J
Jon Elson
Guest
Hello, all,
I have a couple Tek DAS9200 and TLA520 logic analyzers with 92A96
acq. boards, and not enough lead sets. I'm building a VME probe board,
and trying to duplicate the network that is in the lead sets. What I've got
so far is what they call the "podlet" has an 87 K series resistor with a
250 nF cap across it, and the leadset has a 185 Ohm series resistor on
the signal wires. That resistor/capacitor combination just seems out
of whack. If this network is supposed to work like a 10:1 scope attenuator
probe, the cap seems way too large. I would have expected tens of pF.
Anyway, using what I have measured off these podlet/leadsets, I constructed
about 75 of these networks on the required signals, put it on a board
with the
VME plugs, and it appears to work, much to my amazement. I just plug
3 of the clear TLC ribbon cables right into the probe board, without the
podlets/lead sets.
Does anyone know what these networks are supposed to be, and if my component
values are right? (The resistance is pretty easy, I'm wondering if my RLC
bridge was confused by the resistor and misread the cap value.) The 87
K and
250 nF are potted inside these single-signal TLC ribbons that plug into the
male housing that plugs into the clear TLC ribbon from the analyzer.
The 187 Ohm
is in the color-coded leads, under shrink-wrap.
Thanks,
Jon
I have a couple Tek DAS9200 and TLA520 logic analyzers with 92A96
acq. boards, and not enough lead sets. I'm building a VME probe board,
and trying to duplicate the network that is in the lead sets. What I've got
so far is what they call the "podlet" has an 87 K series resistor with a
250 nF cap across it, and the leadset has a 185 Ohm series resistor on
the signal wires. That resistor/capacitor combination just seems out
of whack. If this network is supposed to work like a 10:1 scope attenuator
probe, the cap seems way too large. I would have expected tens of pF.
Anyway, using what I have measured off these podlet/leadsets, I constructed
about 75 of these networks on the required signals, put it on a board
with the
VME plugs, and it appears to work, much to my amazement. I just plug
3 of the clear TLC ribbon cables right into the probe board, without the
podlets/lead sets.
Does anyone know what these networks are supposed to be, and if my component
values are right? (The resistance is pretty easy, I'm wondering if my RLC
bridge was confused by the resistor and misread the cap value.) The 87
K and
250 nF are potted inside these single-signal TLC ribbons that plug into the
male housing that plugs into the clear TLC ribbon from the analyzer.
The 187 Ohm
is in the color-coded leads, under shrink-wrap.
Thanks,
Jon