Hi Ernesto, I stand corrected. How can you forget the dynamic timer....having worked on data processing machines of that bygone era. I have followed a very similar path as you, but I jumped from 447

Might have been a timing capacitor they had a lot of, hence the very precise value. Me, I'd give it about 100 volts headroom.  Then again, I tend to overdesign stuff. Harvey

I think it is a typo instead of "EDAC". Just google "345-076-520-201" Ernesto

Sorry that I am late to this thread, I had a really busy day! I don't know, I think some of the folks on here are right, that it may have just been an overstock and they decided to use this value.

What is “EORG”?

Thanks, Walter. Somebody needs to buy the Tektronix 7934. Those are pretty rare and $375 is a good price (at least IMHO). DaveD

The female connector used in the 7000 mainframes seems to be equivalent to: EORG 345-076-520-201 Ernesto

Hi Brad, A while ago I received a private message from Dan G. to make me aware that the can of C401 is floating at a negative supply. I appreciate very much his use of the private message to

Does anybody know around which serial # the 2440 switched from using a backup battery to using NVRAM? I'm looking at purchasing one on eBay that has an FPP diagnostic error - serial #B013530 (I

"Now U301 is listed on the schematic as a "safety part" . Following back from the parts the manufacturer of this little assembly is still in business and you can actually order the part against the

Since we can't have our giant stuff day party here, thanks to the evil covid-19, we have moved it on line, and I am adding new goodies daily. Everybody gets some free stuff with anything they

Ernesto wrote on 5/2/2020 3:35 PM: Hello, Ernesto-- C401A and C401B are listed as 2X20 uF, p/n 290-036. C430 is listed as (2X20 uF), p/n 290-037 C431A and C431B are listed as 2x 20 uF, p/n

Maybe check the emitter resistors. Any variation in current through these will give a difference in vbe between 'disassociated' emitters that don't have the same emitter current. The one

good to know, thank you for clarifying that

can confirm, the slower plugins are good in the faster frames I too am a big fan of the non storage 5400 scopes

Thanks.  What I was remembering is that there's a different keying from the 5400 frame to the 5000 frame.  Didn't know that some were transplantable.  I'll have to get my 5000 and 5400 frames up

OK, you made me look. I downloaded the SG503 manual, and in the schematics I don't see any problem with Q190 - it's just a dual-emitter RF power transistor.. You should be able to replace it with a

Hi, 5000 plugins do fit and work in the 5400. But not the other way around. Of course the bandwidth is limited by the plugin and no readout. I have some 5000 series plugin such as the 5a14 or the

Hi Ernesto, In my 7A13 the usual problem with the relays is of more concern to me. But I'll have a look at C518. BTW I might also have used a 7A13 in a dual input differential way to compare say E1

Nope.  The 5000 series, TM500, and TM5000 series use 0.156 spacing connectors, the 7000 series uses 0.1 inch spacing connectors. Harvey