[Restoration]- 1960's Multimeter! Sentinel ME-26D/U - Page 1
Forum section: electronics / general

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: June 19, 2019, 11:00:47 am
content: - 1960's Multimeter! Sentinel ME-26D/UMr Carlson's LabPublished on Jun 18, 2019Sharing more electronic knowledge! Here is a ton of information about electronic repair, restoration, and alignment. See the Carlson Low Voltage Leakage Tester in a comparison test too. Also.. See the "NEW" Carlson Non Contact Signal Injection Probe in action as well. Lots of info here... Enjoy!Posted 06/19/2019

author: Dr. Frank
author_rank: Super Contributor
timestamp: June 20, 2019, 03:49:11 pm
content: Mr. Carlson delivers very polished videos, which I usually really appreciate, as he has a lot of knowledge about vacuum tube devices.But he also polishes the YT comments, i.e. he blanks / censors unwanted negative comments. This I really dislike.So here is a copy of my three times blanked out comment about his latest repair video, in which he really has very little clue about the subject.'Sorry, that repair / DC range calibration was not done in a qualified manner.E.g., it was not necessary at all to replace that nominal 22M, 10% resistor inside the DC probe, as its drift is exactly compensated by this 1V range trimmer alignment. In fact its value or its drift has practically no influence on either DCV range. This is evident, because the change from 26 to 22 MOhm did not change the alignment of the 1V range at all.Also, the replacement of the other range resistors could have been done in a more clever way, e.g. it is necessary to trim only one resistor to get this upper 68.3M resistor, instead of replacing both. It's missing also the important information, which type of resistors you've used as replacement. So did you use modern 1% thin film resistors, or crappy/unstable carbon resistors out of your junk box?Back then, in the Airforce cal lab, I repaired lots and lots of these hp410Bs, so I really can't appreciate your repair methods.'

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: June 20, 2019, 05:12:16 pm
content: Quote from: Dr. Frank on June 20, 2019, 03:49:11 pmUnfortunately, most but not all Youtube Content Creator are doing this because their is a huge amount of negativity within the comment sections To much negative or childish crap and not enough constructive comments I think Mr Carson talks way to much and should edit down his videos for time. Two hours is way to long for a video because people now and days don't have the attention span

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 20, 2019, 05:29:04 pm
content: +1 What John said.The modern man's disease is the lack of time. When we have some free time in which we would like to be entertained, while simultaneously learning a little bit (a weird activity that us engineers like to do), we seldom have the luxury of watching an hour-long or more video.That is the reason I like Dave video's so much. A little introductory banter and then he dives right in, and limiting the video between 20 to 30 minutes. If the topic is extensive, then he can always do a part 2 video.

author: chris_leyson
author_rank: Super Contributor
timestamp: June 20, 2019, 05:52:57 pm
content: It was an interesting repair video but way too long and I think 25% of it was devoted to advertising his Patrion channel and his capacitor leakage tester. EDIT: It can't be too difficult making the leakage current sense resistors an order or two larger in magnitude to increase the sensitivity.

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: June 20, 2019, 06:26:10 pm
content: Quote from: schmitt trigger on June 20, 2019, 05:29:04 pmDave has a lot of intelligence ,integrity, and opinion I've been watching his videos for years now.

author: seaferring
author_rank: Newbie
timestamp: May 17, 2021, 02:12:27 pm
content: Late to this topic, but I just don't understand the sentiment expressed.1. perhaps your comment was deleted because of your aggressive tone: "so I really can't appreciate your repair methods." is pretty harsh - Mr Carlson spends a huge amount of time producing content and perhaps if you had have posted your correction or disagreement in a more respectful way he might have spent time responding to you.2. Both Mr Carlson's Lab and eevblog are educational channels - they are both attempting to achieve the same goals, perhaps in different ways, but they are not in competition and should not be pitted against each other.3. I, and I'm sure many other people, appreciate long videos that don't pander to the YouTube algorithm's insistence on videos of a certain length. Whether people have short attention spans these days can be argued, but that YouTube and their ridiculous metrics forces this on content creators is very problematic. If a video is too long for you don't watch it. If a video contains content I am interested in, especially repair content, then I prefer length over brevity. This is pretty simple stuff.4. If I think the content creator is talking too much about a given point, I can fast forward through that part.Let's try to respect and appreciate content creators who produce content that is not tailored to the almighty algorithm...

author: W3KW
author_rank: Contributor
timestamp: August 24, 2024, 03:18:47 pm
content: Since the topic heading has the word restoration in it, perhaps someone that sees this can tell me how best to remove the insulator on the AC probe to replace the triax cable and then suggest a suitable solution for recreating one.Does anyone have photos of the connections in the probe? Suggestions for the process?My idea for the insulator is two fold. One, do nothing. This meter is basically the HP-410B and that meter’s AC probe is not insulated. Two, use some sort of foam bicycle handle bar material, but to length and possibly heat shrink tubing on top to dress it.Some things I do to my resto’s:Heat shrink tubing on the handle shaft so it moves more quietly and stays in position.Replace the power supply filter cap with a canned capacitor that fits the existing mount perfectly. $8 from justradios.com and many other sources.Replace the safety capacitors. Which are not safety capacitors.Replace the 22k resistor in the dc probe. Not because it’s necessarily out of tolerance, which it always is, but because I like the shielding on the coax as close to the probe tip as possible. The probe works much nicer that way.Replace the common and ohms test leads with high quality probe leads and put a new alligator clip on the common.Drill and mount feet on the bottom of the case.Clean all the knobs with warm soap and water using a toothbrush.Polish the case using Rejuvinate. A paint polish you can buy from Amazon, etc.Test all the tubes. Replace as necessary. I use the Hickok 539C restored by Bernhard Goetz. Brilliant!Usually, out of tolerance resistors can stay, unless they are WAY off, because the meter was designed so well, the calibration system can compensate for them. Usually.I follow all that up with a thorough alignment which it very well spelled out in the manual. A testament to the engineering in this amazing meter.I think they are just brilliant. I own 7 right now and sell them as I finish them. I don’t make money on them, and usually lose money, but that’s not why I do it anyway. I have a keeper ME-26 and a keeper HP-410B. Owning them makes me feel good and just looking at them lowers my blood pressure. LOL.What’s not to like about owning a perfectly working piece of diagnostic equipment that functions perfectly and looks amazing? Analog? I also own a Simpson 260, a Heathkit IM-18, a few Triplett’s, HP-400L, some Leaders, and maybe a few others. Nothing comes into my shack/shop that doesn’t get a full restoration and calibration. So fun and so much to learn.Yes, I own silicon based meters as well and love them too. My new Keysight 34465A is freaking amazing. I also own Fluke, Siglent, etc., etc.Anyway, does anyone have a solution for the AC probe?WesW3KW