Just bought a Tek 2246 on the 'Bay. This means the 465 will probably need to be sold, assuming the new one is OK and all.
I would entertain serious offers from the good folks who know me here on the Group (USA only, please) prior to putting it up on eBay.
Probably about 175.00 plus freight.
Yes, this is the same 'scope Mr. Yanik helped me with recently. Replaced a bad bridge rectifier.
Everything works great, bright sharp trace, no burns. Physical condition very good, nothing bent or broken, minor scuffs around the case but not involving the face. I have several versions of the manuals etc on PDF.
Any questions please ask.
Thanks.
Mark Z.
--
"I can't die until the government finds a safe place to bury my liver."
I thought about someone maybe getting all worked up about posting something for sale here, but I figured the guys who know me wouldn't care and anyone else, well, you get the idea...
As far as the 2246 breaking, that's why I'm keeping my B&K 100mHz, as a backup.
Tek is the Harley Davidson of oscilloscopes, after all.
"Mark Zacharias" wrote in news:4e59b1db$0$2867$ snipped-for-privacy@newsreader.readnews.com:
While at TEK,I found a lot of channel amp/switch ICs failing,all TEK-made unobtainium ICs. 2245/46/47 series scopes were NOT easy to troubleshoot. That is why I prefer the 2213/2215/2235 series,hardly any Tek-made ICs,and I think you could kludge up a surface mount board to sub for the one TEK- made IC,if necessary.
Plus,most of the 2246 circuitry is on the main board,and VERY hard to get to. The power supply is buried in the middle of the scope,you have to remove the top board to access it. It's a switcher PS,of course.
But the TDS series scopes are even worse for DIY repairs; no schematics at all.
TEK -really- blew it when they sold off the TEK-IC/hybrid manufacturing unit,and I tried to warn them beforehand. Damn beancounters.....
I'm not sure if the sales engineers ever passed on my comments about selling the IC/hybrid unit.Probably not,TEK managers had a way of chilling dissent,they never wanted to hear opposition to their "bright ideas"; Shitty managers. Now they're owned by Danaher. B-)
Oh,and TEK is moving scope production to China. (or has already)
scope serial numbers may start with a "C" for Chinese made stuff,"T" was for Taiwan-made stuff,and "H" for Heenvereen.
Dream on. I have two 2246A scopes and one 2247A. The 2247A is working an on the shelf:
One 2246A is in my "to be repaired one of these daze" pile:
The "to be repaired" 2246A has a large carbonized hole in the PCB where a power transistor used to live. Repairing the board is problematic. Actually, just extracting the board was a near nightmare, which may help explain why I abandoned the repair.
I obtained a service manual with the scopes, and no, you can't have it. There some CD's and prints of the 2246A manual for sale on eBay for $7 to $15.
My other 2246A is either lost, stolen, loaned, or buried somewhere. Last time I tried it, I had to bang on the case to revive an intermittent in the vertical amps somewhere.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Disappointing on the reliability front. Ah, well. It's only money, and as I say, I'm keeping the B&I 100mHz as my primary backup, and this doesn't count a couple miscellaneous 15 and 20 meg Kenwoods and BE&Kiss I have laying around.
Never used a scope with cursor readout - I'm going to have a learning curve on this one. I suspect it will mostly be used as a plain analog scope though, in 35 years mainly working audio I don't think I've ever "needed" a crt readout.
I did not have any illusions about being able to fix the 2246 when (not if) the time comes. I was probably lucky to get the 465 going.
Disappointing on the reliability front. Ah, well. It's only money, and as I say, I'm keeping the B&K 100mHz as my primary backup, and this doesn't count a couple miscellaneous 15 and 20 meg Kenwoods and B&Ks I have laying around.
Never used a scope with cursor readout - I'm going to have a learning curve on this one. I suspect it will mostly be used as a plain analog scope though, in 35 years mainly working audio I don't think I've ever "needed" a crt readout.
I did not have any illusions about being able to fix the 2246 when (not if) the time comes. I was probably lucky to get the 465 going.
I just happen to have a 1948-49 Tek 511A sitting in the shop. Thing works just fine. Of course, this is a classic example of "They don't make 'em like they used to."
Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:
While at TEK,on 1720/1730 PS boards,I used to Dremel out the carbonized area,fill in the hole with epoxy,and then lay new runs and set eyelets. I used cellophane tape over the hole when putting in the epoxy,less finish grinding to make it flat.
I've done that a few times in the past with mixed results. I have a rather pricy power supply waiting for my attention, with a similar hole. Works ok for low impedance circuitry, but I wouldn't use it for hi-v or high impedance. I also use the Scotch tape trick, but also add some fiberglass matting. I've also found that Bondo works better than epoxy because it doesn't shrink when it hardens.
The scopes that I and several friends have were purchased from a former large corporation, that cound them uneconomical to repair. There was a pile of them, which we purchased for peanuts. They were happy to see them go.
Did you notice the TAS 465 scope in the pile to be fixed?
It lights up, runs, but the beam and alpha are stuck on the left side of the screen. Vertical seems to be working but it's difficult to tell with the beam off the screen. Obviously, a horizontal amp problem. Yet, I've been inside 3 times and have not been able to find an obvious culprit. However, I just found a schematic and manual, so I'll probably try again. It has one big advantage... it's light weight.
One of the T922 scopes on top of the pile works. Which one, I forgot. The other has a blown flyback xformer. I haven't found a substitute yet.
The two on the bottom of the pile are both HP 1740A 100MHz scopes. Both have power supply problems, which are probably bad electrolytics. I'm too lazy to fix them.
