Hi,
I was just given this (rather dirty, but what does one say about the given horse?) cutie:



Considered "portable" (if you don't mind 15 kG)
Any comments welcome as usual.

By the way I also have that similar Tek which is I believe from the same era:

Which is indeed portable. But what are those probe power plugs? Different of course from those of my 7704!
I will probably post that too on the g.ioTek parallel universe.
Renaud

开云体育

On Fri, Jul 12, 2024 at 10:44 AM, nigel adams wrote:

I think the power plugs on the Tek scope may be a Lemo type…

Thanks Nigel, yes I suppose so too. I had a look at the Lemo site. There's a tool to find your particular kind of plug. You select the number of pins and plenty of parameters which I did and the thing told me I now only had too look at 68000 models...
That's only for fun because the only active probe I have is a Tek P6202A and I built a little psu for it to avoid using each time? the 7704A as psu. I only wonder which probes were supposed to be used with the 454. Then I'm pretty sure some kind fellow here will tell me that!
Renaud

The first scope I used at work was a 1740A - similar but with a vernier dial rather than the LED display for the timebase delay.?
My boss was a big HP fan and probably inspired my own enthusiasm for their kit.
Some years later I got a secondhand 1725A (replacing a previous 180A) and it served me for many years. Solid equipment (in more ways than one .. fortunately I didn't have to move it much).

I think it will have some exotic HP hybrids for input stages. If those are broken it will be a problem. But worth repairing if you still enjoy using an analog scope.

I agree with Nigel that the Tek connectors look like Lemo. That half-round polarisation is characteristic. However all the ones I've encountered have smaller pins. You might also check Fischer.

- The probe power sockets on the Tek 454 were Sealectro brand.?
- The HP 1740A is from a later era than the Tek 453/454. The contemporary Tek generation was the much lighter 465 family.
- The HP 174X family had discrete (FET) inputs, followed by an HP-specific hybrid.
- The HP 1743A is a very nice family member: The lovely red LED display does not just show *the* delay time ("time base B")
but differential delay (dual delayed sweep!) *and* does not do it the conventional analog way (voltage difference,
like 7B85/7B80 in the Tek 7000 family) but contains a digital counter circuit, resulting in much higher resolution and accuracy,
see HP Journal 1977-12.
All 174x-series 'scopes share many components and subsystems, so are quite repairable.

Raymond

Hello Raymond,
As I said it was just given to me free so I didn't asked about it's state. Then it doesn't work, or possibly I didn't know how to get a trace, I only spent a very short time.
"All 174x-series 'scopes share many components and subsystems, so are quite repairable."
There's still the HP hybrid failed risk maybe? I will investigate when I have more time for that. I got the original paper Ins/service manual in the pocket over the scope. Nice find!
Thanks for the nice report about that little scope Raymond,
Renaud

Good luck with it, Renaud. The ‘scope is worth the effort, especially if you find the differential time / time interval measurement appealing. Let us know how it goes and ask questions!
These ‘scope are known for bad connectors, broken soldering, defective bridge rectifiers, etc. I haven’t encountered a defective hybrid nor HV multiplier in any family member yet. Also, TO-92 transistors are often broken, I suspect because the mechanical tension from inserting them with their preformed leads causes atmospheric leakage after many years. I’ve encountered as much as 8 or so unrelated failures in one scope.?

I have a todo list of things already very full but I begin to realize that indeed, as you said, it is worth the effort.
Of course all your tips are invaluable Raymond.
As I said I got with the scope, in the pouch, the "Operating and service manual" in an as-new condition. This is maybe silly but it's nearly as much pleasure than the scope itself! Aren't we all nuts?
Thanks,
Renaud