Wanted: Tektronix 2221A Knobs - Page 1
Forum section: electronics / general

author: elliott
author_rank: Regular Contributor
timestamp: September 10, 2011, 07:26:31 am
content: I picked up a Tektronix 2221A the other day for a very good price, its main flaw is a couple broken knobs.I need a Volts/div knob, I tried epoxying mine back together, but it didn't hold. If I can't get one, I'll bore it out and glue in a metal sleeve, but a new knob would be preferred. It is just under 3 inches long, hopefully it was fairly common in other models too.I need a VAR knob for the Sec/div, it was totally missing on mine. Not sure what it looks like, but it goes on a 1/8" shaft with a set screw and it can be pulled, so I don't think it was like the ones on the Volts/div knobs, those would be too hard to get a grip on.I need a flexible coupling for the shaft of the Volts/div VAR knob, I assume these are common, it goes on a 1/8" shaft. I tried looking on McMaster-Carr, they have things that will work, but they are meant for heavier duty applications than just a knob and are quite expensive, I don't need it to be able to handle 6000RPM and 20lb*ft of torque. I think I could probably replace it with a piece of rubber hose and glue, if I absolutely had to.I need a couple of the shafts for the VAR knobs, one on the Volts/div and one on Sec/div, but they aren't super important because they are just 1/8" nylon, I can get 2 feet of it and replace them all.

author: Bored@Work
author_rank: Super Contributor
timestamp: September 10, 2011, 07:47:56 am
content: Tryhttp://www.sphere.bc.ca/test/tek-parts/tek-knobs.html(scroll down). However, the first thing I noted is the shaft coupler you are looking for is sold out. Althoght a usable replacement might be found in RC model building shops. You have to be patient and wait if they get more stock. You will notice they take an arm and a leg for the knobs and any other Tek spare parts.Another option is of course eBay. Sometimes people sell their broken oscilloscopes there in parts, including sets of knobs, too.And don't forget to Google the Tek part number. Sphere above it the most known vendor for Tek spare parts, but there are a few other small sites out there offering one or the other Tek part, Often they just list only the part number.You have to be patient for some Tek spare parts and have to be lucky.

author: elliott
author_rank: Regular Contributor
timestamp: September 10, 2011, 08:02:17 am
content: I already saw that site, everything I need is out of stock. Looks like 366-2148-01 is the Volts/div knob I need, and for $20 each, I would have already ordered if they had any.I didn't think about RC stuff for the coupling, I'll check with a few friends that are into RC.I've looked all over eBay, I think I found the Sec/div VAR knob that I need, but I'm not sure, I sent an email asking for some measurements.

author: Bored@Work
author_rank: Super Contributor
timestamp: September 10, 2011, 08:47:38 am
content: Quote from: elliott on September 10, 2011, 08:02:17 amWhy didn't you tell in advance? Would have saved me the time to dig out the URL.

author: elliott
author_rank: Regular Contributor
timestamp: September 10, 2011, 09:00:53 am
content: I figure the average person posting on a forum like this would have already exhausted Google, which is the first thing I do before posting anywhere, so I didn't think it was worth mentioning in a post asking for parts on a buy/sell board. A board like this is kinda the last resort for parts.For future reference:ridgeequipment.com: I think I found a VAR knob and plan on ordering.qservice.tv: They list the Volts/div, but none in stock. They have the couplers, but they are used and I'd prefer NOS if possible.sphere.bc.ca: List everything I need, only have the VAR knob in stock, Ridge is cheaper.mcmaster.com: They have the 1/8" nylon for the shafts.

author: Unknown
author_rank: Unknown
timestamp: September 10, 2011, 12:54:18 pm
content: Quote from: elliott on September 10, 2011, 09:00:53 amJudging from many posts here, many people post on the forum without even spending a few seconds on Google. If you did spend the time to do some research, great, mentioning it wouldn't hurt.Did you try the TekScopes Yahoo! group? Much more people owning old Teks and Tek parts than here.

author: elliott
author_rank: Regular Contributor
timestamp: September 10, 2011, 05:30:22 pm
content: Quote from: alm on September 10, 2011, 12:54:18 pmStill waiting on approval from the moderator.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: September 10, 2011, 07:03:06 pm
content: Send a message to himhttp://myworld.ebay.com.au/qservice_rhodes/?_trksid=p4340.l2559He cooperates with USA too.Good luck.

author: elliott
author_rank: Regular Contributor
timestamp: September 12, 2011, 11:15:29 am
content: Quote from: Kiriakos-GR on September 10, 2011, 07:03:06 pmGot the same response I've got from other stores, what you see online is all they have and they'll let me know if they get any in stock, not holding my breath though.Finally approved on the tekscopes group, hopefully I'll find someone parting one out.I tried drilling out the broken Volts/Div for a sleeve and it split, that is some really brittle plastic. So there is no hope of fixing that one anymore.I really don't want to have to buy another one for parts.

author: Mat
author_rank: Contributor
timestamp: September 24, 2011, 01:27:48 am
content: Hi!Just ordered some old Tektronix parts from this eBay seller :http://stores.ebay.com/fmtxHe has 22xx series parts.He even had parts not listed on eBay, so if you don't find what you're looking for, I suggest asking him.Didn't receive the parts yet, so can't comment on condition of parts sold.Greetings,Mat