Re: HP 3336B series 2902 repair
Hello Ed.
?
I tried every single 3336 and 3325 manual I found on the net without any luck.? The instrument I have in my lab seems to be the latest release of the 3336.? I found a manual for a previous version that like my instrument also uses the HP 1820-1691 CPU, but that one has four ROM while my version of the board has only one ROM.
I will keep looking, thank you for the suggestion.
Claude
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Re: HP 3336B series 2902 repair
Try looking for every possible version of 3325 (A and B I think, but maybe there's a C) and of 3336 (A, B, C, maybe more). The 3336 came in several flavors for various communication standards, so you might luck out and find an older/different version of something. Also check for possibly related family members like 3335A (and maybe others), or anything else around there. First guess and see if any exist, then look for manuals. Good luck.
?
Ed
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Re: Agilent 8753ES P? and up arrow on left side of display ?
Hey Roger?
Got a response on the hidden message: ?Caution: No if found: Check R Input Level. ?But can't get any more info. ?Is this sign of a potential YIG failure?
A while back I had an 8753D with a bad YIG and finding a good YIG reasonable is not easy. ?Do you know if ?a 8753D YIG fits an 8753ES? ?I'm 84 and I know I should be doing this but what the hell I am. Recovered from 3 surgeries and chemo comes next for prostrate.
?I searched ?"Fast Sweep" and found it, thanks again.
Hank
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HP 3336B series 2902 repair
Hello to all members.
I'm trying to repair my 3336B series 2902 generator.?The printed manual that was included with the instruments is for series 1930.? The control board (A6) is HP part number 03325-66516 and it is very different from the one described in the manual.? I'm aware that at first sight this is a board made for the 3325, but it seems to be the original one. There is a dip switch to adapt the board for use on the 3325 or the 3336, see attached picture.?I searched for the schematic of this board and I had absolutely no luck, I event tried to contact Keysight but had no results there either. From the date codes on the chips the production date would be mid or late 1991.
Thank you !
Claude VA2 HDD
?
?
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Re: IPA type for 3.5mm connector cleaning
For those who still use
magnetic tape recording, pure IPA is an excellent cleaner for
tape heads. It is fine on the heads in floppy drives and to
clean the lenses on the scanning heads in CDROM drives too.
? Brenda Gentry, KA2IVY
On 2/17/25 14:53, David Feldman via
groups.io wrote:
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I bought four quarts 99.9% from (US) ebay seller a few years ago (approx the same thing now appears to be about USD 26 shipped); the gallon total will last many lifetimes at my rate of usage. I'm using 2.5mm (and occasionally 1.25mm) "foam swabs" found online; those seem to be used for fiber optic connector cleaning (also using same stuff for flux removal after rework soldering); those usually show some visible "stuff" (on the swab) after cleaning a connector that hadn't been cleaned in modern times. No residue ever seen. The result (after connector cleaning) has been significant improvement in cal/measurement consistency, so highly recommend.
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Re: IPA type for 3.5mm connector cleaning
I bought four quarts 99.9% from (US) ebay seller a few years ago (approx the same thing now appears to be about USD 26 shipped); the gallon total will last many lifetimes at my rate of usage. I'm using 2.5mm (and occasionally 1.25mm) "foam swabs" found online; those seem to be used for fiber optic connector cleaning (also using same stuff for flux removal after rework soldering); those usually show some visible "stuff" (on the swab) after cleaning a connector that hadn't been cleaned in modern times. No residue ever seen. The result (after connector cleaning) has been significant improvement in cal/measurement consistency, so highly recommend.
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Re: Agilent 8753ES P? and up arrow on left side of display ?
Hi Hank, If you search that pdf for "Fast Sweep" you should find it easily
Hi Roger
Thanks for your help.? It doesn't have opt 011, it has the test set.I down loaded the manual you listed but couldn't find: Details here page 44 (1-8).? I'm trying to get more info from the seller but he has no tech savvy and is slow.
Hank
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What is the impedance of these transformers? ?If significantly different than 50 ohms you won’t get good results.?
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On Feb 17, 2025, at 11:20?AM, Maciej Kawalkowski via groups.io <kawalkowski.m@...> wrote:
? thru calibration should be enough in S21 case plus we are talking about pretty low frequencies.
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thru calibration should be enough in S21 case plus we are talking about pretty low frequencies.
