On Jun 20, 2024, at 15:03, Joe White <skinnershorse@...> wrote:

?These are from the power supply board of a 3325.? Per OSM they are p/n 03325-66901, 03325-66902, 03325-66903 (left to right), described as "XSTR ASSEMBLY".? The manufacturer is listed as HP.? I have not found the part numbers in any cross-reference lists and I have been unable to identify the parts by their markings.? Any help on identifying the parts and/or replacements is greatly appreciated.
--
Joe White
KW4YW

<3325 xstr.JPG>

I really get annoyed when I see things like "MJE371K? selected" in parts lists. HP, Tek and even Heathkit has lots of them with separate numbers. Problem is that they never tell you what it is selected for such as gain, leakage, input capacitance, or maybe frequency response. Worse is that the selected part might actually be a non-selected off the shelf part which might be more expensive or harder to get. Decision might have been made by a parts buyer controlling costs. Really makes repair tricky.? It would be nice to get scans of the microfiche for the selected parts so we can see what they were selected for.
Just my opinion here...
--
T. Gerbic
Central California

The 1854-0800 (NSN 5961-01-147-2387) was replaced by 1854-0456, which is a TIP41A. ZNTE offers its NTE331 as a replacement. Here is their datasheet:

I am slowly compiling a single cross reference of HP parts, This requiress a lot of time to sort out duplicates, and to find whatever data id available on each part. I curently? have 23 groups in HTML to make it easy to search. Their is a main index that akes you to each catagory, although some may end up split into smaller groups. I will star shring them when I get them looking a little better. It is simple HTML which can be zipped? to install a local copy on your computer.

On Thu, Jun 20, 2024 at 4:03?PM Joe White via groups.io <> <skinnershorse@...> wrote:

These are from the power supply board of a 3325.? Per OSM they are p/n
03325-66901, 03325-66902, 03325-66903 (left to right), described as "XSTR
ASSEMBLY".? The manufacturer is listed as HP.? I have not found the part
numbers in any cross-reference lists and I have been unable to identify
the parts by their markings.? Any help on identifying the parts and/or
replacements is greatly appreciated.
--
Joe White
KW4YW

I really get annoyed when I see things like "MJE371K? selected" in
parts lists. HP, Tek and even Heathkit has lots of them with separate
numbers. Problem is that they never tell you what it is selected for
such as gain, leakage, input capacitance, or maybe frequency
response. Worse is that the selected part might actually be a
non-selected off the shelf part which might be more expensive or
harder to get. Decision might have been made by a parts buyer
controlling costs. Really makes repair tricky.? It would be nice to
get scans of the microfiche for the selected parts so we can see what
they were selected for. Just my opinion here... -- T. Gerbic Central
California

On Fri, Jun 21, 2024 at 07:06 AM, Peter Gottlieb wrote:

You'd really hate working in aerospace where every part, COTS or not, is effectively the same way.

And substitutions are *not* allowed - or, at least the approved substitutions are just as old and made of unobtanium as the preferred part. Sigh.

I'm consdering putting it up on Github, where others can help me? by offering generic numbers? they have used. I find some HP parts in the NSN system, but they are being dropped as the government retires models that use them. Many have a list of alternate parts, and limited data in the description.

I have a list of some Heathkit parts that were supplied to vocational electronics students. The parts accumulated at a local school from students that didn't finish the course. It's in HTML? It was on my old Earthlink websiite

On Sat, Jun 22, 2024 at 12:22?AM tgerbic via groups.io <> <tgerbic@...> wrote:

Michael,
Your a real glutton for punishment...
I started out on a mission to make a parts cross reference for Heathkit
parts.? I started out on my own 40 years ago with a little list based off
equipment I owned. I added to it from time to time. A few years ago I
decided to put some real effort into the most comprehensive cross
reference list I could make.? I pulled all parts lists I could find from
any source on the web. I searched dozens of repair forums, club write-ups,
blogs, test equipment forums, ham radio forums, assembly manuals, circuit
descriptions, and keyword searches through several search engines. Got a
pretty good amount of varied info into a spreadsheet. Next was the hardest
part, completing the part substitution work. It is pretty good after a
couple of years work. But...

I seem to have hit an end point where I just cannot go any further. I
think you may hit the same thing.
- Manufacturer part specs that were never scanned and cannot be found on
the net.
- Paper specs and databooks that don't seem to exist anywhere.
- Part numbers that cannot be looked up, or are reused for other parts.
- Incomplete part numbers that defy guessing the prefixes.
- Parts that are just common names or simple descriptions (maybe not so
bad for HP).
- Then there are parts that do substitute but are unobtainable and a
second level substitution cannot be found.

I ran into lots of problems with the Heathkit list.? I should have started
this spreadsheet 30 years ago. It may be easier for some parts of the HP
list and things like the availability of some info on microfiche will
help. Heath ran things pretty fast and loose. I think there will always be
HP part numbers that don't have enough info to easily match. Close enough
may work for a lot of parts. Just having an industry cross, even if not
available will be helpful. Having been through one experience shows me the
value of a comprehensive list and the difficulty of creating one.

