Looking for a decent service manual for HP 1740A and maybe parts / mule? - Page 1
Forum section: electronics / general

author: Specmaster
author_rank: Super Contributor
timestamp: July 13, 2017, 11:01:44 pm
content: I have just aquired a lovely 1740A that has a few issues and I need a manual that is readable. I have downloaded one from their web site which has been scanned so many times that it is only just about readable on screen and no hope at once printed. The schematics are split across multiple pages and once printed in an attempt to tape them together, is unreadable, hence the request. If anyone knows where a decent one can be got, or has one for sale / loan please let me.

author: tautech
author_rank: Super Contributor
timestamp: July 13, 2017, 11:16:09 pm
content: One I got years ago was OK but not 100%.I can't remember the source but the filename is 01740-90909.pdf (26 Mb) and Google returns a few hits.

author: edavid
author_rank: Super Contributor
timestamp: July 13, 2017, 11:49:13 pm
content: Artek has a good PDF for $9.50:http://artekmanuals.com/manuals/hp-manuals/

author: amspire
author_rank: Super Contributor
timestamp: July 14, 2017, 12:39:32 am
content: Quote from: Specmaster on July 13, 2017, 11:01:44 pmI might have a better manual. I will look.

author: amspire
author_rank: Super Contributor
timestamp: July 14, 2017, 01:22:17 am
content: I have an HP1740A service manual that is usable but fairly bad. It may be the same one that you have. The file is just over 26MBytes.To print, you have to boost the contrast. It is only a 72pixels/inch scan which is a bummer. I have attached some low and high contrast samples so you can compare.Edit: Looks like I can get a bit better quality by using a different method (I originally used Photoshop to open the PDF page). Go to a page you want in Adobe Reader, Ctl-A to select the image, right click and copy image. Then open an image edit such as paint.net. In paint.net, you can insert clipboard as new image. Then go to Adjustments->Curves and drag the bottom end of the curve to the right until the contrast is right. You can past pages together in the image editor instead of using paper and tape. Works well.

author: amspire
author_rank: Super Contributor
timestamp: July 14, 2017, 04:56:23 am
content: I noticed that some of the circuit diagrams in the HP1740A manual actually consist of multiple images for a page in the pdf. This makes saving the page as an image a little difficult.A good solution seems to be to get YACReader (https://www.downloadcrew.com/article/34182-yacreader). If you open the PDF, you can go to Options (the cog wheel)-Image Adjustment and by setting the Gamma to 0, Brightness to about 6 and contrast to 115, you get decent contrast. Then you can save each page as an image. Not sure you can actually print from YACReader.YACReader is designed for comic book collections, so you have to make a library folder, put the pdf in the library, and open it from the library.Definitely an improvement on using Photoshop to read the PDF.

author: tggzzz
author_rank: Super Contributor
timestamp: July 14, 2017, 09:26:18 am
content: Quote from: Specmaster on July 13, 2017, 11:01:44 pmHP1740a is a sweet scope.The Artek manuals are good, but you may want to print out some of the schematics on A3 paper.The paper manuals are good in that they pages can be folded out horizontally so you can see schematic, layout and waveforms simultaneously (providing you have a very wide bench!). It also means that scans usually have the pages in an order that doesn't make too much sense in a pdf file.

author: Specmaster
author_rank: Super Contributor
timestamp: July 14, 2017, 06:16:29 pm
content: Quote from: tautech on July 13, 2017, 11:16:09 pmThats the very one that is on Keysights web site (as the new owners of Hewlett Packard), they say it is there for reference / support only as the product is obsolete and to make it worse still, someone has been dicking about with the PDF and added blue and red boxes all over the place, badly which helps to make it a last resort only. Try to print it out, especially the schematics and you're doomed, almost blank sheets of paper are produced. To make it worse, its the same file that the other sites also offer.There are of course other sites that offer manuals for a fee, but I'm worried that I'll pay my money and then get a download which will yield the same file again.

author: Specmaster
author_rank: Super Contributor
timestamp: July 14, 2017, 06:24:34 pm
content: Quote from: Specmaster on July 14, 2017, 06:16:29 pmSo, are you saying that the manuals from Artek are printed ones, not a download link? Are they good quality prints and the illustrations nice and sharp?

author: BravoV
author_rank: Super Contributor
timestamp: July 14, 2017, 06:27:32 pm
content: Done few deals with Artek in the past, although not this scope, they told me all documents they're selling are high quality scan works from original printed manuals.

author: tggzzz
author_rank: Super Contributor
timestamp: July 14, 2017, 06:51:49 pm
content: Quote from: Specmaster on July 14, 2017, 06:24:34 pmThey are a download link to their own scans. I have two of their manuals, and they areveryusable. Not as good as printed manuals, for the reasons I alluded to in an earlier message.I have never heard a bad report about their scans.Here's a detail from their scan of a Tek492 manual.

