Diodes made in China vs USA

[tictac]

If it was purely a visual comparison yes that would be a poor analysis....

If you look at my first post with the picture attached you'll notice I have marked the diameter of wire for a real UF4007 and the ones I purchased on Ebay.

I examined several UF4007 data sheets and they all have the same minimum requirement for wire size of 0.70 mm. The Ebay diodes have a diameter of 0.53 mm, well under spec for a UF4007.

There's no way the smaller size diodes at going to have the same thermal characteristics of the larger which includes being able to handle 1 Amp of current.

Visual comparison of the Ebay diodes with the 1/2A rated UF diode was simply a further confirmation for me these were not the real deal. The data sheets already prove that...

TT

[trobbins]

Yeh I know about the lead wire diameter - you double posted on diyaudio (http://www.diyaudio.com/forums/parts/32 ... rence.html) - but readers here won't know.

[sluckey]

I'm going to do the test shown on one of the UF4007 datasheets; if they look look close to the specs I'll use them if not, I won't...

What test is that and what were your results?

[tictac]

sadly my very old Tektronics T912 scope and equally old BK signal generator are not up to the task of doing the test shown on the LRC UF4007 datasheet. They call it a reverse recovery time test.

There was another test online that showed what different types of diodes looked like on a scope with a certain test setup and signal generator but I didn't get to it because of the equipment issue.

TT

[martin manning]

Something like this? http://ampgarage.com/forum/viewtopic.ph ... 281&hilit=

[tictac]

Here's one from the LRC datasheet; theres' a similar one floating around the doesnt use the 25vdc supply but uses a dual channel scope with two x10 probes. I don't have two x10 to do that one...

Your little box is a nice setup..... I don't have a curve tracer thought

TT