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Help with a TEK 502 scope
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Hi to all,
I am new in this forum, a friend of mine tell me about a group of wise nice people. I am restoring an old tek 502 tube scope. And I need some help: Its HV transformer is death, it has a burned winding and it makes sparks - really nice for a christmas tree but not for a scope, defenetely : ( I have been investigating a little bit and I realise that the CRT transformer of my TEK502 is indeed the same that the tek502A, it has 3 rectifier tubes instead of two. Maybe they change it at the middle of production time. The rest of the scope is in good shape, its CRT is almost new, its power supply caps are like new as well and I change death tubes for NOS ones. So, lets say its like a brand new blind scope. So I would need your help. From my point of view the options are: 1. Buy a working HV transformer. If any of you have one and want to sell it, I am interested. 2. Restore it. It is cover by wax, so it would be difficult not to break the little wires. 3. Manufacturing a new one. I have no idea how many turns it has, wire diameter... I am really interested in learning and, if possible, helping other forum partners. So, where do we start? Waiting for your answers. Thanks a million guys!! PS. I do not know how to post images, if any of you say me how i will upload several pictures of the scope. |
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Welcome!
My first scope was a 502, and I really pushed the bandwidth, using it to look at waveforms on the Commodore PET and CBM computers.? It was actually the reason I joined the group too. Unfortunately, I never did repair mine (I think the problem was the rectifier tubes), because too many other projects came up. -Dave From: "jrodriguezcsb@..." <jrodriguezcsb@...> To: [email protected] Sent: Monday, June 11, 2018 7:12 PM Subject: [TekScopes] Help with a TEK 502 scope Hi to all, I am new in this forum, a friend of mine tell me about a group of wise nice people. I am restoring an old tek 502 tube scope. And I need some help: Its HV transformer is death, it has a burned winding and it makes sparks - really nice for a christmas tree but not for a scope, defenetely : ( I have been investigating a little bit and I realise that the CRT transformer of my TEK502 is indeed the same that the tek502A, it has 3 rectifier tubes instead of two. Maybe they change it at the middle of production time. The rest of the scope is in good shape, its CRT is almost new, its power supply caps are like new as well and I change death tubes for NOS ones. So, lets say its like a brand new blind scope. So I would need your help. From my point of view the options are: ? ? ? ? ? 1. Buy a working HV transformer. If any of you have one and want to sell it, I am interested. ? ? ? ? ? 2. Restore it. It is cover by wax, so it would be difficult not to break the little wires. ? ? ? ? ? 3. Manufacturing a new one. I have no idea how many turns it has, wire diameter... I am really interested in learning and, if possible, helping other forum partners. So, where do we start? Waiting for your answers. Thanks a million guys!! PS. I do not know how to post images, if any of you say me how i will upload several pictures of the scope. |
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Bob Albert
The 502 is so old that if you can find one to buy you will be in good shape.? Nonworking units would probably be cheap, although one must factor in shipping costs.
