eBay Tektronix 2247A Oscilloscope - how will it end?

[@poormanselectronicsbench2021]

👍To the "shake & rattle" test, and internal inspection before plugging things in. I have found quite a few "vintage" items that had loose parts and/or broken-damaged switches that could have went much worse if I did not take the time to do an inspection beforehand. I don't even want to operate any knobs or switches until I inspect inside, to insure I am not causing more damage until I verify that operating them won't be harmful to anything. You should brew up some sort of "dim bulb" current limiter as well, to minimize the "magic smoke" on items that may be shorted, and always plug a "new to you" unit into it until you can see it's behavior at first.

[@audionautica6843]

Absolutely correct! I have indeed since built a dim bulb tester which hopefully save some magic smoke.

[@SoddingaboutSi]

I have a few on this era Tek scopes and so far no tants have failed. Good old scopes.

[@audionautica6843]

They are indeed! I had a 7000 series mainframe, and I think it thought the tants were fuses.

[@jimyohe100]

The scopes come (new) with a plastic from cover that was removable. Too bad the seller didn't supply that to you. It would have kept any damage from occurring to the from panel. I found one on eBay for a somewhat high price of AU $85.36 plus AU $53.83 postage from the states. Of course there's no real need for it unless you take with you on your travels.

[@ebayscopeman]

On the battery I think that is only for setups. I have a design for a PCB that uses a FRAM for the 2465B but I need to do some more testing before I can release it. The 2247A is a great analog scope. I wish Tek would have made a 400MHz version of this scope that would have been a real killer scope. I like my 2465B but for an analog scope the 2247A is a great scope.

[@audionautica6843]

Wow - your 2465 board sounds very interesting, and hopefully there will be some demand. I was considering a 2465A, because it doesn't have the Dallas battery backed RAM, but rather a seperate battery, hence theoretically possible to hold the memory contents with a power supply while replacing the battery. I would have happily paid the $600 or so it would have cost to get one from the USA here to Australia. I can't believe the amount of test gear available in the USA for virtually nothing - for us Aussies the freight is usually more than the gear, especially with freight prices as they are. Fortunately this unit came up locally so was much more economical, and I am very happy with it.

[@ebayscopeman]

I have one of these and a 2252A as well, Nice scopes. I have some spare parts if you ever need them. W3OHM

[@audionautica6843]

Thanks! I am finding the counter / timer function very helpful. Great to be able to take DC readings at the same time as a waveform. Hopefully I won't need parts, but am most thankful. Have you replaced the battery? Mine seems to be holding, but I understand that on these a battery failure does not cause it to lose its brain in the same way a 2465B, for example, does.

[@LutzSchafer]

Thanks for the video. The tag tants on your older scope how did they fail? Just losing capacity going open or shorting? I also have the old 645 (or so). There are just too many tants to replace them all blindly. The scope kinda works okay but it shows on channel one some high frequency ripple with shorted input even. This ripple seems to come from the HV PSU and I can trigger on it. Haven't checked all the electolytics yet. They are good ones from Sprague. So I guess this could be tedious because the ripple is only on certain higher voltage front end settings and I really like to rule out the tants. ... B intensity is for the second time base B.

[@audionautica6843]

From memory they failed short circuit.

[@lookylook570]

You really need a tripod….

[@audionautica6843]

Haha - this was my first ever video, filmed on my old iPhone 8. I now have several tripods and cameras so hopefully things are a wee bit better.

[@Carlos-l1m8j]

ok