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come out a tad earlier than the similar in function but not identical ExarI have one of these very old trainer breadboards that has several
replaceable modules. The problem I have is the function generator module
"101A Function Generator" does not work. No output signal except for the
dc offset. I have checked the power supply rails and they seem to be
good. I was looking for any documentation or service information.
I bet it uses the Intersil 8038, the vintage is right and that device did
Makes sense I've seen a similar modern design but the problem is that one DIP has a heat sunk glued to it and I can't read the part number. It looks like this is the part though. Chip has positive and negative power but no output signals. I suspect its the chip. If the passive components had drifted there would be some type of signal and all I get it the same noise patterns from all three output pins.On Mon, 8 Apr 2013, nick wrote:
I have one of these very old trainer breadboards that has several
replaceable modules. The problem I have is the function generator module
"101A Function Generator" does not work. No output signal except for the
dc offset. I have checked the power supply rails and they seem to be
good. I was looking for any documentation or service information.
I bet it uses the Intersil 8038, the vintage is right and that device did
come out a tad earlier than the similar in function but not identical Exar
function generator ICs. Open it up and check, if it uses that IC then it
will be easy to find a sample circuit that it likely is following. If the
IC is bad, there were later variants of the IC that are either directly
plug in or similar enough to plug in with some changes.
It wouldn't be in the Bug Books, those were just about the TTL.
Michael
the same number of pins, then press on. See what pins the voltage goesOn Tuesday, April 9, 2013 12:25:09 AM UTC-4, Michael Black wrote:
On Mon, 8 Apr 2013, nick wrote:
I have one of these very old trainer breadboards that has several
replaceable modules. The problem I have is the function generator module
"101A Function Generator" does not work. No output signal except for the
dc offset. I have checked the power supply rails and they seem to be
good. I was looking for any documentation or service information.
I bet it uses the Intersil 8038, the vintage is right and that device did
come out a tad earlier than the similar in function but not identical Exar
function generator ICs. Open it up and check, if it uses that IC then it
will be easy to find a sample circuit that it likely is following. If the
IC is bad, there were later variants of the IC that are either directly
plug in or similar enough to plug in with some changes.
It wouldn't be in the Bug Books, those were just about the TTL.
Michael
Makes sense I've seen a similar modern design but the problem is that
one DIP has a heat sunk glued to it and I can't read the part number. It
looks like this is the part though. Chip has positive and negative power
but no output signals. I suspect its the chip. If the passive components
had drifted there would be some type of signal and all I get it the same
noise patterns from all three output pins.
Find a datasheet for the 8038, and count pins. It the "unknown" IC has
Thanks for the tips. I took the chip out and put it in a breadboard with one of the example circuits. Since there was no signal output with the chip in either circuit I suspect the chip. At this point I'm not going to bother finding a replacement IC.On Tue, 9 Apr 2013, nick wrote:
On Tuesday, April 9, 2013 12:25:09 AM UTC-4, Michael Black wrote:
On Mon, 8 Apr 2013, nick wrote:
I have one of these very old trainer breadboards that has several
replaceable modules. The problem I have is the function generator module
"101A Function Generator" does not work. No output signal except for the
dc offset. I have checked the power supply rails and they seem to be
good. I was looking for any documentation or service information.
I bet it uses the Intersil 8038, the vintage is right and that device did
come out a tad earlier than the similar in function but not identical Exar
function generator ICs. Open it up and check, if it uses that IC then it
will be easy to find a sample circuit that it likely is following. If the
IC is bad, there were later variants of the IC that are either directly
plug in or similar enough to plug in with some changes.
It wouldn't be in the Bug Books, those were just about the TTL.
Michael
Makes sense I've seen a similar modern design but the problem is that
one DIP has a heat sunk glued to it and I can't read the part number. It
looks like this is the part though. Chip has positive and negative power
but no output signals. I suspect its the chip. If the passive components
had drifted there would be some type of signal and all I get it the same
noise patterns from all three output pins.
Find a datasheet for the 8038, and count pins. It the "unknown" IC has
the same number of pins, then press on. See what pins the voltage goes
to, if that's a match, press on further. With the schematic of a sample
circuit in front of you, it's actually easier to then see if the circuit
matches the sample than to trace out the wiring and then compare.
Michael