Відео

Thanks for this series, I didn't know that a logic analyzer worked quite as it does, how cool is that? Throwing up machine language and showing exactly to what point the system is getting to just before it falls down. But, I imagine that if the Unraveled book didn't exist finding the fault would have been quite a bit more difficult. In any cas well done :)

This is the best meter which Fluke had made. I had been using it since 40 years and now has given-up on me. LCD issues (went to extent of replacing polarizers), Plastic casing breaking-up (high humidity, I guess). RIP now. Current generation DMMs r power hungry and use-and-throw types.

I have an 8050A that was AC powered from the factory. C38, C39, and C41 are tantalum caps on my unit. C44 seems to have been eliminated; there just isn't a capacitor in the spot next to C41 where the board layout shows C44. So it appears Fluke themselves switched from electrolytic to tantalum (or vice versa) for those caps during the manufacturing run.

Amazing a vintage in-house IC can be replaced, though doubt I could solder surface mount with my condition. Gives one confidence to purchase and repair vintage test equipment. Cheers, Adriel

What does you unit do? Is it not a variable AC power supply? I need a bench top unit which I can set a constant current (4-6 amps), variable voltage (5-25 V) AC output where I'll introduce a load of ~ 1.5 ohms. Is this what I need? What do I need?

I'm glad you produced this series. Just bought an IB-1103 off ebay. Hasn't arrived yet. I've previously read about probable issues, which are hard to fix ore maybe even unfixable. So, your repairs may be of some importance.

Oh this is good 'cept I like the PDP with the purple/orange front cover and all the blinky lights!

Also what'd be really cool, unless you want the big 68k chip, would be to use a 68332. Motorola made a GREAT credit-card sized 68332 board in 1990. Something like that'd be terrific (and a lot faster I believe). Those early 68000 chips were really lethargic.

Nice power supplies in the background! Yeah I really didn't like the PGA mingling with the 68000... what I really want is a two-chip solution like maybe a 68k with a formerly pricey Xilinx FPGA part. I think that'd be really cool.

I need a curve tracer, looking in to the BK

Great terminal! Love that green-yellow CRT color. And it has a modem! I would love to own one of those.

I was an FAE for Motorola processors in Western Canada in the 1980's, and for Motorola VMEbus Unix systems before that... I think I even have a couple of MC68709's in my parts box... The 6801, then 6809, then HC11, were great processors to work with, and you could actually talk to a real application engineer, in Austin, when Intel "application engineers" were sales guys, and a *real* AE was only available if you worked for IBM, or Ford, or... I actually have an application manual for the XC6801, from 1978, on one of those coilly-binders, printed in good old Courier, on a daisy-wheel printer, with hand-drawn diagrams for ports and timers and such... Fun days!

I just happen to have a m68k EVM, 1979 vintage, the very first one in Western Canada...

Ah ha! Since I just happen to have a 6 digit Kelvin Varley divider, I can get a new resistor by matching for my Tektronix dmm, which, somehow, I managed to Woof! the 10 M Input resistor... I do have a 6-1/2 digit HP multimeter, and picked a 10 M from a batch of 1%, that's reading 10.001 M, but now, maybe, I'll try matching a 10 M to the divider chain..

Great video! I'm building a Conrad Hoffman null detector too. I'm would like to use an analog +-100mV millivolt meter so I'm wondering if I've to put a buffer too, and if so does a simple voltage follower works or do I have to drive another way? Thanks

Reset reset reset...

I would think no heat sink compound would cause a failure due to high heat!!

I found two of them in the electronics-dumpster of my company today. Work flawlessly. New cables from the aftermarket and one of them will go on my RV. Tossing out the scrappy 3$ AliExpreas thing.

hey there,, it's too nice, can i get your mail adress?

Once in history the 68k was advanced, I am getting old.

Depending on the manufacturer, you can supply up to 21 vdc , but the internal battery they used was usually no. 6 telephone dry cell

Very nice, I am impressed, I learned to program Fortran on such a Machine about 45 years ago, but I never learned how the components come together.

circles on the active low pins are US style symbols. the triangles are the DIN norm that is in use in europe.

