RE: differential probes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Jimmy,

At 02:18 PM 7/25/2003 -0700, you wrote:
>Hi Terry,
>
>I sent the boards to you yesterday, but I forgot to send you the fuses. Do 
>you have any, or do you want me to send them to you.


I got LOTs of fuses here.  No worries ;-))


>The banana jacks I got were "little", I didn't know there is more than one 
>size. I don't think that's the kind you wanted, but I threw them on one of 
>the boards anyway, because they're so easy to take off.

Yeah, there is a "little" banana jack "StAnDaRd" size too...  I got all 
that stuff here too...

>
>Here are some pictures of my board 
><http://www.hot-streamer-dot-com/chunkyboy86/diffprobe.jpg>www.hot-streamer-dot-com/chunkyboy86/diffprobe.jpg 
>www.hot-streamer-dot-com/chunkyboy86/diffprobe2.jpg

Them URLs work out to... ;-))

http://hot-streamer-dot-com\chunkyboy86\diffprobe.jpg.JPG

http://hot-streamer-dot-com\chunkyboy86\diffprobe2.JPG

Cool!!!  Does it work???  :o)))

>
>If the voltage of the batteries powering it aren't equal, there is a DC 
>bias, which makes it tough to read small voltages on my old scope. Why 
>wasn't the VOCM pin grounded? Don't say cost ;-))

Hmmmmm...  That darn fancy TI chip was supposed to fix that...  If 
grounding fixes it, use it ;-))

>
>When I hooked it up to my function generator, there were some spikes at 
>the leading edge of the square wave (200khz). The spike doesn't appear 
>with my other probes, so I think that it is fake.

Yeah...  That is that "nitty gritty" stuff...  We needed "real hardware" to 
work out such details.

No worries, the problems you report were sort of expected...  We're still 
$975 less than TEK's price ;-))  Just have to get the stuff here to work 
out the details were the "devil" is ;-))

Cheers,

         Terry

.............