You guys are awesome! Thanks a million. You saved me a lot of stress. I'll
pick some up tomorrow

Cheers,

Jerry



"Ray King" wrote in message
.. .
Jerry,
I think you are correct. these are schottkys. these 100uf caps can put
quite a negative punch with out limiting the charge current. I would use
no less than the IN5817 no 18 nor 19.
Ray


"John Popelish" wrote in message
. ..
Jerry Lynds wrote:
Hello,


I need some help determining what value of zener diode is in the path
between the LMH1251 RGBout and the input of the LMH6739.

D1, D2, D3 in schematic below...

http://img333.imageshack.us/img333/6...scoder29mx.gif

or

http://www.national.com/ds/LM/LMH1251.pdf page 9 figure 2

I don't think these are zeners, but Schottkys.

The capacitive coupling is followed by 10k resistors to ground, that
would otherwise try to center the signal swing at zero volts. But the
diodes clamp the negative swing to about -.3 volts, by charging the
capacitors positively, so that, as long as the signal cycle occurs much
quicker than the RC time constant, instead of being centered on ground,
it has a maximum negative excursion just below ground. So the diodes are
part of a level shifting scheme. I suspect almost any small signal
Schottky diode would work, as long is it has a voltage rating well above
5 volts.