Best of luck. In terms of subscribers, its a very under rated channel.

Awesome, great video! We'll definitely take your feedback on board for the future! Hope you have fun with the kit! 😊

Sorry, but if you are talking about a multimeter, you need to show it larger, but not your head.

It will run on USB power (powerbank or mains adapter), it doesn't need batteries if it is running on BUS power. If that is dying after selecting BUS power then it is faulty, I have had this model, the DR70D and currently use the DR701 which all operate on the same principle. As a side note, I also have the DR40 which operates on the same principle and I have never had any problems with any of them so either your unit has a fault or there is something that you are doing that isn't right. These are all perfectly good, solid and reliable recorders. What you are doing here is unnecessarily overcomplicated, sorry if that offends but I speak from over 7 years experience with all of the recorders I have owned and never experienced any issues.

What was the original price?

Glad you reviewed this. Not long ago (2023), I bought its cousin: a "Tekpower TP8250 Analog Multimeter with NULL Middle Position 0", specifically for the center-zero scales, +- 5 and +-25VDC which are very useful balancing circuit elements. BTW you should always use the mirror scale on analogues to eliminate parallax and maximize accuracy. I have a Triplette VTVM with one of those BIG scales (like the RCA VolOhmyst) and it gets pretty precise.

Thanks for this. I just picked up a 8040A which is an earlier, maybe more portable one. But I will just use it on the bench. One of the battery terminals is broken anyway. I have several 20k+ count DMMs, so this will be a second source of information. I haven't t checked the calibration yet. It will accompany my HP 1740A scope.

I have 8024 b.

Just recently found your videos on the pdp 11 and I love them. I'm planning on building a pdp 11 from parts so this series will be really helpful!

RZ55 is a Micropolis drive, specifically a 1578. Looks like you'll have to try and find another RSTS/E image, or perhaps RT11.

USB-Serial converter only working in one direction... Some of them do not generate proper RS232 voltages like old gear expects. Supplying negative 3V may not be enough. Try a different brand

Will a KW11-K work in there?

There are still modern desktop mainboards with native RS232 ports; my MSI B350 Tomahawk has one.

I have a Fluke 8060A that I still use to this day. So far I have been lucky, no display issues or capacitor leakage issues. I bought it used in the early 90's, it had calibration stickers on it so it may have had the caps replaced at that point.

Nice project. Where did you get the case from?

Wasn't the 11/34 the first one with the interactive console?

i have 1 like that from 1983 , never use it,,,,,,,, is in the box all that time , was a gift , just because i have more than 100 meters i never open the box , i use B&K , RCA SIMPSON VTVM stuff

It's easy to remove that fuse holder wire and usually better and safer if you do.

I have the same HP

So basically it was that 6822 chip after all. What did you do swap it for another chip? I do believe that evil company at the time this version of basic came out was in Albuquerque.

I worked at HP in the 1980s, and I repaired many of this specific model number. The reason HP designed this hybrid was for 2 specific reasons: First, because the voltage divider resistors could be more easily laser trimmed for precision. Secondly, and more importantly, the switching FETs were added onto the same substrate as the resistors for temperature stability. The theory was that any thermal drift would be minimized due to the added mass of the substrate, and in any case, all components on the substrate would drift equally in the same direction, thus effectively canceling the net effect of temperature changes. The idea worked reasonably well, and it is still used today in modern instruments. Your idea of building a replacement board for that hybrid is excellent, but of course the thermal benefits of that hybrid will be lost. In practical terms, I would think it would work fine, considering the level of precision expected from this instrument.

Nice replacement! I dunno if there'll be a final part, if you could include an overview of how that part interacts with the meter to create readings, that would be super awesome.

What calibrator do you use?

You can't get them anywhere...oh wait there's three of them here...LOL! eBay find? Thanks for the refresher on the chip differences. It's bee a good 20 years since I've worked with logic chips.

Thanks for showing it off. I just picked up an 1102 and wanted to see what other faults people are seeing. You sound like "The Dude" from Big Lebowski. ;)

Hi.... Those kits were well designed and built, very good quality...

Now demo ramps on X at 15.75 KHz, and 60Hz on Y - then add Video into the Z axis!