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MrBungle · 22nd Jun 2016, 10:23 am

From what I can tell there was only one S61.

The manuals listed are all for D61 units with no mention of the S61. The one on servicemanuals.mobi has a picture of a D61 on the front unfortunately. I think this scope is an awkward one.

I took a detailed look at it last night and roughly traced the timebase and triggering circuit and it based on the same design as the D61 with a very different board layout. I have isolated the purpose of the second transformer. It turns out to just supply the two main analogue rails and the other transformer does the HV and deflection voltages but I didn't poke it as I don't have an HV probe set available.

On a positive note, I hooked up my other scope to it and watched the trigger pulses and noticed that it wasn't triggering correctly on certain timebase positions. A quick poke at the contacts with a tweaker and triggering works better but there is a huge amount of noise. That suggests the wafer switch, despite cleaning, is completely knackered. The rings are all clean so this is probably the contacts themselves. I will extract one, a mammoth task looking at it, and see if I can find a replacement or refurbish it.

If that fails, I shall eviscerate the timebase and controls and use it as X-Y display and as an enclosure for my eternally incomplete spectrum analyser.

22nd Jun 2016, 10:23 am	#7
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Telequipment S61 triggering problems From what I can tell there was only one S61. The manuals listed are all for D61 units with no mention of the S61. The one on servicemanuals.mobi has a picture of a D61 on the front unfortunately. I think this scope is an awkward one. I took a detailed look at it last night and roughly traced the timebase and triggering circuit and it based on the same design as the D61 with a very different board layout. I have isolated the purpose of the second transformer. It turns out to just supply the two main analogue rails and the other transformer does the HV and deflection voltages but I didn't poke it as I don't have an HV probe set available. On a positive note, I hooked up my other scope to it and watched the trigger pulses and noticed that it wasn't triggering correctly on certain timebase positions. A quick poke at the contacts with a tweaker and triggering works better but there is a huge amount of noise. That suggests the wafer switch, despite cleaning, is completely knackered. The rings are all clean so this is probably the contacts themselves. I will extract one, a mammoth task looking at it, and see if I can find a replacement or refurbish it. If that fails, I shall eviscerate the timebase and controls and use it as X-Y display and as an enclosure for my eternally incomplete spectrum analyser.