Tektronix 555 Troubleshooting to unobtainum

A huge thank you again for all that continue to Join us in the lab for repairs and alignments. The channel would not exist with out all of you so thank you again for dropping by.
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In this video we take a look at a Tek 555 Scope that I am trying to get off the ground and in to the lab. Unfortunately this one has some hidden damage on unobtanium parts and will need to be retired. Not all the videos can end is successes and I have told the patrons that I would post even the not successes so here we GO!
** Repair exposes the Tech to mains electric and should only be done by trained personnel. Errors can be fatal. **

[@d.t.4523]

Cool unit. I'll check on what I kave for vintage gear, but I think I only have a tripple 5 or a 565 left. The short power lead was for setting it up on a cart where 2 feet was plenty. If you want a modern cart, look up cheap welder carts. They might be just right. If you get a dead fan motor take it to an appliance shop, some fridge or microwave fan motors will work. If the fan doesn't fit you can find one of them too. Good luck. Thank you, keep working.

[@petepeterson5337]

I had one of these magnificent scopes when I was in my late teens / early twenties, purchased from Rockwell International. Its bandwidth won't impress people today, but as an analog and moderate speed digital guy, it met all my needs and wants handily. TRIGGERING: It triggers as good as the best modern scopes today. The Dual Beam architecture was key to the most beautiful delayed sweep functionality where the top trace could show some complex waveform and the bottom trace would show a zoomed-in view of interest, where the top trace highlighted the portion of the trace that was expanded on the bottom trace - flawlessly and with vacuum tubes! like most of the cars I have owned, I should have kept that scope.

[@hughgilbert390]

I think the CRT is similar to a 5SP2. It would be very unusual for both heaters to be open ( unless loss of vacuum ). They can withstand significant overvoltage for a while. It is not uncommon to run the heaters at 9-10V for a couple hours during manufacture. I would look at the heater pins of the CRT as those connections may fail, and can often be repaired on CRTs that have hollow pins.

[@ruudslaman6966]

i love anything tek. amazing equipment. sad the tube is bad.

[@Davor-hifi]

Interesting way to oil bearing. I never oiled fan bearings but i do repair/restore among other things turntables and i usually try to disassembly entire motor,clean it and then oil it. That way oil doesn't mix with dust that has been collecting there for i don't know how much years. And i am interested in video of that 585. I don't comment much but i love Tek gear so just keep it comming. :)

[@johnscoles660]

A chap that I know has one, only runs it in winter as it heats his small basement lab so fast he can hardly stand it and overworks the AC 🤣

[@jenniferwhitewolf3784]

Check with Vintage Tek museum in Beaverton. They know people that have stashes of parts not on the open market.

[@Joseph-ut4ui]

The filaments are open in the CRT?; there are two separate filaments for upper and lower beams at pins 1 and 14 and 3 and 13; did you check these? They are powered by two separate windings of T750 in the power supply. That would be a very strange failure to have both filaments open. I do have a good 556 CRT, but I don't think they are the same.

[@AmishSpecialForces]

The 556 CRT is quite different and won’t work. However, I do have a couple 556’s and would really like to buy your CRT as a spare.

[@jenniferwhitewolf3784]

Part numbers for variations of the T555 CRT Part No Name Phosphor Graticule 154-0199-00 (154-199) T5550-2 (T555 P2) P2 (standard) external 154-0219-00 (154-219) T5550-1 (T555 P1) P1 external 154-0220-00 (154-220) T5550-7 (T555 P7) P7 external 154-0221-00 (154-221) T5550-11 (T555 P11) P11 external 154-0476-00 T5550-2-1 P2 (standard) internal 154-0476-01 T5550-7-1 P7 internal 154-0476-02 T5550-11-1 P11 internal 154-0476-03 T5550-31-1 P31 internal

[@thatampguy]

You are doing the lords work!

[@ksbs2036]

What oil do you recommend for the oillite bearings? Shame about the CRT. :-(

[@AmishSpecialForces]

I use Amsoil gun oil with a little HBN mixed in.

[@Dutch-linux]

Bob anderson may know where to get a crt !!!

[@hestheMaster]

I remember an early Mr Carlson's Lab video that blew me away to it's size. It was as big as his chest and weight 113 lbs. From what I recall everything worked fine as Tektronix did not skimp on the components used. His fans were noisy. He also had it on a type 202-2 Tektronix oscy cart (with 1 drawer). Too bad about your T555P2 CRT. Anyone out there have a spare?

[@mymessylab]

Oh what a pity. BTW with type 81 plug-in adapter you can plug your W type on 585. In case you want to sell the 555 as is I’m available.

[@hughgilbert390]

After checking Datasheets, the 5SP2, while similar would NOT be interchangable with the T555 due to many physical and electrical differences.

[@kopaka647]

It could've been sitting for so long that you just have crud on the filaments that needs to be burned off. I've seen a tube afficionado bring a UX-245 back from the dead on a tube tester by just clicking the filament voltage switch up and down a bunch of times before settling it back on 2.5V, so maybe you could do something similar with the 555 CRT? I mean, if you're sure it's dead, then what've you got to lose?

[@jeditoto3441]

I have 535 tube.you can have if it helps. But I live in Europe and don’t ‘know if the tube is still good

[@mirkobruhn9841]

Judging by the size, I think I am fine with my 7844 😅

[@Sigmatechnica]

I considered these for the nice sharp trace but they are just too big and heavy and hot runnign

[@jenniferwhitewolf3784]

Check your email! I just ( 12 October ) sent you a link to a 555 CRT for sale, and a second email with documentation on the different variations of the CRT.