'scope clock advice please

Maybe. :-)

In principle it ought to work, if you get the voltages correct. If you don't, it'll either not work, or damage the CRT or something else.

Among the things you'll need to look at, in matching up the various circuits and components, are;

- The required heater (filament) voltage and current for the CRT you are using.

- The cathode, grid and deflection voltages for the CRT you are using.

- The voltages being created by the clock circuit (microprocessor) and being fed to the X and Y inputs of the scope circuit

Read through the data sheet for the DH3-91 CRT that the circuit was designed to work with

The physical size of the CRT doesn't matter very much (directly) but a larger or different CRT may have different voltage or current requirements.

Looks like a fun project! Make some PCBs and offer them here, I'd probably buy one just for fun. I've got a few 'scopes sitting around that aren't doing anything useful...

As for the Mullard scope, it should work with a larger tube, you just may have to raise the deflection voltage a bit. Find the specs on the two tubes to see what the deflection differences are - if any!

John :-#)#

** No pics or diagram showing up for me.

Am I missing something?

.... Phil

Might pay to check around, comes up OK for me in Oz

Loads fine here(Netherlands). Interesting circiut diagram. Needs a few mods, if you dont want a 12v supply.

Could that be it ?

.... Phil

I doubt it. I am using an adblocker and see the page without problem. I don't know what browser you are using, but try using it with all add-ons disabled ("Safe Mode" when using Firefox, for instance). If that allows you to see the page, you have to go back to normal mode and switch each off add-on in turn until you find the one which is stopping the page from displaying.

Peter Wieck Melrose Park, PA

Odd.. You can try converting the web page to a .pdf right on line. If you can open this:

nd a simple circuit called

Works fine for me in Vancouver, BC...

Nice schematics with valves instead of tubes. Must be some furren idear.

John ;-#)#

Works fine here in NZ and I'm using an adblocker AND an anti-tracking add-on (Privacy Badger, I recommend it highly) in Firefox, works in Chrome too.

Based on all the successful responses, the answer is obviously "YES!"

Hi Phil,

I use this site when I'm not sure where the problem is:

Hope that helps!

John :-#)#

Thanks Dave. I downloaded the datasheet for the Mullard tube and I'll compare it to my CRT when it arrives. Eric

I have seen both links. The top one charges $100.00 plus shipping for the kit minus a CRT. I may go this route. The bottom link is to the kit that is no longer available. But I can download the files for the PC boards and the code for the microcontrollers. I did mention this in my post. Eric

Yeah, I saw that kit. $170.00 and he doesnt't even show a picture of the clock display. It's too bad I didn't think about doing this a few years ago when a board could be had for $34.00! Eric