Recent Posts

1

General Technical Chat / Re: Does anyone make good SSDs any more?

« Last post by coppice on Today at 12:39:27 am »

I'm really getting tempted by the WD RED SA500 drive now. Looks like similar performnce to typical SSDs, but more enterprise grade, and to my understanding the design has barely changed, and no firmware updates released, since it was first available.

Can anyone give me a good reason not to select a WD RED SA500? (speed reasons are only "good" in my books if the speed of this would be actively worse than the spinning rust Toshiba MQ01ABD100 models I am used to)

I know the red is made for NAS usage, but that mainly just means its a bit tougher in its reliability ratings than a normal consumer SSD? And everything I'm reading online so far says WD Red drives can work fine as the sole drive, the boot drive, in a PC.

Thanks

Any SSD made in the last few years can keep a SATA bus saturated almost all the time. Its only the NVMe drives which show speed differences these days.

2

General Technical Chat / Re: What is this 8-knobbed IBM human interface device in a 1980's Boeing photo?

« Last post by coppice on Today at 12:35:09 am »

Wacom used to make these back in the day too. We had stylus/pen for it, the digitizer with the crosshair and also a regular mouse which didn't have a ball but an inductive sensor (optical mice weren't invented/common yet).

Wacom came late in the day, and was always focussed on its pen input, with mice and other gadgets being a secondary focus. They never really offered the high resolution of a Summagraphics, but they lead offer wireless handheld devices. That was their big innovation.

How do you figure? The Wacom tablet I bought in the mid-90s had the same 2540lpi resolution of the SummaGraphics, and as far as I know that was in no way new in that generation of Wacom tablets. The manual specifies 0.15mm accuracy with the puck, 0.25mm with the pen.

It might have been just the lack of a puck with fine crosshairs and a lens for the Wacom tablets, but I found them less effective for digitizing. Now you mention it, the actual steps per centimetre must have been competitive, so achieve their smooth fine pen drawing performance.

Can you be more specific? Are you saying that Wacom’s lens and crosshairs were less effective in some way than SummaGraphics’? Or that they didn’t offer a puck with lens and crosshairs at all? (Because they most certainly did.)

A Summagraphics tablet had a magnifying lens with a a hair line cross on it. I had a Wacom puck with a clear piece of plastic with a fairly thick black cross on it. I never saw an option like the Summagraphics one. Wacom never made anything big enough to be a serious digitizing tablet, anyway.

3

General Technical Chat / Re: Does anyone make good SSDs any more?

« Last post by Infraviolet on Today at 12:34:27 am »

I'm really getting tempted by the WD RED SA500 drive now. Looks like similar performnce to typical SSDs, but more enterprise grade, and to my understanding the design has barely changed, and no firmware updates released, since it was first available.

Can anyone give me a good reason not to select a WD RED SA500? (speed reasons are only "good" in my books if the speed of this would be actively worse than the spinning rust Toshiba MQ01ABD100 models I am used to)

I know the red is made for NAS usage, but that mainly just means its a bit tougher in its reliability ratings than a normal consumer SSD? And everything I'm reading online so far says WD Red drives can work fine as the sole drive, the boot drive, in a PC.

Thanks

4

Repair / Help Identifying SMD Diodes on a Yaskawa SGD7S Stepper Driver PCB

« Last post by Zer00 on Today at 12:28:28 am »

 Hello, I am currently attempting to repair a Yaskawa SGD7S-5R5A00A002 stepper driver that ended up receiving 100 extra AC Volts on the input (ouch). Besides a couple of MOVs being blown, some passive components on the board were also a goner. I also tested some diodes and they were suspicious at best, so I'd prefer to replace them.

The issue is, I have completely failed to identify most of them. Any help in this department would be greatly appreciated. The diode markings are as follows:

D101: E3 W67
D102: U 68 03 ? (Not sure if it's a zero or a D)
D103: T68

Thanks in advance!