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Re: IPA type for 3.5mm connector cleaning
Just use 99%. There's a heck of a lot of over-thinking it in this thread!
99% used to be easily available and cheap, but once that pandemic hit, you couldn't get it for love nor money. Thankfully things have pretty much returned to normal, now though.
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Re: Agilent 8753ES P? and up arrow on left side of display ?
Hi Roger
Thanks for your help. ?It doesn't have opt 011, it has the test set.I down loaded the manual you listed but couldn't find: Details here page 44 (1-8). ?I'm trying to get more info from the seller but he has no tech savvy and is slow.
Hank
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Re: IPA type for 3.5mm connector cleaning
It's one of those things that I read about a very long time ago. I don't remember in what document I saw it. Some sort of chemical engineering thing. But it's the kind of thing that sticks in one's mind (well, at least in my mind), even as one gets older. I've never had occasion to need to try it.
DaveD
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On 2/16/2025 6:35 PM, Steve Hendrix via groups.io wrote: On 2025-02-16 6:09 PM, Dave Daniel via groups.io wrote:
Oh. Like separating sugar from gasoline by adding water, agitating and siphoning off the walter/sugar solution. I hadn't thought of that. Cool. Thanks. I bet there's a story behind that knowledge, maybe one that can only be told with the passing of the years.....
Steve Hendrix
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
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Re: Service manual scan post processing
If you send me a PDF of reasonable size, I can give it a try and send the text file output. It may take a day or three as I'm in the middle of setting up a separate workstation that will handle this (along with other tasks) and moving the tools off my desktop system.
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On 2/17/25 10:36, Peter Brown via groups.io wrote: Hi John,?sounds interesting.
Would you be interested in running a few sample pages through the process?
Peter
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Re: Fan and ball bearings on 8340/8341 Sweep Generators
? It may be overkill but I look at fan pressure/flow curves to select replacements. Newer designs are frequently quieter. Be careful replacing AC fans with DC as they can introduce noise onto the supply you tap.?
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On Feb 17, 2025, at 8:18?AM, Dave_G0WBX via groups.io <g8kbvdave@...> wrote:
?
Re:-
From: Jim
Adney
Date: Mon, 17 Feb 2025 15:18:24 GMT
On Mon, Feb 17, 2025 at 12:18 AM, Calvin Guan wrote:
Is there a way to somehow remove the seal and
re-grease the bearings?
Yes. and that's often your very best solution.
Possibly, but only a stopgap solution.? If the bearings have
been running dry (ish) for any length of time, they will have
worn, so even with fresh lubrication they may still rumble
somewhat, and continue to wear.
For the cost and time involved, if you can find a new(er) fan
that fits, has suitable airflow characteristics and electrical
needs etc, best to go that route I think.
Regards.
Dave 'KBV
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Re: Service manual scan post processing
And I should also clarify, that the output of my workflow is a separate text-only file, not a PDF that includes both image and text. I am sure there's a way to combine the text and images into a new PDF, but that's not needed for my project.
John
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On 2/17/25 11:02, Dave Daniel via groups.io wrote: John,
Just so I understand, "Vision" (only) performs the OCR process step of reproducing a printed document in OCR PDF form? Or did I mis-read your post?
DaveD
KC0WJN
On Mon, Feb 17, 2025 at 10:28 John Ackermann N8UR via groups.io < groups.io> <jra@... <mailto:[email protected]>> wrote:
I'm hesitant to bring this up because I'm only just barely beginning to
understand it and create a workflow, but as an alternative to Adobe,
there is a Google Cloud "Vision" API that does OCR of PDF files.
According to ChatGPT, it does a better job than the various open source
tools would, though I don't know how it compares to Acrobat.
You need a Google cloud or workspace account, and from there you set up
a cloud bucket to hold the raw PDFs, and then create an API Key to the
Vision API.? Then a Python script can call the Google APIs to trigger
conversion of the PDF to a text only document.? Most of the pain is
getting the bucket and API set up with the right permissions and
account
info.
Believe it or not, I used ChatGPT to walk me through the whole process
and even write the Python script!? (Which I'm happy to share.)
Google lets you process 1000 pages per month for free, and it's an
additional $1.50/1000 pages thereafter.? But I found that my Google
Workspace account gave me a $300 credit, so I can do a lot of
conversion
before I have to pay any real money.
