it shows the FXCY, could we discuss how that works. I saw it in the CYGN posts as the fixed cycloid board. I think that would be a good addition to the project.

I expect you will find the use of the AD633 for amplitude modulation delightful. There is a too good to be true ramp generating circuit which appears in both the CYGN-A and CYGN-B schematics. It is actually called the colormod2 circuit, but it is just as useful for AM effects. See CYGN-B page 26 for the exciting moment when laserist reveals the secret part of this circuit that is not on the schematic.

[Kevint]

I believe this is what you are referring to - From Laserist: "It's a clever little circuit. There's a 100k pot across the diodes, and the wiper from that pot is connected to the wiper of a 10k pot one side of that pot is connected to the "square wave" output and the other side is connected to ground. (Looking at the schematic I don't see how the "square wave" output could actually be a square wave.) The remaining pin is the color mod II signal. The 10k pot is the freq. and the 100k pot is the symmetry for the ramp. Run the color mod signal across a 10k pot to ground and the wiper controls the color mod II gain."

Agree, this would be a wonderful signal generator for the AM ramp circuit. Is the schematic of the color mod II circuit available? I would like to build and play around with it.

Awesome input Greg - thank you.

[ronhip]

If it helps, I can supply the specs for the Fixed Cycloid board (FXCY) as it existed in the 6B projector. Enjoy!

Ron

I believe the AD633's will add the ramp effect. So, while I wait for parts to build the breadboard, I noticed on the drawings provided by Laseris it shows the FXCY, could we discuss how that works. I saw it in the CYGN posts as the fixed cycloid board. I think that would be a good addition to the project.

[Greg]

Ron, I'm sorry. I forgot to send better photos of the osmium ingot. I have been enjoying your super high quality content, and saw the osmium video posted recently. How did you get such a clean view of the pellet rotating without reflected clutter?

[Kevint]

You guys are totally awesome. Thank you so much Ron. You know, I will not be able to sleep tonight because I will have schematic on the brain. This is great stuff.

[Kevint]

OK, I can't sleep.

Simplistically, to build just the fixed cycloid portion. Build 3 oscillator sections A, B and C with the appropriate resistor values listed. These 3 oscillators provide the XY inputs to produce a circle, square, triangle, and star. The outputs from these oscillators go to the corresponding summing resistors in the center of the page, outputs 15 - 22 I believe to go a rotary switch. Depending on the switch position, the XY signals for a circle, square, triangle or star are sent to the summing op amps inputs 11 and 13. From there the X out and Y out signals could be sent to scanner amps and the selected image displayed. This is great.

The circuit on the right and the 2 below it, say they are for the KQO. From the CYGN tread this is the "Keyed Quadrature Oscillator" I have no idea what it does. The circuit on the left is labeled Sweep DIR/PDM Enable. I'm guessing Sweep DIR = sweep direction (know idea what this does). PDM Enable, I have no idea what this does.

Can someone shed some light on KQO, Sweep DIR/PDM Enable?

By the way, I am truly enjoying all of this.

- - - Updated - - -

[Kevint]

OK, still can't sleep.

The circuit on the left. If 10 is shorted to ground it turns the transistor on, voltage is then passed to the JFET to amplify signal 4. 5 is a square wave input and H I'm guessing is a sawtooth/triangle ramp. Both of those signals go to the multiplier. Not sure of the pinout for A9 or what the output of A9 pin 4 looks like. A multiple of the square wave and H.

Going to sleep now. Maybe.

[ronhip]

Ron, I'm sorry. I forgot to send better photos of the osmium ingot. I have been enjoying your super high quality content, and saw the osmium video posted recently. How did you get such a clean view of the pellet rotating without reflected clutter?

Greg, that Osmium pellet movie was from Theo Gray's great site: https://periodictable.com

No problem about the shot of the pellet. I think that your work is also important and shouldn't be interrupted either! I'm actually 3 elements beyond Osmium, working on Gold right now. For other folks on this forum, check out my Youtube channel for other elements in my series "Tales From The Periodic Table":

https://www.youtube.com/@RonHipschman

And... (I'm required by LAW to say this...) Smash that subscribe button!

Ron