author: nfmax
author_rank: Super Contributor
timestamp: July 14, 2017, 07:14:08 pm
content: I have a paper copy of this manual, so if you get stuck with a poor quality PDF let me know & I'll try and help you out.Which reminds me, I need to get the delayed sweep working again (it doesn't trigger)

author: Specmaster
author_rank: Super Contributor
timestamp: July 14, 2017, 08:13:44 pm
content: Quote from: nfmax on July 14, 2017, 07:14:08 pmThanks for the offer which I may take you up on if the scan is of poor quality, but so far based on the evidence of tggzzz I have ordered a copy from Artek.Like Dave, I'm impressed by the build quality of this scope, although gaining access to some parts is a, or at least looks to be a real nightmare. When I opened it up for the first time, it was like it had just come out of the factory, not a spot of dirt or dust anywhere to be seen and is so nice to see a proper linear power supply, none of this smps rubbish. I have a Hameg HM408-1A which has one of those and its a real pain in the arse as there is so little information available for it and I'm having problems with the smps.If you don't mind, I may ask your advise from time on the HP if you're already familiar with it?One problem I'm having with it so far is that when testing channel B, the vertical position control works just fine, but also the trigger level also seems to do the same vertical function which I don't recall happening until I used switch cleaner on whatever switches and pots I could gain access to easily. Its as if I had pressed the ALT and TRIG VIEW buttons in but with only a single trace on screen???

author: Specmaster
author_rank: Super Contributor
timestamp: July 14, 2017, 08:18:14 pm
content: Quote from: amspire on July 14, 2017, 04:56:23 amI downloaded and tried this program and it does indeed make a big improvement but the downside is that it does not allow you to save the pages or indeed print them which is what I want to do, so I have ordered a copy from Artek and will see if that is any better.

author: tggzzz
author_rank: Super Contributor
timestamp: July 14, 2017, 08:42:10 pm
content: Some personal tips with an HP1740Ahttps://www.eevblog.com/forum/testgear/cheap-tek-500mhz-passive-probes-on-ebay-can-they-be-used-on-any-scope/msg1030288/#msg1030288https://www.eevblog.com/forum/testgear/hp-1741a-oscilloscope-restoration-project/msg980550/#msg980550

author: tautech
author_rank: Super Contributor
timestamp: July 14, 2017, 08:55:01 pm
content: Quote from: Specmaster on July 14, 2017, 06:16:29 pmYep that's the one I've had for years and it WAS good enough to be printed and made into a hard copy manual that I sold with a scope. It was plenty good enough for the repairs I did in the sweep, HV and output stages.I don't now remember if I had to twiddle with printer settings to get a readable copy but rather than dump the whole manual to the printer I would only try the iffy pages and fiddle with them until I could get a reasonable print.I've got a 1740A in need of lots of TLC, maybe we can work through this together............

author: bitseeker
author_rank: Super Contributor
timestamp: July 14, 2017, 10:39:45 pm
content: Quote from: tggzzz on July 14, 2017, 06:51:49 pmThat's the first time I've seen a sample of one of their files. Very good quality, indeed. Thanks, tggzzz.

author: Specmaster
author_rank: Super Contributor
timestamp: July 14, 2017, 10:54:19 pm
content: Quote from: tautech on July 14, 2017, 08:55:01 pmWill do my best to help you where I can, I'm still learning all the time, although scopes are by their very nature complicated items, they seem to call out to me the most, but I like all test equipment....

author: tggzzz
author_rank: Super Contributor
timestamp: July 15, 2017, 12:18:18 am
content: Quote from: Specmaster on July 14, 2017, 10:54:19 pmWait until you move onto spectrum analysers and 6/7/8 digit voltmeters

author: tggzzz
author_rank: Super Contributor
timestamp: July 15, 2017, 12:20:15 am
content: Quote from: bitseeker on July 14, 2017, 10:39:45 pmThe Artek owner contributes to both the Yahoo TekScopes and hp_agilent_equipment groups.

author: alm
author_rank: Super Contributor
timestamp: July 15, 2017, 02:40:28 am
content: Back when I was purchasing a manual from Dave for the first time, he had no problem sending me free samples of the particular manuals I was interested in. And when I (once) complained about the quality of one of his scans, he went back and scanned it again and sent me a much better scan a couple of months later. Same with some manuals that had not had their schematics pages stitched.

author: amspire
author_rank: Super Contributor
timestamp: July 15, 2017, 04:38:36 am
content: I have just converted the HP1740A manual to a high contrast manual. Ended up doing it with ImageMagick+Ghostscript. It is too big to add to the forum, so I will post a link as soon as I have uploaded it along with instructions of how to use the ImageMagick "convert" command.

author: amspire
author_rank: Super Contributor
timestamp: July 15, 2017, 05:00:27 am
content: Here is my first attempt at fixing the contrast problem in the HP 1740A manual PDF file.https://amspire.com/192876453/HP1740A_Service_Manual.pdfThis is the method I used.Install Ghostscript and ImageMagick. They are available for all OSes.Open a cmd/terminal window if the same folder as the HP 1740A manual pdf.Run a command like the following:Code:magick convert -density 300x300 "HP1740A Service Manual.pdf" -threshold 80% -quality 100 -normalize -monochrome out.pdfI am not sure if I should be using monochrome, normalize and threshold in the same step. I haven't used Image Magick before.Normalize adjust the document so that the tones go from black to white. Threshold=80% means that any tone less then 80% of white is made black.If anyone manages a better effort, please post it.Richard.Edit: Just uploading a new version with Threshold=84%. Seems to be close to the best compromise.

author: BravoV
author_rank: Super Contributor
timestamp: July 15, 2017, 09:01:20 am
content: Richard, actually the schematic after stitched is pretty good, attached example below for 1st one.