Anyway, this may be too far down the rabbit hole, but looks like it
would work well for processing large numbers of documents
automatically;
even at $1.50 per thousand pages, it's pretty inexpensive.
John
----
On 2/17/25 10:13, Peter Brown via groups.io <> wrote:
> Thanks, Alexandre? I will take a look.
> Seems like Acrobat Pro v11 is no longer supported? - any idea
experience
> of their current product?
>
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Re: Service manual scan post processing
Yes, my project is focusing on OCR of existing scanned PDFs that lack it. I'm not doing any new scanning (yet).
The Google tool can read other image formats, not just PDFs, so you could directly OCR a pile of JPGs or TIFFs or whatever. But I'm working through a stack of existing manual scans.
John
----
toggle quoted message
Show quoted text
On 2/17/25 11:02, Dave Daniel via groups.io wrote: John,
Just so I understand, "Vision" (only) performs the OCR process step of reproducing a printed document in OCR PDF form? Or did I mis-read your post?
DaveD
KC0WJN
On Mon, Feb 17, 2025 at 10:28 John Ackermann N8UR via groups.io < groups.io> <jra@... <mailto:[email protected]>> wrote:
I'm hesitant to bring this up because I'm only just barely beginning to
understand it and create a workflow, but as an alternative to Adobe,
there is a Google Cloud "Vision" API that does OCR of PDF files.
According to ChatGPT, it does a better job than the various open source
tools would, though I don't know how it compares to Acrobat.
You need a Google cloud or workspace account, and from there you set up
a cloud bucket to hold the raw PDFs, and then create an API Key to the
Vision API.? Then a Python script can call the Google APIs to trigger
conversion of the PDF to a text only document.? Most of the pain is
getting the bucket and API set up with the right permissions and
account
info.
Believe it or not, I used ChatGPT to walk me through the whole process
and even write the Python script!? (Which I'm happy to share.)
Google lets you process 1000 pages per month for free, and it's an
additional $1.50/1000 pages thereafter.? But I found that my Google
Workspace account gave me a $300 credit, so I can do a lot of
conversion
before I have to pay any real money.
Anyway, this may be too far down the rabbit hole, but looks like it
would work well for processing large numbers of documents
automatically;
even at $1.50 per thousand pages, it's pretty inexpensive.
John
----
On 2/17/25 10:13, Peter Brown via groups.io <> wrote:
> Thanks, Alexandre? I will take a look.
> Seems like Acrobat Pro v11 is no longer supported? - any idea
experience
> of their current product?
>
|
Hardy…tried again the other day to send an email direct, but again no joy. I hope your trip to the states was enjoyable. ? To HPAK Group: Apologies for using the BW. ? Tom Holmes, N8ZM ?
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Hi all,
?
I am sorting through my capacious parts bin and came across hundreds of old IF transformers of the kind you see in the transistor radios of the 60s and 70s (see attached pictures). Anyway, they're all color coded to indicate their intended use. Online sources differed in their interpretation of what the colors meant, so I decided to measure them and find out. I have about a hundred of each color and there are about 7 different colors altogether in my collection.
The simplest approach seemed to be to create a fixture so the transformers could be swapped in and out of a socket and readings taken of each in turn. I freely admit I struggled with this part. It ain't pretty, but it's the best I can manage with my shaky hands and poor eyesight. I've hooked this up to my HP VNA, but then it occurred to me I would also need to create some cal standards for this fixture (does that make sense?) Anyway, if you take a look at the pictures you will see what I've at least *attempted* to do here! I know there are terrible strays and parasitics from this lash-up, but the IFs will be relatively low, so I figure I can get away with it.
My question is: given that I'm going to be performing an S21 forward transmission test sweeping from 300khz through 50Mhz, which type of calibration should I choose from the analyzer's calibration menu? Or can I get away with just a normalization? I've only ever done S11 measurements in the past and calibrated with short, open and load. But this is different.....
Suggestions, please.
?
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Re: Service manual scan post processing
My workflow on a linux system ends up with approx 80kBytes/ page, which can be halved by using djvu format. I'm a skinflint, so it only uses free-as-in-beer software...? I've had compliments about the quality, but judge for yourself.
