Tektronix 2246A with some problems - Page 1
Forum section: electronics / testgear

author: Delillusions
author_rank: Contributor
timestamp: September 21, 2013, 04:40:37 pm
content: Hi!Sorry for disturbing, but I have a question. I'm looking for an oscilloscope. Earlier I wanted to buy a Tektronix 2230, but the price just "gone through the roof. Now I found a Tektronix 2246A, 100MHz, 4 channel scope. But it has a problem.The Channel 4 pick up quite some noise. Only the CH4, the other Channels are quite clean. They got some noise too, but it is just almost as much as Dave got with the Tektronix 2225 CH1. So Ch1-2-3 are OK. I have to tell, a 2 channel scope is enough for me, so the rest is "just" extra. I've got photos, that the CH1-2-3 are working nicely. There's no burns on the CRT,...etc. So it's in quite nice condition.Here's a small video about the CH4 noise:There's nothing connected to the CH4 at the time, the video was made.My question is this:Should I be worried about the noise on the CH4, that it will damage the CH3, and later the rest of the circuits?Thank you for you're help!

author: sync
author_rank: Frequent Contributor
timestamp: September 21, 2013, 05:10:01 pm
content: Quote from: Delillusions on September 21, 2013, 04:40:37 pmIt's a nice scope. I have one too.QuoteDon't worry. It's very unlikely that it will damage the other channels.Does the noise changes when you short the input or set it to .5V/div?You can get the service manual here:http://elektrotanya.com/tektronix_2246a_sm.pdf/download.htmlBut if you don't have good experience in repairing then leave it as it is. Too much risk to break things.

author: Delillusions
author_rank: Contributor
timestamp: September 21, 2013, 05:16:35 pm
content: Thank you for answering my question Sync!Actually I still didn't bought it, and I don't know the answer to the questions you asked about the CH4. But I'm going to ask the seller about it.Thank you again!

author: sync
author_rank: Frequent Contributor
timestamp: September 21, 2013, 05:59:38 pm
content: Ask the seller to run the self test too.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 21, 2013, 07:50:05 pm
content: Quote from: Delillusions on September 21, 2013, 05:16:35 pm\Where are you located and how much is the seller asking?The 2246A is a cool scope but unless you have the skill, parts, and desire to fix a partially operating scope why go down that path?Depending on your location, the 2246A (and other similar models including the 2247) in decent working condition and sometimes very good cosmetic condition might be available at reasonable prices.http://www.ebay.com/itm/TEK-TEKTRONIX-2246A-100-MHz-OSCILLOSCOPE-S-N-B016005-/310734711702?pt=LH_DefaultDomain_0&hash=item48593b6b96#ht_2622wt_1093http://www.ebay.com/itm/TEKTRONIX-2247A-100MHZ-4CH-COUNTER-TIMER-OSCILLOSCOPE-/151126106852?pt=BI_Oscilloscopes&hash=item232fd162e4#ht_1490wt_1093- these are just a couple currently on eBay; if you are patient more will show up at good/better prices

author: Delillusions
author_rank: Contributor
timestamp: September 21, 2013, 08:23:22 pm
content: I live in Hungary (Central Europe).The price around 190$, and it's in my country, and he's ~220km away from me. So I can take a car.Ordering from the Ebay a scope is a bit difficult, since I ordered multiple things and everything I ordered with "Global Shipping Program" was damaged in the shipping process.Ordering a scope with this program is too risky, while without it the shipping cost for one of the scope you just showed me is more than 600$. Not to mention, that I have to pay VAT and Duty after the price of the scope and the shipping cost too. (Yes, the Duty Office says I have to pay VAT after the shipping costs too)Even a scope with "Global Shipping Program" the shipping and the VAT costs me more than 150$ + the price of the scope.So for now I have to order a scope from Europe, so my choices are limited, since I can't afford a brand new. I'm hunting for a Scope for almost a year, that has at least 2 Channel, and around 60+MHz, and it's in a decent condition.I need a Scope, so I can set up my little shop, I need it way more than a hobbyist level, but still not in a professional level.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 21, 2013, 08:40:51 pm
content: Quote from: Delillusions on September 21, 2013, 08:23:22 pmOk, sorry, I didn't know your location.For all of our challenges in the U.S. buying used stuff isn't one of our biggest problems - between eBay, the US Postal Service, FedEx, and UPS we have a a great market for almost everything used.If you are commmited to buying this scope I guess the good news is that even in Europe I'm sure you can get used Tektronix parts. On the other hand, if you are still in shopping mode maybe could stay on the lookout for a used Rigol. I would think with the 2072 becoming so popular and the the 1000Z series coming soon that there must be some Rigol users in Europe who would like to sell their first generation 1102 (100MHz) or their 1052 (if you could live with 50 MHz) for something pretty close to your $190 budget so they can move to a newer model. But if you have your heart set on a used/analog Tek, I get it - they are cool and worth looking for. Good luck, let us know what you wind up doing.

