That crusty piece you pulled out when you pulled the fan is the bushing for the rear of the CRT. It and the clamp that holds the CRT in usually disintegrates over time. A friend and I developed a replacement for the 500 Series Tektronix scopes and he has them for sale on Etsy. I have them in all my scopes that needed them and they solve the problem.
I am trying to remember if the 585 had a tunnel diode in the trigger circuit that was in a clip in holder ?? If so, maybe there is some corrosion on the contact. It has been a few years since I worked on one of these.
Lubricating the fan should be the first thing you do on these old Tek 500 series scopes. The fan motor sleeve bearings aren't brass, they're typically Oilite or similar which I believe is a porous bronze material which allows them to hold oil. The felt pad stores a small quantity of oil that gets sucked into the bearings over time. Most shaded pole motors use them.
@@ZenwizardStudios The Tek 500 Series scopes were some of the most beautiful instruments ever built. I had a nice Tek 551 30 Mhz Dual beam with a bunch of plug-ins incl. 2x 4-Channel for 8 traces. I could use it as a rudimentary logic analyzer and see the whole 8-bit data bus on my Commodore 64 back in the day. Lost it after my brother died and my SIL had the cops remove me from the property so I lost most of my house stuff that was stored there. It had the separate power supply so the cart was pretty much a requirement. It would heat up the room pretty quickly! Thankfully, I didn't lose my Tek 7844 Dual Beam and the pile of plug-ins I have for it. Tek stuff can be addictive. Sucker for 500 series stuff too!
Problematic triggering could be a sign of failure of the tunnel diode in the trigger circuit. The big advantage of the 585A over the 585 is the tunnel diode triggering, which makes the trigger circuit suitable for such a fast scope. The bad thing about tunnel diodes is that they will sometimes change characteristics on you. The 585A uses a 1N3848 or 152-0140-01 10 mA tunnel diode that isn't too hard to find. There may also be Russian substitutes.
OOOHH a good one today, for once I agree a full strip and rebuild is not a good idea though I do not think a wash in a dishwasher and then a day in an oven is called for ;)
I have a cheap oscillating tripod room fan that uses bearings very similar to those faulty ones in your 585. That style of bearing may not be as uncommon as you think! Another avenue for replacing bearings would be a machine shop. Now it maybe prohibitively expensive to hire a professional machine shop to make a couple of fan bearings but there's no need to go pro! There are also amateur/hobbyist machine shops on TH-cam!
I remember the 545; used it in high school and it was 33Mhz. A 100Mhz scope from that era is truly a work of art; 50nsec/division is insane. Is this a dual-beam scope ? Looks like there are 2 timebases, not just the much-simpler delayed-sweep.
Would a stack of modern 12 inch computer fans (stack a few to get enough static pressure to push through the filter) be insufficient? Sure a 12V supply can be put in the chassis somewhere.... While it would certainly not be true to the era, it might even be much quieter :) ... Hint: some computer fans come in both a cw and ccw rotating version, combining these is reputed to help making more static pressure and less turbulence.... might be a little louder though (rack servers often use counterrotating fan pairs - not quiet, but then these things are small, high rpm, and required to create enough static pressure to basically push all the air through screw holes..... Ah dang, forgot the fan is also used as a ballast...
cannot remember what model, but i had a 500 series when i was a kid and it came with a tiny reel of special solder for the ceramic tag strips and remember the wash it with water lunacy -my horror of thinking of trapped water sitting in the layers of the mains transformer and a rusting transformer core the thing weighed a ton and needed a trolley to move it to another bench (i was around 14-15) it had a non linear trace compressed on the left i think and a very weak trigger ,i knew nothing about valves and didnt want to learn so i replaced it with a lovelly 7403n (except i had dents in my fingers constantly from pressing the tiny square pushrod buttons) and sooo much more practical and safe to work on
You've mentioned going lead free and the accompanying nitrogen setup to allow for the higher 3% silver alloy for the ceramic strips. Is it worth it compared to what most people can get without investing too much, standard leaded with 2% silver, ie 62/36/2? I know tek spec'd something like 60% tin, 37% lead, 3% silver, but they also weren't adamant about that percentage. Also. Any opinion on the two high silver leaded alloys on the market - Cardas quad eutectic which doesn't specify it's silver content level but is assumed to be >3%, or WBT 4%?
N2 is NOT necessary but it is a nice to have as it makes the solder behave better. However the price take for N2 soldering is extremely steep compared to the benefits. Building an N2 setup from scratch will cost north of $4,000.00 when it is all said and done so this will be a non starter for most. The good news is that N2 is not needed. However the Silver solder is REALLY NEEDED. The alloy I an currently using with good results is a Kester product num 24-7068-1402 The Alloy is: Sn - 96.5% Ag - 3.0 Copper - 0.5% 3.3% Flux
Talk about boat anchor 😋 Don't injure your back moving that thing around. Btw, it should be possible to remove the original bearings by heating the metal around them and then pressing them out in a wice. Order new bearings based on the size of the old, and mount them in the same way with heat and preasure.
These fans were pre bearing. They were actually an oiled bushing that ended up getting extremely galled up to the point they destroyed themselves. Unfortunately the fan tare down was.... destructive.
Unfortunately, the only plug-ins suitable for the 585 series scopes are the 80 series Other plug-ins used with the 530 and 540 series scopes will not work without a special adapter.
That crusty piece you pulled out when you pulled the fan is the bushing for the rear of the CRT. It and the clamp that holds the CRT in usually disintegrates over time. A friend and I developed a replacement for the 500 Series Tektronix scopes and he has them for sale on Etsy. I have them in all my scopes that needed them and they solve the problem.