The workflow is described for a single page. Normally there will be a multiplicity of files/pages with numeric suffixes; simply use the traditional shell script wildcards to process them all at once. 1) scan at 300dpi to produce colour jpg file, e.g. "filename.jpg"
2) normally convert filename.jpg to small tiff files using the scancvt script below "scancvt filename.jpg" . That creates variants of the input? "b-filename.tif" and "g-filename.tif". The g-filename.tif variant is better for grayscale images, but the b-filename.tif is good for black and white images and is much smaller. Select the b-* variant unless g-* is necessary. 3) use the standard command "tiff2pdf filename.tif filename.pdf"
4) concatenate all the pdf files into one using "pdfunite filename*.pdf finalManual.pdf
N.B.Occasionally a jpg image is required, in which case replace (2) and (3) to reduce the size using gimp and its posterising actions to produce
"colour.jpg", then convert that file to a pdf using "convert colour.jpg colour.pdf"
If you want to see manual created like that, see That's a 180 page file, mostly text and schematics with a small number of "photos". Average page size is around 80kbytes (pdf) 40kBytes (djvu). Ed at BAMA postprocessed the pdf to produce the djvu file, which of identical quality but half the size. I believe that is achieved by spotting common bits across each page, e.g. a letter "e".
Alternatively see which contains a higher proportion of photos and colour PCB layouts. Still only 100kBytes/page for the pdf.
The scancvt script is...
#!/bin/bash
#
# Digital Camera + This Software + Printer = A Document Photocopier
#
# Input: ?pictures of B&W Text documents taken with a digital camera using
# ? ? ? ? flash from about 3 feet away with no dark border around the page.
#
# Output1: b-file.tif (a very small B&W TIF file)
# Output2: g-file.jpg (a alternative grayscale file)
#
# If input is purely black and white, ?Output1 should be better
# If input is not purely black and white, Output2 may be better
#
# Corey Satten, corey @ , March 2007
do1 () {
? ?echo starting $1 1>&2
? ?BASE="${1##*/}"; NAME=${BASE%.[jJ][pP][gG]}; TMP1="t-$BASE"; TMP2="x-$BASE"
? ?trap 'rm -f "$TMP1" "$TMP2"; exit' 0 1 2 13 15
? ?CGQ="-colorspace gray -quality"
? ?CGT="-compress group4 -density 480x480"
? ?convert $CGQ 99 "$1" -resize 5120x5120 "$TMP2"
? ?convert $CGQ 99 "$1" -resize 1024x1024 -negate -blur 15,15 -resize 5120x5120 "$TMP1"
? ?composite $CGQ 99 -compose plus "$TMP2" "$TMP1" "$TMP1"
? ?convert $CGQ 60 "$TMP1" -normalize -level 50,85% "g-$BASE"
? ?convert $CGT "$TMP1" -normalize -threshold 85% "b-$NAME.tif"
? ?rm -f "$TMP1" "$TMP2"
}
# This tries to detect multiprocessors and run 2 conversions in parallel
# Move CPUS=1 after the test to effectively disable the test.
CPUS=1
if [ -f /proc/cpuinfo ] ;then
? ? CPUS=`grep ^processor /proc/cpuinfo | wc -l`
? ? if [ "$CPUS" -lt 2 ] ;then CPUS=1; fi
fi
for i in "$@"; do
? ?case $#/$CPUS in
? ? 0/*) exit;; ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? # done
? ? 1/*) do1 "$1"; shift;; ? ? ? ? ? ? ? ? ? ? ? ? ?# only one file to do
? ? */1) do1 "$1"; shift;; ? ? ? ? ? ? ? ? ? ? ? ? ?# only one cpu to use
? ? ? *) do1 "$1" & do1 "$2"; wait; shift; shift;; ?# process 2 files at once
? ?esac
done
exit 0
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Re: Fan and ball bearings on 8340/8341 Sweep Generators
Re:-
From: Jim
Adney
Date: Mon, 17 Feb 2025 15:18:24 GMT
On Mon, Feb 17, 2025 at 12:18 AM, Calvin Guan wrote:
Is there a way to somehow remove the seal and
re-grease the bearings?
Yes. and that's often your very best solution.
Possibly, but only a stopgap solution.? If the bearings have
been running dry (ish) for any length of time, they will have
worn, so even with fresh lubrication they may still rumble
somewhat, and continue to wear.
For the cost and time involved, if you can find a new(er) fan
that fits, has suitable airflow characteristics and electrical
needs etc, best to go that route I think.
Regards.
Dave 'KBV
|
Jinxie