"Jerry Maple" wrote in message
...
In article .com,
says...
I set up a 5.0Vpp 1.0ms positive going pulse with
a 50% duty cycle as measured on the scope and then attempted to apply
it to the input of the gate. As soon as I did this though the pulse
disappeared as though the gate's input was loading it down.

--
Dumb question - did you double check your pinouts on the 7486? Trying
to drive an output pin instead of an input with the pulse generator
could load it down. Pins 3, 6, 8, and 11 are the outputs, according to
http://www.abcsemiconductors.com/com...out/7486.phtml
--

Jerry Maple
General Dynamics C4 Systems
Scottsdale, AZ


It's been several years since I used a Datapulse 101 generator, but it
certainly should be able to drive a single TTL input. In fact, IIRC, that
generator has a 50-ohm output, which, even when loaded with a 50-ohm
termination, will drive quite a load. If the generator's output is being
killed by a TTL input, there is certainly something wrong.
1) Make sure that you aren't AC-coupling the generator to the circuit under
test.
2) Make sure the pulse is ground referenced, with a maximum of +5V peak
pulse amplitude
3) Make sure the TTL gate works when you apply jumpers to Vcc and ground.

If all the above are good, then the most likely cause is a faulty generator.
THose things are very hefty instruments, but they do fail, especially if
someone applies a DC voltage to the output.
Cheers!!!!

--
Dave M
MasonDG44 at comcast dot net (Just subsitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!