author: Thor-Arne
author_rank: Unknown
timestamp: September 21, 2013, 08:53:56 pm
content: I have a 2246A to, I'm quite happy with it.For the price you mention I wouldn't mind a second one.However, that "noise" doesn't look like any noise I've ever seen on a scope. (Anyone?)

author: Delillusions
author_rank: Contributor
timestamp: September 21, 2013, 09:18:27 pm
content: Nah, it's OK! There was no way for you to know where I live. You asked, I answered and I gave some reasons why I don't wan't to buy it from Ebay.Actually I don't have too much of a problem with the Ebay, but the Scope is too heavy and delicate for it.I know about the Rigol (I saw Dave's review's and hack), but I'm not sure about the DSOs. I'm fairly young(22), but in a way I'm somewhat old fashioned and I like the older Analog Scopes.As a University student I worked at a company. At that Company and at the University we used Agilent DSOs. How should I say? At the company there was an old Kikusui 100MHz scope (older than me) and it allowed me better readingsexcept if I measured digital signals. At that times a DSO was better. At the University I often used an old Russian Scope. So I'm more interested in an Analog Scope with a Digital Storage, and later a DSO if I got the money for it.But I'm still looking, since I didn't bought the Scope. There's another Scope, that still racing with the 2246A and it's a Tektronix 465. It's in a perfectly working condition, 100MHz, 2Channel, pure analog Scope, and it's a little cheaper than the 2246A.

author: eurofox
author_rank: Unknown
timestamp: September 21, 2013, 09:20:38 pm
content: Quote from: Delillusions on September 21, 2013, 08:23:22 pmI bought a lot of instruments in the past, never got anything broken from US, I bought recently a TDS784D and arrived without problem.I don't want to use this global .....I ask to ship USPS with tracking, it is not expensive and shipping time is quite ok, it was 9 days door to door from USA to my home in 9 days including customs clearance.Look on the German ebay, there is a lot more, they usually mark that they ship only to Germany but never got any problem to ship to Belgium.With respect to shipping cost and VAT it is the same hereEuropean rules.eurofox

author: Electro Fan
author_rank: Super Contributor
timestamp: September 21, 2013, 10:41:33 pm
content: Quote from: Delillusions on September 21, 2013, 09:18:27 pmA 465 in good condition would be a very nice scope.

author: sync
author_rank: Frequent Contributor
timestamp: September 21, 2013, 11:53:23 pm
content: I paid 245€ for my working 2246A on Ebay Germany. It's a normal price here. I saw them go for 300+€. They aren't cheep here.I think 140€ (190$) is ok for the slightly damaged scope. If you want a microprocessor controlled analog scope with good measuring functions go for it. Another advantage is it has no mechanical switches in the signal path. Only relays and silicon. No contact problems with old switches and pots.Downsides are the really loud fan and lot of unobtainium parts if it needs to be repaired.

author: nctnico
author_rank: Super Contributor
timestamp: September 22, 2013, 12:20:13 am
content: This may be an option:http://www.ebay.com/itm/IWATSU-DIGITAL-STORAGESCOPE-DS-8608A-100MHz-GPIB-RS232-C-PORT-/150719002787Its quite similar to the Tektronix 2230. I have bought some equipment from this Ebay seller before and they pack it well.

author: sync
author_rank: Frequent Contributor
timestamp: September 22, 2013, 12:29:13 am
content: Quote from: Thor-Arne on September 21, 2013, 08:53:56 pmMaybe fried input jfet (Q151), damaged preamp IC (U240) or simply a broken resistor, cold joint, etc.

author: viperrepair
author_rank: Newbie
timestamp: January 16, 2015, 03:38:00 am
content: Hi, Well I was going to say you answered your own question when you said you would use a Kikusui in school. They are a really nice scope and the Iwatsu is a tremendous scope. IMO. I bought each for less than sixty dollars+shipping on the bay recently . I purchased a Tektronix 2246 For quite a bit more and it worked for a couple of days and funny things started happening. I don't think you could go wrong with a Japanese Scope.