ESI Rv-726 - Page 1
Forum section: electronics / general

author: maginnovision
author_rank: Super Contributor
timestamp: May 13, 2019, 06:48:18 pm
content: I just bought an ESI RV-726 and wanted to see if anyone had any data on it to accompany the thing. It appears to be functionally identical to the fluke 720A so maybe just using that manual outright would suffice but wanted to double check here. I'm also attaching some sales brochure data on the RV-622A, RV-722, and RV-724.

author: Edwin G. Pettis
author_rank: Frequent Contributor
timestamp: May 13, 2019, 11:04:18 pm
content: Back in the day when it was still ESI, you had a fair chance of getting a manual for just about any model ESI had made, even the rarer oddball stuff, but IET only has a very few 'current' models of ESI available and very few original ESI manuals. The KVDs had quite a few variations with different numbers of decades and accuracy, one only had 5 dials, others had up to 8. The RV722 was the closest ESI model to the Fluke 720 unit, unfortunately I can't tell you just how close (or not) the RV726 is to the Fluke unit. There is always the small chance of somebody out there having a manual for these less known units.If these units came out of a good lab the chances are good that the unit is still in tolerance but I have seen instances of drift in certain parts of the circuits, usually in the adjustments, those resistors can be replaced but the ones inside the oil baths, if they go bad, very difficult to fix that, those cans weren't intended to be opened again once sealed.I have the RV-722, not really very close to the Fluke in circuitry.

author: CalMachine
author_rank: Frequent Contributor
timestamp: May 13, 2019, 11:32:24 pm
content: I've got one of these! Unfortunately no documentationThey are a nice alternate to the 720A. Last time I tested mine it seemed to be within spec and had similar performance, given the same source and measuring device, to the 720A that was verified by fluke's standards lab.

author: lowimpedance
author_rank: Super Contributor
timestamp: May 13, 2019, 11:35:54 pm
content: Browsing through the old paper ESI catalogues I have make no mention of this, also Searching the web gives zip, not even 1 picture. (of course my eye sight is not the best these days, so I may have missed it!)Don't suppose you could take a few pictures and post for posterity.Thanks.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: May 14, 2019, 12:19:25 am
content: You have the manual, right?https://www.ietlabs.com/pdf/Manuals/RV-722_im.pdfNear the end of the IET manual--"The following pages are reproduced directly fromesi RV-722 manual" Hopefully this is useful for you...It gives the calibration procedure.

author: Kosmic
author_rank: Super Contributor
timestamp: May 14, 2019, 02:55:42 am
content: My guess is that the RV-726 is the ancestor of the IET KVD-700.https://www.ietlabs.com/kvd-700.htmlYou should try the manual, it's on IET web site.

author: maginnovision
author_rank: Super Contributor
timestamp: May 15, 2019, 02:32:42 am
content: Here are some pictures. Maybe this is the KVD-700 predecessor, I'll have to look into the manual.

author: maginnovision
author_rank: Super Contributor
timestamp: May 15, 2019, 02:34:16 am
content: Some more pictures. I'm currently cleaning the whole thing and the binding posts. One had so much corrosion, only 1, that I had to cut the plastic from the copper threaded piece to clean it enough to get it to budge. Most of them were just gross inside the binding post.

author: maginnovision
author_rank: Super Contributor
timestamp: May 15, 2019, 06:18:12 am
content: One last one all cleaned up. No time to test tonight though.

author: guenthert
author_rank: Frequent Contributor
timestamp: May 15, 2019, 03:56:10 pm
content: Quote from: maginnovision on May 15, 2019, 02:34:16 amWhat are you going to do with the binding post, which lost now its insulator? I'm asking because the plastic of the insulation of the binding post my Datron 1271 (currently in storage, so no immediate need for an answer) became brittle with age to the point that they break off very easily. I don't want to replace the whole set (difficult to acquire and probably quite expensive) or individual binding posts (might need toxic low thermal EMF solder). I'd rather replace the plastic part, but don't know where to get them (if they are sold individually) or how to mount them (are they heated in order to fit?).

author: MiDi
author_rank: Frequent Contributor
timestamp: May 16, 2019, 10:39:28 am
content: I think there are two possibilities to tie the plastic to the binding post:Direct molding of the plastic to the post - I suggest the HP types are.Or press fit it - I suggest e.g. the pomona 3770 series has that.I think both would be hard to fix.Edit: maybe self "mold" with colored epoxy and a form made of good part.Perhaps it is possible to relaese the nut and replace only this part.

author: maginnovision
author_rank: Super Contributor
timestamp: May 16, 2019, 09:22:12 pm
content: For this specifically I will probably not do anything since it's not necessary. If I did want to fix it I would likely buy another old piece of ESI equipment and take a nut from it since these just spin right off/on. For you most likely you'd need to find an appropriate alternative like MiDi said since it's a little tougher(and way more expensive) to do. It won't be original but it'd be better than trying to make something or having cracking binding posts.

author: maginnovision
author_rank: Super Contributor
timestamp: June 02, 2019, 01:42:36 am
content: Quote from: CalMachine on May 13, 2019, 11:32:24 pmWould you be able to take a picture of the bridge balance control connections?

author: CalMachine
author_rank: Frequent Contributor
timestamp: June 03, 2019, 04:29:33 pm
content: Quote from: maginnovision on June 02, 2019, 01:42:36 amI'll see what I can do when I get home from work today!

author: maginnovision
author_rank: Super Contributor
timestamp: June 08, 2019, 07:38:31 am
content: Quote from: CalMachine on June 03, 2019, 04:29:33 pmWere you able to get a picture? I removed the pot from mine since it actually did nothing. It had some evidence of someone having touched it as well so I'm hoping by seeing another unit I can figure out just how it's supposed to be set up.

author: maginnovision
author_rank: Super Contributor
timestamp: August 22, 2019, 07:04:48 pm
content: Just an update and a question. I opened the pot and found some metal in the lubricant likely shorting it all out explaining why it did nothing. I've cleaned it all out but now I need to lube it. Any suggestions as to what I should use? I was thinking mineral oil but not sure if that'd be too thin.

author: Kosmic
author_rank: Super Contributor
timestamp: August 23, 2019, 01:34:58 am
content: Deoxit f5 ?https://caig.com/fader-f-series/