5

Projects, Designs, and Technical Stuff / Re: Help Identifying Power Connectors on RF Amplifier

« Last post by tooki on Today at 12:22:17 am »

… or are they just posts to wrap and solder wires to?

Yes, except that you don’t really wrap around them. They’re formally known as “turrets” and this is how you solder to them:

6

General Technical Chat / Re: What is this 8-knobbed IBM human interface device in a 1980's Boeing photo?

« Last post by tooki on Today at 12:17:39 am »

Wacom used to make these back in the day too. We had stylus/pen for it, the digitizer with the crosshair and also a regular mouse which didn't have a ball but an inductive sensor (optical mice weren't invented/common yet).

Wacom came late in the day, and was always focussed on its pen input, with mice and other gadgets being a secondary focus. They never really offered the high resolution of a Summagraphics, but they lead offer wireless handheld devices. That was their big innovation.

How do you figure? The Wacom tablet I bought in the mid-90s had the same 2540lpi resolution of the SummaGraphics, and as far as I know that was in no way new in that generation of Wacom tablets. The manual specifies 0.15mm accuracy with the puck, 0.25mm with the pen.

It might have been just the lack of a puck with fine crosshairs and a lens for the Wacom tablets, but I found them less effective for digitizing. Now you mention it, the actual steps per centimetre must have been competitive, so achieve their smooth fine pen drawing performance.

Can you be more specific? Are you saying that Wacom’s lens and crosshairs were less effective in some way than SummaGraphics’? Or that they didn’t offer a puck with lens and crosshairs at all? (Because they most certainly did.)

7

Buy/Sell/Wanted / Re: SALE (AU/NZ): Multicomp Pro MP710086 (Owon P4305 rebadge) at element14

« Last post by EvgenyG on Today at 12:13:38 am »

I will wait for another mark down, I think there will be more. If they go to $100-$120 mark, I'll get one for myself too.
The PSUs are selling fast now as they've discounted those to ridiculous prices. $31 bucks for a basic linear PSU? Unseen.
Also cheap are multimeters, but I already have too many. Test leads some are like 70c, bought a few, could not walk past.
Weller station yep same here I don't need a 3rd soldering iron lol

8

Power/Renewable Energy/EV's / Re: Flyback controller output voltage and amps under load

« Last post by thomasx on Today at 12:10:22 am »

Some improvements, I am now "only" down 2,5V at max load, 7A, from 12.2 to 9.7.

Looking at figure 9.21 in page 40 of the datasheet, it shows about 1 volt drop at a step to full load, (16V, 2.5A, 40W in that design).



So question is, should I also expect to get to a 1V drop at full load, or is 2.5V drop what I can expect as best in this case, with a 12V, 7A, 84 W converter?

Getting 9.7 volt from a 12 V supply just doesn't feel ok. Sure, I can up the low-load voltage to 13V and end up at 10.5V at full load, but it still doesn't feel good enough.

Losing 1V from 16V going from no to full load is a 6,25% loss. If I can get the same that would mean loosing about 0.8V in my case. I'd be happy with that, and 1V too. But more than that seems a bit much. Or?

https://www.ti.com/lit/ds/symlink/ucc28c54-q1.pdf?ts=1714685064113&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FUCC28C54-Q1

9

RF, Microwave, Ham Radio / Re: Generate FM using IQ inputs?

« Last post by radiolistener on Today at 12:06:22 am »

scale depends on audio sample range.
sin/cos functions already can handle any angle, but if your implementation don't know how to wrap it, you're needs to do it manually.

10

General Technical Chat / Re: Silicone vs. PVC measuring leads

« Last post by tooki on Today at 12:02:56 am »

Finely stranded? Easy. Really finely stranded? I have never seen it in PTFE.

For example, for 24AWG/0.25mm2:
Regular stranded: 7 strands
Fine stranded: 19 strands
Very fine:~ 40 strands
“Really fine”: ~65-130 strands.

There’s simply not much point in the higher strand counts because their flexibility is lost on the PTFE. 19-strand 24AWG PTFE is readily available, but I’ve never seen or heard of finer ones.