Thanks for the info David. Let me know if you might be interested in the remains of mine to enrich your collection... I think I will keep it for a few days then it will dispose of it ....
Hi Vince,
Factory said it all. Bit of info on repair here:
https://www.samuelritchie.com/repair-hp10525aFor some reason the complete probes have been fetching a fair bit on ebay in rcent years.
I have few HP logic troubleshooting bits including a probe, pulser, currrent tracer, clip and comparator. don't really need any more.
Robert.
Thanks for the links, interesting. There is more electronics inside this thing than I would have believed given its vintage...
OK so looks like there is not much hope to rescue this little guy then... at least I tried, I gave him a chance...
Thanks for the info David. Let me know if you might be interested in the remains of mine to enrich your collection... I think I will keep it for a few days then it will dispose of it ....
Yes I would be very interested in saving this early version of the HP logic probe & adding it to my collection
, seems they redesigned the circuit to use less parts for the 1973 "T" version. The tips are almost certainly the same types, that can be used with the HP or Tek scope probes of similar age.
If it needs a new lamp, I won't ruin it with a crappy blue/white LED.
Thanks Robert for the link that shows what is inside, I would never have guessed it was different otherwise. The logic kits seem to be popular with repairers of older computer & arcade boards, can't understand why they are willing to pay crazy money for them though.
David
Yes ! Little guy just found a new home !
Thanks David !
I will send it shortly.
Yes please no blue LED... when I saw that in this repair PDF I just couldn't believe my eyes, I was appalled... I was hoping someone who can appreciate vintage stuff would be a little different from the blue LED band wagon but looks like no, I was wrong, the dreaded blue LED trend has corrupted even the tiniest of niches
Rather than go for the overpriced manuals on ePay for the 10525A (two of which are $50 each, more than a listing for a probe complete
with the manual at $35
), I've done some research and have found out a patent was issued for this HP logic probe, it contains a description of the circuit and a circuit diagram (differs slightly from the 1969 variant in the
repair im-pair pdf, which has an extra diode & resistor).
The only IC is a quad TTL Nand gate from TI, the later probe appears to have a custom IC, possibly related to adding the dim lamp mode for detecting open circuits, as well as reducing the parts count.
David
Rather than go for the overpriced manuals on ePay for the 10525A (two of which are $50 each, more than a listing for a probe complete with the manual at $35 ), I've done some research and have found out a patent was issued for this HP logic probe, it contains a description of the circuit and a circuit diagram (differs slightly from the 1969 variant in the repair im-pair pdf, which has an extra diode & resistor).
The only IC is a quad TTL Nand gate from TI, the later probe appears to have a custom IC, possibly related to adding the dim lamp mode for detecting open circuits, as well as reducing the parts count.
David
I wonder why he placed the Bulb (43) all the way to the left instead of over TR41? It complicates the diagram for no real reason.
McBryce.
I wonder why he placed the Bulb (43) all the way to the left instead of over TR41? It complicates the diagram for no real reason.
The patent is explicit about having the "visual indicator" right next to the test point / electrode.
Yes that's what I thought too, sounded logical to me.
However what I fail to understand is why they tapped the +5V rail at the other end of the schematic, running a super long wire, even crossing another wire... instead of just tapping it literally right by the bulb ?!
Yes that's what I thought too, sounded logical to me.
However what I fail to understand is why they tapped the +5V rail at the other end of the schematic, running a super long wire, even crossing another wire... instead of just tapping it literally right by the bulb ?!
I guess it is merely visual emphasis that the indicator isn't "at" the output, it is "by" the input.
I wonder why he placed the Bulb (43) all the way to the left instead of over TR41? It complicates the diagram for no real reason.
The patent is explicit about having the "visual indicator" right next to the test point / electrode.
Fully with you, but a schematic is a schematic. It's not meant to contain any physical / positional information. I could understand it, if it was some critical RF part that needed to be distanced from some other component, but this is an indicator bulb.
McBryce.
I wonder why he placed the Bulb (43) all the way to the left instead of over TR41? It complicates the diagram for no real reason.
The patent is explicit about having the "visual indicator" right next to the test point / electrode.
Fully with you, but a schematic is a schematic. It's not meant to contain any physical / positional information. I could understand it, if it was some critical RF part that needed to be distanced from some other component, but this is an indicator bulb.
Oh, we agree, but it is fun to be the Devil's Advocate.
The purpose of any diagram is to communicate anything that is considered important.
Many schematics include more than just connectivity, e.g. the Tek 4x5 scopes where schematics also include PCB boundaries, and a PCB is spread across several schematics. Some schematics include physical info, e.g. notation indicating thermal coupling or being on a heatsink etc.
More importantly, they
ought to show components grouped in familiar "design patterns" that indicate the subcircuit's intention. That allows anything departing from that to be instantly visible, and hopefully to highlight something novel and relevant.
I wonder why he placed the Bulb (43) all the way to the left instead of over TR41? It complicates the diagram for no real reason.
The patent is explicit about having the "visual indicator" right next to the test point / electrode.
Fully with you, but a schematic is a schematic. It's not meant to contain any physical / positional information. I could understand it, if it was some critical RF part that needed to be distanced from some other component, but this is an indicator bulb.
Oh, we agree, but it is fun to be the Devil's Advocate.
The purpose of any diagram is to communicate anything that is considered important.
Many schematics include more than just connectivity, e.g. the Tek 4x5 scopes where schematics also include PCB boundaries, and a PCB is spread across several schematics. Some schematics include physical info, e.g. notation indicating thermal coupling or being on a heatsink etc.
More importantly, they ought to show components grouped in familiar "design patterns" that indicate the subcircuit's intention. That allows anything departing from that to be instantly visible, and hopefully to highlight something novel and relevant.
Which in this case, the lodging/registering of a patent, only the bare essentials to protect IP are ever included.
I wonder why he placed the Bulb (43) all the way to the left instead of over TR41? It complicates the diagram for no real reason.
The patent is explicit about having the "visual indicator" right next to the test point / electrode.
Fully with you, but a schematic is a schematic. It's not meant to contain any physical / positional information. I could understand it, if it was some critical RF part that needed to be distanced from some other component, but this is an indicator bulb.
Oh, we agree, but it is fun to be the Devil's Advocate.
The purpose of any diagram is to communicate anything that is considered important.
Many schematics include more than just connectivity, e.g. the Tek 4x5 scopes where schematics also include PCB boundaries, and a PCB is spread across several schematics. Some schematics include physical info, e.g. notation indicating thermal coupling or being on a heatsink etc.
More importantly, they ought to show components grouped in familiar "design patterns" that indicate the subcircuit's intention. That allows anything departing from that to be instantly visible, and hopefully to highlight something novel and relevant.
Which in this case, the lodging/registering of a patent, only the bare essentials to protect IP are ever included.
The patent summary and claims both indicate having the indicator next to the electrode are part of the IP being protected. It is highly beneficial if the text and diagrams support and enhance each other.