$49 Hitachi V-1100A for repairs - Page 1
Forum section: electronics / beginners

author: jakeottinger
author_rank: Contributor
timestamp: June 29, 2016, 02:47:56 am
content: Hi guys and gals,I know it's not the best practice to be a newb and buy an oscilloscope that needs repairs but Looking at the photos I assumed the thing had been dropped on it's face and knobs were broken and that's all that was wrong. I powered it up and everything seems to work. I figured it would be a simple fix. However I'm having trouble sourcing the pots and knobs for this thing. Attached is a photo of the unit.Any ideas on where where to get these pots? I'm afraid to take it apart at the moment since my bench is a total mess and I'd enevitably loose parts until I clean up.Thanks for any and all replies!

author: tautech
author_rank: Super Contributor
timestamp: June 29, 2016, 04:07:21 am
content: Bugger, that's a shame it's so beat up.In the service manual the BOM may have clues to the value of the pots, type (lin or log) and the original supplier.http://elektrotanya.com/hitachi_v1100a_v1070a.pdf/download.html11.6 MBWait for "processing" to change to "get manual".

author: jakeottinger
author_rank: Contributor
timestamp: June 29, 2016, 04:20:19 am
content: Thanks for the tip on waiting for Processing. I saw this page before but found no way to download. I guess I just had to wait a bit.

author: jakeottinger
author_rank: Contributor
timestamp: July 08, 2016, 12:47:10 am
content: So one of the destroyed pots is a RV2701 part number 8410393 EWK-ANAS 10k+10k. Where the heck can I find that? google only shows phone number reverse lookup for some reason. It's the level control without wich I'm assuming triggering will not happen. Do you think a stereo pot will work? It looks like a stereo footprint. Any Ideas? Thanks guys/ gals

author: neko efecktz
author_rank: Regular Contributor
timestamp: July 08, 2016, 02:07:08 am
content: Just a suggestion.Possibly find one of the same model online in a "not working condition" and salvage the parts from that.if there is board damage you may also be able to salvage boards from the Not Working unit.In the dropped unit check heavy components on the boards and especially the transformer.Bill.

author: edavid
author_rank: Super Contributor
timestamp: July 08, 2016, 02:13:34 am
content: Quote from: jakeottinger on July 08, 2016, 12:47:10 amIt's a dual concentric pot, not a single shaft pot like a normal stereo pot. (If you used a single shaft pot, you would have the same A and B trigger levels, which might not be so bad.)

author: jakeottinger
author_rank: Contributor
timestamp: July 08, 2016, 05:44:36 am
content: I'm starting to doubt the ability of my go to supplier.

author: jakeottinger
author_rank: Contributor
timestamp: July 08, 2016, 05:49:48 am
content: @edavid do you happen to know if that pot is linear or log? Or at least how to test lin vs. log to find out?

author: jakeottinger
author_rank: Contributor
timestamp: July 08, 2016, 06:01:19 am
content: @neko I already bought a non-working o scope, I understand the suggestion but I'm not about to buy another. I'd rather fix this one. Plus the only other Hitachi 1100A's out there sell for 4X the price I paid for this one. I'd much rather solder parts than steal them from other units that cost much more than I paid. I have thought about buying another donor but just can't bring myself to admit defeat just yet...

author: tautech
author_rank: Super Contributor
timestamp: July 08, 2016, 06:17:27 am
content: How good are you at mechanical repairs?Could the pot shafts be repaired?Some closeups of the removed pot might spur some ideas rather than trying to find something that's hard to obtain.

author: jakeottinger
author_rank: Contributor
timestamp: July 08, 2016, 06:22:53 am
content: https://www.dropbox.com/s/11jl68sas9p76k3/20160707_231934.jpg?dl=0sorry for the bad photography but the outer shell is completely severed.

author: edavid
author_rank: Super Contributor
timestamp: July 08, 2016, 03:19:29 pm
content: Quote from: jakeottinger on July 08, 2016, 05:49:48 amI would think linear, since zero trigger level is in the center... it's very unusual to find a log pot in a scope.