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Bob On Monday, June 11, 2018, 8:02:37 PM PDT, Dave Seiter <d.seiter@...> wrote:
Welcome! My first scope was a 502, and I really pushed the bandwidth, using it to look at waveforms on the Commodore PET and CBM computers.? It was actually the reason I joined the group too. Unfortunately, I never did repair mine (I think the problem was the rectifier tubes), because too many other projects came up. -Dave ? ? ? From: "jrodriguezcsb@..." <jrodriguezcsb@...> To: [email protected] Sent: Monday, June 11, 2018 7:12 PM Subject: [TekScopes] Help with a TEK 502 scope ? Hi to all, I am new in this forum, a friend of mine tell me about a group of wise nice people. I am restoring an old tek 502 tube scope. And I need some help: Its HV transformer is death, it has a burned winding and it makes sparks - really nice for a christmas tree but not for a scope, defenetely : ( I have been investigating a little bit and I realise that the CRT transformer of my TEK502 is indeed the same that the tek502A, it has 3 rectifier tubes instead of two. Maybe they change it at the middle of production time. The rest of the scope is in good shape, its CRT is almost new, its power supply caps are like new as well and I change death tubes for NOS ones. So, lets say its like a brand new blind scope. So I would need your help. From my point of view the options are: ? ? ? ? ? 1. Buy a working HV transformer. If any of you have one and want to sell it, I am interested. ? ? ? ? ? 2. Restore it. It is cover by wax, so it would be difficult not to break the little wires. ? ? ? ? ? 3. Manufacturing a new one. I have no idea how many turns it has, wire diameter... I am really interested in learning and, if possible, helping other forum partners. So, where do we start? Waiting for your answers. Thanks a million guys!! PS. I do not know how to post images, if any of you say me how i will upload several pictures of the scope. | | Virus-free. www.avast.com | |
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Hi Dave and Bob,
Thank you very much for your answers. Yeah Dave, Ido not know what has exactly tek 502, I do not know if it is the glow of its tubes, its vintage appearance... but is has some kind of magic (like Freddy Mercury, sorry for the joke I could not resist). Always is the p¨°sibility of buying anothger one for parts but, what about rewinding it? Has anyone done that? is it posible? |
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Rewinding (and its issues!) HV transformers has very often been discussed in this group. You might search the forum for old messages. A nasty circumstance is that you have 2 HV secondary windings which preferably should be wound bifilar. I recently rewound a 491 HV transformer which had just one HV winding -- far easier. And even then I had to repeat this until I had the proper technique and materials! I would go for a scratch 502A.
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You can upload photos via the website. Go to the Photos section and click New Album et cetera. Or add photos to an existing album when that is allowed by the owner. If you refer to a photo then please add a link in the message since there is no good search facility in the Photos section. Albert
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Hi Albert,
I have been reading in both the forum and the internet and I found quite interesting info like this page: Unfortunately, I do not have 2 HV windings, in fact I have 3. I have 3 diode tubes in the secondary... In this forum however I have not found a clear procedure, I found several links to a previous Yahoo group but I can not access. I will try to upload photos in that way - thanks for the advice : ) I looked in Ebay and only found a 300USD with another 250USD of shippings, as in the programming fiel, it is out of range... and in bad shape Anyway, any idea about: 1. Anyone who sell one for parts or just the parts 2. Rewinding it Thanks for all this support, you are such a nice guys! |
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I saved detailed notes and photos in topic and photo album titled "453 HV Transformer Rewind". Maybe it will be useful, but you will have to figure out your turns counts unless someone else here knows.
HTH, Dave Wise ________________________________________ From: [email protected] <[email protected]> on behalf of jrodriguezcsb@... <jrodriguezcsb@...> Sent: Tuesday, June 12, 2018 2:18 AM To: [email protected] Subject: Re: [TekScopes] Help with a TEK 502 scope Hi Albert, I have been reading in both the forum and the internet and I found quite interesting info like this page: Unfortunately, I do not have 2 HV windings, in fact I have 3. I have 3 diode tubes in the secondary... In this forum however I have not found a clear procedure, I found several links to a previous Yahoo group but I can not access. I will try to upload photos in that way - thanks for the advice : ) I looked in Ebay and only found a 300USD with another 250USD of shippings, as in the programming fiel, it is out of range... and in bad shape Anyway, any idea about: 1. Anyone who sell one for parts or just the parts 2. Rewinding it Thanks for all this support, you are such a nice guys! |
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On Tue, 12 Jun 2018 at 12:07 Dave Wise <david_wise@...> wrote:
I saved detailed notes and photos in topic and photo album titled "453 HVSee </g/TekScopes/album?id=12876>. |
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Thanks for the URL, Siggi. The last picture in the album is my assistant performing a thermal stress test. :)
DW ________________________________________ From: [email protected] <[email protected]> on behalf of Siggi <siggi@...> Sent: Tuesday, June 12, 2018 9:52 AM To: [email protected] Subject: Re: [TekScopes] Help with a TEK 502 scope On Tue, 12 Jun 2018 at 12:07 Dave Wise <david_wise@...> wrote: I saved detailed notes and photos in topic and photo album titled "453 HVSee </g/TekScopes/album?id=12876>. |
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