Got myself another scope.

[Tube_Dude]

Re: Got myself another scope.

As the lights are driven by a CCS, you can add a suitable resistor for the suited voltage drop, with 80mA current, and use any available lamp voltage...

[MDOC]

Re: Got myself another scope.

The story claims industrial espionage but it seems obvious to me that cap manufacturers like CapXon know their caps are poor quality and manufacture them just because of that: OEMs don't want things to last, simple.

Or they just don't know the right formula that lasts more than a few years.

[Th3_uN1Qu3]

Re: Got myself another scope.

A little update. My red LED illumination idea kinda failed because of the narrow angle of the LEDs. The bulbs are actually placed so they light from the side. If i bend the LED so that the lens focuses downwards, it looks nasty, if i leave it like the bulbs were, it's too weak. I've salvaged the LED strip from the backlight of that broken Aspire One LCD, maybe i could use that.

I've also fixed the trace noise issue. It was the power supply caps after all. I had the bright idea to check the rails with the other scope - although i wasn't expecting to see much. However, on the -12v rail, there was around 100mV of ripple. Aha, nailed it. Replaced that cap, and there was still a tiny bit of noise. Checked the 5v rail, nothing appeared on the Panasonic. Checked the 12v rail - it was just a little bit fuzzy, the ripple was too low for it to trigger, but it was there. So i changed the 12v cap as well, and all is well now. The trace is still a little bit fuzzy on the lowest V/div settings, but i believe that is normal. Certainly a lot better than it was.

I've also aligned it a bit - adjusted the power supply voltage and did the attenuator balance today. When switching from 20 to 10mV/div the vertical position of the trace changed slightly. That's the point where the gain of the vertical amp is increased x10, and there's a trimpot for adjusting that balance. Now it doesn't jump at all, it's perfect.

That's miles better than the Panasonic, where the attenuator balance controls are actually on the front panel (screwdriver type adjustments), but they have such a strong temperature dependence, they're only valid at the temperature they were adjusted at. Basically the trace jumps all over the place and there's no way around that.

The trick with increasing the gain of the Y amp x10 is pretty neat - maybe i could apply that to the Panasonic as well, it would make it a bit more useful, as having a minimum sensitivity of 10mV/div (100mV/div with a x10 probe) makes it kinda useless for checking SMPS output ripple.

[ben7]

Re: Got myself another scope.

Sweet dude, that is a beautiful piece of equipment too

[Kiriakos GR]

Re: Got myself another scope.

I bet my Fluke 28II .. LOL that this Scope is an item of the Philips+Fluke era.
My personal function generator is from that era too.

I bet that you can find the schematic of it at easy.

Great catch !! congrats.
http://www.ittsb.eu/my%20bench.html

[MDOC]

Re: Got myself another scope.

I've re-read the old thread about the espionage legend that I seem to remember reading years ago. It's not likely to have happened. More likely, perhaps, the result of greed and compromise.

[twbranch]

Re: Got myself another scope.

not tryin to hijack the thread but the function generator on Kiriakos page is cool. how old is that thing? i gota find one.

[Kiriakos GR]

Re: Got myself another scope.

not tryin to hijack the thread but the function generator on Kiriakos page is cool. how old is that thing? i gota find one.

hijack over hijack
There is a full description at the top of the pictures.