There are also at least 4 more assorted scopes around the house, and 3 more in the office, some of which work.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
It's easy, but I hardly ever use the cursor for repair work. If the waveform looks "reasonable", that's usually good enough. If I were back to doing design, I might find it useful. What I find handy on the 2246A/2247A is the ability to store and recall setups. I have a few stored for various things I tend to do repeatedly, which saves me some knob twiddling.
Suggestion: Open the box and blow out the dust and crud. Test equipment tends to live longer when the air path isn't clogged.
I suggest you look into a DSO (digital storage oscilloscope)
or USB scopes. This is one that I borrowed, liked, but haven't bought:
At 2Mhz max, it's good enough for audio except when you want to measure near the noise floor. With only 10 bits, that's problematic.
Nothing wrong with believing in luck. Just don't try to rely on it.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:
My carbonized hole was the HV osc xstr,a TIP31C. I never had any problem with epoxy shrinkage. I used a clear epoxy from Hysol. Now I would use my RAKA boat-building epoxy with fumed silica filler.great stuff.
Missed that. Never worked on one.
could also be a sweep problem;sweep triggered,but sweep gen not ramping. might just be a CRT deflection pin lead fell off. I've seen them get loose,and get shaken off in moving the scope.
I always liked the T922/32/35/442. Not the T912.
WOW,most people only have one or two scopes..... :-)
are you fixing them for friends,or the occasional sale?
The TIP31c is good for 100VDC. That's right on the border where I would worry about any remaining carbonized epoxy causing a conduction path. Good to know it worked.
Silica filler, as in sand? Well, that will give it considerable hardness and strength. However, I don't think that will be necessary to repair a PCB. I was dealing with a rather large hole, about 3/4" in diameter. I wanted to make sure than any applied pressure would not crack the epoxy. So, I added fiberglass matt reinforcing.
They look fairly nice inside and seem easy to work. Unfortunately, there are plenty of proprietary parts.
I checked all the loose connection possibilities. All the scope deflections leads have voltage. I don't think it's a trigger problem because the various text labels that should show up on the screen, are also stuck on the left side. I can see them sorta move when I randomly push buttons, so I know they're functional, just not displaying. I'll figure it out eventually. Project for tonite is yet another blown power supply in an IFR-1500 service monitor. Great monitor, disgusting power supply design.
Yep. Not a bad scope, but the 922 is only good for 15Mhz. In these daze of 100MHz scopes, it's kinda limiting.
I forgot to mention 6ea Tek 5110 scopes with 5A18 vertical plug-ins. They're rack mounted into various ham radio repeaters, hi-fi racks, and at radio sites. I got tired of dragging a scope with me every time I needed to do some repairs. So, I just added one into every rack where I thought it might be useful. Works great, except that all the other techs steal my scope probes.
I have friends and I have customers. The difference is that the customers pay me. Otherwise, they're the same.
Some of the better scopes were intended for me to use. Literally, every scope required some form of repair or rework. I tend to buy broken things, and fix them. (Don't ask me why I have 6 chain saws). I plan to sell them eventually, but have not had the time or incentive to fix any of them[1]. Diving into the shop, I see a Tek 2205, HP
182C, and Tek 213 scope/DVM, all of which are in need of something. I didn't know I had that many scopes. Time to find some friends, err... customers, and get rid of them. Otherwise, I'll just repupose my shop as a museum.
[1] That may happen soon, as the computah repair biz is really slow. What I usually do is take a few days off, and diagnose everything and order parts. About 2 weeks later, when the parts arrive late, I do assembly line repair on everything possible. I've done this several times in the past and it works quite well for me. The problem is finding the uninterrupted time.
Incidentally, I just found a box of Tek repair parts, dating back to the 1970's era. Nuvistors, tubes, semiconductors, etc. There's an inventory list, but the boxes have probably been pillaged. Any interest?
There are 4 similar, but smaller plastic boxes stuffed with parts.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:
the TIP-31C supply rail was 40v unreg;the reason why it burned up is the
+5v rail main filter cap ESR shot up,and the switcher drove it back up to
5v and all the other supplies went way higher;the +40 went to over 60vDC. then the HV-osc xstr over dissipated,and burned up the PCB.
no,it's a white superfine powder used in epoxy mixes,for "filling the weave" after fiberglassing your boat.It makes the epoxy thicker,and hard as a rock. Nothing like sand (and a lot cleaner!). Go to Systemthree.com,and read(free download!) their Epoxy Book,it's VERY informative about using epoxies and fillers. I use wood flour,fumed silica,phenolic microballoons,and chopped plastic fibers for fillers,depending on the application. chopped glass fiber is also available,but I've never used it.
I began using this stuff when I briefly returned to large model rocketry;you need strong body tubes and fin attachments with the higher power rocket motors now available.Fun,but an expensive hobby.
the holes I filled were about 0.5" in diameter or less.
Nice thing is that they don't use -any- TEK-made ICs. but they still have those low-pressure cam switch contacts,I'm surprised any are still working. the plastic degrades and the little gold finger contact falls off the spring part.No replacements available,either,AFAIK.
213 and all 200 series scopes are prone to having the plastic locator pins in the case halves break or pull out under shock,and then the PCBs shift around,and the pins spread open the female connectors,the little leaf springs fall out and short things out.It's still a nice little scope,only
1 MHZ BW,but has the nifty on-screen DMM. TEK field service people used to use(and abuse) them.
I've got a 465 that needs both of the dual FET buffer chips that are in the verticle front end (right after the attenuators). I've heard that the 2n5911 is similiar but I'd have to buy hundreds of them which is way beyond what a used parts scope would cost. Do you have any for sale? bg
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