Scope day

Tom,

I've just seen your posts on the Yahoo TeK group. If the SD14's are OK with version 9.xx which heads are supported in 10.xx that aren't in 9.xx? It's really the SD22 and SD24 that I'll be using most - is the SD24 jitter bug present in 9.xx?

John

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ave firmware revision 10 or above, and this unit only has 9.x.

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Yes, it's really for use with SD22 and SD24 heads. I'm shocked at the pric= e of head extender leads though (circa $750!). If it wasn't for the fact t= hat I've used an 11801 in the past and so am familiar with the performance = I'd have been very tempted to go with the HP 54120, since heads for that mo= del effectively have a built in extender lead.=20

John

I honestly haven't tried it. You did get a good deal on that scope. I have the SD14, SD24, and the SD26 and they all seem to work fine. I also have an SD42 for optical pulse work.

One thing for sure is you will want to replace the two battery backed ram chips on the Time Base Controller board (bottom of scope). Here is a source of a known good replacement. You will need to get two of them.

Also, check the data code on the four Li batteries on the cards. Two on the memory board, one on the uP board and one on the I/O board. If they are more than 20 years old, you will be close to the end.

I globbed the end with an epoxy cone and made a not-too-ugly replacement tip. Works fine.

snip

???????

OK, try this one:

Dropbox still doesn't make a lot of sense to me.

That worked. Nice job. What did you use for the pin? The epoxy? I wonder if JB Weld would be ok? Once done, that's the end game.

Thanks, tm

Hi, Tom,

The pins are something we bought to make some little serial flash adapter boards. They are Digikey ED5056-ND, with one end clipped off and filed flat.

The epoxy is "PC-7" epoxy paste from the hardware store. It's pretty ugly stuff, but worked.

Right, you probably only get to do this once.

Have you seen my SD24 pics?

--

John Larkin Highland Technology Inc

Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

Quite a lot of technology packed in that little box. It even looks repairable if you have access to a bonder. Did you make the adapter board for the Flash memory? I found a source for the original 8 pin dips. So far I haven't had any problems.

Someone needs to do the photos of the SD-26 to see how they add the TDR pulse function. It seems to be derived from the calibrate source.

tm

I have an SD26, so maybe I'll open it up if I have time... not the next month or so for sure. I bet it's a depopulated SD24. Actually, I'd prefer to open an SD22, since it's likely to be different. Or one of the faster ones, like the 40 GHz one.

I think that flash adapter is a Bellin, but we do make our own now. The serial flash chips die in these heads, now and then.

This looks interesting.

tm

$39 from Digikey, not cheap !!

Any reason you'd go to eBay? 93C46 parts are current production and something like 20 cents apiece. Do these ahave to be NS?

None whatsoever. It was just the first search I did. Mouser does not have the 93C46N part in stock and shows it eol for Fairchild.

tm

I recall our having trouble getting the DIPs, so we use SO8s and adapters. We made room on one adapter for a code ID label, too.

I'm not surprised they're going EOL, I first used them around 1990. Pretty good run for any chip, let alone a memory chip.

Very snazzy--that's a lot of technical wizardry for ~$100 a pop on eBay!

Cheers

Phil Hobbs

-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics

hobbs at electrooptical dot net