This video is intimidating me to pull out my old 545 and 502 tube types... Old friends I have not used in 35 years, but can't bear to dispose of.
Love the gear-driven attenuators! Nothing says old school like parts you could source from a machine shop!
I am trying to remember if the 585 had a tunnel diode in the trigger circuit that was in a clip in holder ?? If so, maybe there is some corrosion on the contact. It has been a few years since I worked on one of these.
Lubricating the fan should be the first thing you do on these old Tek 500 series scopes. The fan motor sleeve bearings aren't brass, they're typically Oilite or similar which I believe is a porous bronze material which allows them to hold oil. The felt pad stores a small quantity of oil that gets sucked into the bearings over time. Most shaded pole motors use them.
The fan was lubed and checked the baring damage was done before the unit came to the bench unfortunately.
@@ZenwizardStudios The Tek 500 Series scopes were some of the most beautiful instruments ever built. I had a nice Tek 551 30 Mhz Dual beam with a bunch of plug-ins incl. 2x 4-Channel for 8 traces. I could use it as a rudimentary logic analyzer and see the whole 8-bit data bus on my Commodore 64 back in the day. Lost it after my brother died and my SIL had the cops remove me from the property so I lost most of my house stuff that was stored there. It had the separate power supply so the cart was pretty much a requirement. It would heat up the room pretty quickly! Thankfully, I didn't lose my Tek 7844 Dual Beam and the pile of plug-ins I have for it. Tek stuff can be addictive. Sucker for 500 series stuff too!
Problematic triggering could be a sign of failure of the tunnel diode in the trigger circuit. The big advantage of the 585A over the 585 is the tunnel diode triggering, which makes the trigger circuit suitable for such a fast scope. The bad thing about tunnel diodes is that they will sometimes change characteristics on you. The 585A uses a 1N3848 or 152-0140-01 10 mA tunnel diode that isn't too hard to find. There may also be Russian substitutes.
Shaft adapters with a flange are plenty on amazon - though centering an impeller on a flange might be a piece of work...
interesting and happy to see these all. older than my age, i think.
OOOHH a good one today, for once I agree a full strip and rebuild is not a good idea though I do not think a wash in a dishwasher and then a day in an oven is called for ;)
I have a cheap oscillating tripod room fan that uses bearings very similar to those faulty ones in your 585. That style of bearing may not be as uncommon as you think! Another avenue for replacing bearings would be a machine shop. Now it maybe prohibitively expensive to hire a professional machine shop to make a couple of fan bearings but there's no need to go pro! There are also amateur/hobbyist machine shops on TH-cam!
I remember the 545; used it in high school and it was 33Mhz. A 100Mhz scope from that era is truly a work of art; 50nsec/division is insane.
Is this a dual-beam scope ? Looks like there are 2 timebases, not just the much-simpler delayed-sweep.
The 555 was the dual beam this one is a signal beam with A and B time bases.
Would a stack of modern 12 inch computer fans (stack a few to get enough static pressure to push through the filter) be insufficient? Sure a 12V supply can be put in the chassis somewhere.... While it would certainly not be true to the era, it might even be much quieter :) ... Hint: some computer fans come in both a cw and ccw rotating version, combining these is reputed to help making more static pressure and less turbulence.... might be a little louder though (rack servers often use counterrotating fan pairs - not quiet, but then these things are small, high rpm, and required to create enough static pressure to basically push all the air through screw holes..... Ah dang, forgot the fan is also used as a ballast...
cannot remember what model, but i had a 500 series when i was a kid and it came with a tiny reel of special solder for the ceramic tag strips and remember the wash it with water lunacy -my horror of thinking of trapped water sitting in the layers of the mains transformer and a rusting transformer core
the thing weighed a ton and needed a trolley to move it to another bench (i was around 14-15)
it had a non linear trace compressed on the left i think and a very weak trigger ,i knew nothing about valves and didnt want to learn so i replaced it with a lovelly 7403n (except i had dents in my fingers constantly from pressing the tiny square pushrod buttons) and sooo much more practical and safe to work on
You've mentioned going lead free and the accompanying nitrogen setup to allow for the higher 3% silver alloy for the ceramic strips. Is it worth it compared to what most people can get without investing too much, standard leaded with 2% silver, ie 62/36/2? I know tek spec'd something like 60% tin, 37% lead, 3% silver, but they also weren't adamant about that percentage. Also. Any opinion on the two high silver leaded alloys on the market - Cardas quad eutectic which doesn't specify it's silver content level but is assumed to be >3%, or WBT 4%?
N2 is NOT necessary but it is a nice to have as it makes the solder behave better. However the price take for N2 soldering is extremely steep compared to the benefits. Building an N2 setup from scratch will cost north of $4,000.00 when it is all said and done so this will be a non starter for most.
The good news is that N2 is not needed. However the Silver solder is REALLY NEEDED. The alloy I an currently using with good results is a Kester product num 24-7068-1402 The Alloy is:
Sn - 96.5%
Ag - 3.0
Copper - 0.5%
3.3% Flux
Talk about boat anchor 😋
Don't injure your back moving that thing around.
Btw, it should be possible to remove the original bearings by heating the metal around them and then pressing them out in a wice.
Order new bearings based on the size of the old, and mount them in the same way with heat and preasure.
These fans were pre bearing. They were actually an oiled bushing that ended up getting extremely galled up to the point they destroyed themselves. Unfortunately the fan tare down was.... destructive.
Unfortunately, the only plug-ins suitable for the 585 series scopes are the 80 series Other plug-ins used with the 530 and 540 series scopes will not work without a special adapter.
Bronze bushings