It would be good to get others to contribute and spread around the work,
but I found it is very hard to get anyone interested.

I am currently trying to finish up the Data I/O Unisite family device
support list (software revisions, footprints, device notes, adapters,
etc.).? A mind numbing amount of work.? This may be the last time I take
on one of these projects.

Good luck on your adventure. It is going to be a lot of work.

--
T. Gerbic
Central California

www.archive.org <> has scans of thousands of old dtatabooks that you cn dowload as text orPDF. There is also Bitsavers and? a website that scans old databooks and engineering texts.

I'm in my 70s, so I know that I don't have time to cull informationon millions of parts. The fonts used in older books are not handled well? by the scan to text tools that I've used. Paperport for Windows 95 had the fewest errors, but it is on a computer with a damaged power connector on the motherboard. I can't see well enough to do the required repairs. I sit about three innches from a 24" monitor? and use an 18 point font in bold to edit the test conversions. I miss being able to work eight or more hours a day troublesooting and repairing electronics. I started at 13, in the mid '60s when vacuum tubes were still commmon.

On Sat, Jun 22, 2024 at 12:07?PM Peter Gottlieb via groups.io <> <hpnpilot@...> wrote:

I have some older DATA reference books for diodes and transistors which give
basic info for a huge number of parts.? I don't know if they ever had an
electronic version before quitting publication.

I would put a little time into this if it were an open source resource which
could help many people.

Peter


On 6/22/2024 7:33 AM, Michael A. Terrell via groups.io <>
wrote:
> I'm consdering putting it up on Github, where others can help me? by
offering
> generic numbers? they have used. I find some HP parts in the NSN system,
but
> they are being dropped as the government retires models that use them. Many
> have a list of alternate parts, and limited data in the description.
>
> I have a list of some Heathkit parts that were supplied to vocational
> electronics students. The parts accumulated at a local school from students
> that didn't finish the course. It's in HTML? It was on my old Earthlink
websiite
>
> On Sat, Jun 22, 2024 at 12:22?AM tgerbic via groups.io
<> <>
> <tgerbic@...> wrote:
>
>? ? ?Michael,
>? ? ?Your a real glutton for punishment...
>? ? ?I started out on a mission to make a parts cross reference for Heathkit
>? ? ?parts.? I started out on my own 40 years ago with a little list
based off
>? ? ?equipment I owned. I added to it from time to time. A few years ago I
>? ? ?decided to put some real effort into the most comprehensive cross
>? ? ?reference list I could make.? I pulled all parts lists I could find from
>? ? ?any source on the web. I searched dozens of repair forums, club
write-ups,
>? ? ?blogs, test equipment forums, ham radio forums, assembly manuals,
circuit
>? ? ?descriptions, and keyword searches through several search engines. Got a
>? ? ?pretty good amount of varied info into a spreadsheet. Next was the
hardest
>? ? ?part, completing the part substitution work. It is pretty good after a
>? ? ?couple of years work. But...
>
>? ? ?I seem to have hit an end point where I just cannot go any further. I
>? ? ?think you may hit the same thing.
>? ? ?- Manufacturer part specs that were never scanned and cannot be found on
>? ? ?the net.
>? ? ?- Paper specs and databooks that don't seem to exist anywhere.
>? ? ?- Part numbers that cannot be looked up, or are reused for other parts.
>? ? ?- Incomplete part numbers that defy guessing the prefixes.
>? ? ?- Parts that are just common names or simple descriptions (maybe not so
>? ? ?bad for HP).
>? ? ?- Then there are parts that do substitute but are unobtainable and a
>? ? ?second level substitution cannot be found.
>
>? ? ?I ran into lots of problems with the Heathkit list. I should have
started
>? ? ?this spreadsheet 30 years ago. It may be easier for some parts of the HP
>? ? ?list and things like the availability of some info on microfiche will
>? ? ?help. Heath ran things pretty fast and loose. I think there will
always be
>? ? ?HP part numbers that don't have enough info to easily match. Close
enough
>? ? ?may work for a lot of parts. Just having an industry cross, even if not
>? ? ?available will be helpful. Having been through one experience shows
me the
>? ? ?value of a comprehensive list and the difficulty of creating one.
>
>? ? ?It would be good to get others to contribute and spread around the work,
>? ? ?but I found it is very hard to get anyone interested.
>
>? ? ?I am currently trying to finish up the Data I/O Unisite family device
>? ? ?support list (software revisions, footprints, device notes, adapters,
>? ? ?etc.).? A mind numbing amount of work.? This may be the last time I take
>? ? ?on one of these projects.
>
>? ? ?Good luck on your adventure. It is going to be a lot of work.
>
>? ? ?--
>? ? ?T. Gerbic
>? ? ?Central California
>
>