Archive for the ‘DIY’ Category

Screenshots from HP 3585A Spectrum Analyzer via GPIB?

January 24, 2015 4 comments

I’m wondering if anyone reading this might have some experience and could chime in. I’m trying to make my HP 3585A spectrum analyzer talk to my Windows XP laptop over GPIB (488.1) with a National Instruments PCMCIA-GPIB card. I’ve been trying both the Keysight IntuiLink Screen Capture software (specifically for this instrument) as well as the KE5FX GPIB Toolkit‘s plotter emulator.

The drivers for the GPIB card are installed correctly. NI’s self-test suite passes; IntuiLink scans the GPIB bus and recognizes the 3585A on address 11, and KE5FX’s toolkit recognizes the GPIB card and is configured for F8 = the 3585A on address 11.

Sadly, Keysight’s app seems to do “something” when I ask it to pull a plot from the spectrum analyzer. It pops up a progress bar that takes a few seconds to finish and spawns a new window, but the generated image is totally blank. KE5FX’s app throws an unrecognizable error that’s something about the internal state of the app and exits instantly.

Anyone have any experience getting these things to talk to each other? Let me know, I’d love some pointers!

Update: It looks like I have a hardware issue with my GPIB interface, a new one appears to have solved the problem!

Free Your Keurig 2.0 with the Keurig Freedom Clip

January 10, 2015 Leave a comment

I wrote about how the Keurig 2.0 single-serving coffee maker came crippled by built-in DRM, locking you into using only “authorized” coffee servings in the new version of the machine a few weeks back. Enterprising users figured out how to use some scotch tape and the top of a Keurig-branded pod over the sensor to fool it into accepting any coffee serving, but even still, that’s not the most durable fix. Water, steam and a flimsy piece of tape aren’t a great mix and the last thing you want is having to fiddle with tape and optical sensors first thing in the morning just to get your fix.

It gets even better, though: the Keurig 2.0 DRM Freedom Clip! The coffee masters over at the Rogers Family Company, manufacturers of fully biodegradable single-serving coffee pods, figured out the special color Keurig uses to authenticate the cups and produced a clip that fits over the optical sensor with that color on the top face. It clips right in, once, and stays there forever. And the best part?


That’s right: it costs NOTHING, not even postage.

You should probably buy some coffee from them for making this hack possible, but this is fantastic and definitely worth checking out.

Thanks, Rogers Family Gourmet Coffee!

[Keurig DRM Freedom Clip]


Play Quake 1 on an Oscilloscope

December 29, 2014 2 comments

Pekka Väänänen must have been bored over the holidays, as he came up with a fantastic and fascinating new use for an oscilloscope and a laptop: playing a round of Quake on his Hitachi V-422 scope in X-Y mode.



After some pre-processing, apparently it’s a playable vectorized Quake game with a very unique display. Never seen anything like this before! Lots more details over on his site. Check it out!




Keurig 2.0 Hack: Make Any Coffee You Want

December 20, 2014 Leave a comment

I’m a bit late to the game for this particular trend on the Internet, but it’s definitely worth sharing. If you drink coffee in the mornings, you’ve probably heard of Keurig and their single-serving K-Cup style of brewing coffee. Pop a pod into the machine, push a button, and out comes an amount of coffee. The original version of these machines would happily brew anything you put into it, as long as it was the right size. Keurig also sold officially-branded coffee pods to use in their machines, but other companies made them too.

Enter the Keurig 2.0. Under the guise of delivering a better coffee experience, somehow, Keurig developed a special kind of ink to use on their K symbol on the lids of these new cups. A complex optical reflectivity measurement system ensures that you’re using an authentic Keurig coffee serving, or the coffee maker will refuse to brew your coffee. I assume they didn’t enjoy losing out on the revenue stream of providing the pods and thought this would be a good way to ensure they controlled the supply of coffee you could purchase.

Unfortunately for them, it turns out people really did enjoy the hundreds of unique varieties of coffee which Keurig didn’t authorize and provided a diverse selection of products which would work in the system. And it also turns out that, when you take away people’s choices in the name of greed, people will find a way around it.

But now, we have the Keurig Hack:

Simply peel off the lid of a “legitimate” Keurig-branded coffee pod, and scotch tape it to the optical sensor. Now, your coffee maker which was artificially crippled by the greed of the manufacturer will continue to brew any of the alternative coffee products dozens of other companies have produced.

I’ve been looking at buying a Keurig machine for a while – making coffee in the mornings is a bit of a pain, and this system really takes the hassle out, but I don’t care for most of the generic selections they offer. Now that this hack is out in the wild, I’ll probably pull the trigger in the next few months, since now I can use any kind of coffee I want. It’s a little expensive, but break-even point is about 3 months of Starbucks drip coffee on the way to work, so it’s easy to justify.

Happy brewing!

[Hack-a-Day] and [Lifars]

Boxed Kit Amps’ Gobo Stereo Amplifier Build and Review

November 26, 2014 2 comments

If you’re a subscriber to Nuts and Volts Magazine, check out my article in the December 2014 issue where I build, test and review the Boxed Kit Amps Gobo Stereo Amplifier, a great little desktop reference amp for any skill level in a beautiful laser cut blue acrylic case.


December 2014 Nuts and Volts

VD-1221 Replacement Substitute Diodes

November 25, 2014 2 comments

We’re lucky that these days you don’t need to stock very many diodes in the parts drawers for refurbishing most vintage gear – pretty much everything except for the main power supply rectifiers can usually be replaced with some combination of 1N4007 and 1N4148.

Some special diodes do still turn up, though, and they’re a bit harder to replace. Varactor diodes frequently turned up in the bias circuits of ’70s amplifiers where they were used to keep a very stable reference voltage for bias under changing temperature and current conditions. One commonly encountered varactor is the VD-1221, which turns up in the Sony TA-4650 VFET amplifier (3 diodes), the Sony TA-5650 VFET amplifier (4 diodes), and the rest of that VFET line. They also happen to not be the most reliable, and a failed VD-1221 will destroy all the VFETS in that channel. Those are unobtanium these days, so if you’re servicing any VFET amp it’s practically mandatory to replace those diodes as well.

Fortunately, in this application, they can be replaced with a pair of 1N4148s in series. Observe the correct polarity, but it’s as simple as that! It’s not the prettiest fix, but it’s cheap and effective.

VD-1221 1N4148

2 x 1N4148 in series will also work to replace the common VD-1212, VD-1220, VD-1222, and likely several other similar series diodes.

Destroying Hard Drives with a Drill Press

November 5, 2014 2 comments

I’ve had this stack of old hard drives lying around for a few years as drives become unreliable or I upgrade. There’s a 160GB, 320GB, two 400GB and a 1TB that failed recently. Most of them have never been even in my personal systems, just in servers, but a handful were my daily-use desktops over the years and have old business records, bank statements and the like on them. Secure wipes take a long time, and there’s no point really with them destined for the trash anyway.

Fortunately, that new drill press of mine can make short work of them.

Now, off to the trash. That’s probably the most fun I’ve had using the drill press yet, too.


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