I ordered some ferrite beads for a RF circulator project I currently work on but these might also be very handy for the SWR bridge project. These are extremely efficient for RF supression, or at least this is what they say.
Boards for prototypes
For low frequency projects, a fast way to prototype is using a bare PCB and scratch some dividers that allow “manhattan” style prototyping. I am especially very fond of this prototyping technique and I believe that PCB design should be avoided in the early stages of prototyping. Jim Williams was an artist in such designs. […]
OCXO tests
A couple of months passed since I purchased two 10 MHz OCXO modules from eBay. And, to my shame, I didn’t even tried these. Yesterday I did a quick test and the devices are spot on. Both measured on my TTi TF930 3GHz frequency counter: The OCXO needs apx 10 minutes for proper warm up […]
Hamfest Friedrichshafen 2016
The international amateur radio exhibition is the platform for ham enthusiasts from all over the world.
Electronics from China — Pixie CW
Power supply: DC 9v – 12v Antenna: 50 ohms, is not balanced, 7MHZ band, standing wave ratio below 1.8 Receive the static current: 10 mA @ 9 v Transmission power: 0.8W @ 9 v, 1.2W @ 12 v Frequency range: 7.023 MHz launch, receive 7.023-7.026 MHz (7.023 MHz crystals) Stray (harmonic) inhibition: – 20 db […]
Electronics from China
I am pretty pleased by the outcome of my commercial endeavours on eBay. Purchasing seems to be a pleasure; until now — with just one exception — I was spared from any nasty experiences. After several small items that I ordered in part for my curiosity to evaluate speed and quality of shipments from chinese suppliers, I […]
A Weekend Project
Not much to say today. For some time I wanted to tear down and clean my old Panasonic radio casette player. I am very fond of this device. A small and relaxing weekend project.
More about zombies and XCode
Some time ago I did a very short introduction about enabling zombies when debugging in XCode. As a refresher, zombies is a Cocoa feature that turns any object going to be deallocated into a NSZombie instance. This will not prevent your application from crashing, but instead of getting a stack dump from Xcode that is a […]
Some thoughts on the Responder Chain
I had a lot to do these days and did not manage to keep up with the blog. Very busy time at the office before Christmas. Luckily, I’ll get my vacation soon by I swear I will not spend it on much anything else than reading paper books. And books which are not about programming, […]
XCode 5 LLDB Debug Assertions
One situation when a debugger might not be the first option is when you are not sure where does a program has a bug. One way you can check whether your assumptions are truly what is happening in your code is by using assertions. What assertions let you do is express one particular assumption and […]
SCPI on Mac
Some more days passed and some more finishing touches added to my MacSCPI app. It is entirely dependent on hooking the device via the USBTMC driver, but it works fine and is stable: I had some problems with buffer padding and the output it is still not 100% gibberish–free , but I assume I have to play with […]
USBTMC driver for Mac
After some head banging, I finally managed to send SCPI commands from my Mac to my Agilent (Keysight) DSOX2002A. I’ve worked on this since december last year. Almost a year, but I did not spent a sustained amount of effort. I did it just during my free time. I still have a day job that […]
XCode 6 — new debugging features
As one of the goodies launched during current WWDC 2013, Apple has released a developer preview of Xcode 5 and detailed some of the new features it offers such as Automatic Configuration, Test Navigator, Bots, Auto Layout, Asset Management, Debug Gauges, Source Control, and more. Looking over some of the videos of the WWDC Sessions Videos, […]
Writing serial drivers for OS X (1)
At least one thing can be improved on Mac Dev Center: the code sample repository. I am not talking about documentation. In this particular case, there’s not much new to write about. The I/O Kit documentation (grab the pdf while it is stil there) is sufficient. On the shelves are tons on books about C and […]
Rigol Spectrum Analyzer !
I’ve kept drooling for this for several years. Today I finally got it ! Moreover, it seems it is fully-option enabled, which is kinda weird because I haven’t ordered for such. However, here it is: the Rigol DSA 815 TG Spectrum Analyzer with tracking generator. This will enhance my lab’s capabilities in RF electronics and […]
C#, SCPI and Keysight (Agilent) DSO-X 2002A
This post is a relic. The initial draft dates back in January 19, 2013. And was left as draft ever since. Past couple of days I was busy — among other things — learning a new programming language, C#. 🙂 Ok, here’s the deal: my scope (KeysightAgilent DSO-X 2002A) is SCPI–compliant device. If you remember, the reason behind […]
__attribute__((packed))
The __attribute__ keyword in GCC allows you to specify special attributes on variables, functions, and types — including struct and union definitions. It is a non-standard compiler extension that gives you fine-grained control over how the compiler handles memory layout, alignment, calling conventions, and more. This article focuses on one of its most commonly encountered […]
LTSpice Parameter Sweep
While designing/ working on my APRS project, I used LTSpice IV for some simulations. For those that don’t know, LTspice IV is a high performance SPICE simulator, schematic capture and waveform viewer from Linear Technology. It is a freeware and can be downloaded from this link. Versions for my both platforms exist, Win 7.0 and Mac. […]
144.8 Mhz TX for APRS (3)
This is a quick update post. The road I took with this little project is slowly getting to a dead end due to what it seems to be a lack of available crystals for 144.8 (like 48.26 or 28.96 MHz, for using the third or fifth harmonic). I believe that, currently, all APRS modules are […]
Simple stuff: viewDidLoad vs. viewWillAppear
I was coding today for a small project I have. A very simple iOS application that has a very simple storyboard, two different paradigms for iPhone and iPad, but very, very simple. While coding I was struck by the fact — frequently forgotten — that we tend to ignore the obvious. Ok, here’s the deal: take one […]
144.8 Mhz TX for APRS (2)
More work today and yesterday on this project. Still locking on 144 MHz, but this is normal, the crystal I used is a 48 MHz overtoned, working on the third harmonic in this case, thus spot on 144.0 MHz: I managed to clean the output, at the expense of transmitted power. I used a 7-pole 2m bandpass […]
144.8 Mhz TX for APRS
Been busy at work lately, but still had some time for myself. Latest idea: a low-cost APRS beacon, done with a classical 144.8 Mhz TX and a μController. AX.25 on air. Automatically. So these days I’ve been busy making this: Winding coils, soldering, measuring. Fun. The frequency is remarkable stable, given the rudimentary nature of this. For example, […]
“Auto Layout on iOS Versions prior to 6.0”
A short reminder, because I ran into this today and Xcode’s very poor at providing you useful verbosity when debugging Auto-Layout stuff done in Interface Builder. Sometimes (Xcode 4.x and 5.x) you might get the following errors when building an iOS project: Going to each error does not help much. Debugging IB auto-layout errors is […]
The Indestructible LDMOS
Mailbag today 2 ! This time from NXP. OMFG, look what I got ! This baby will definitely end up in a power RF amplifier for my Ham Radio fun time. This will be a project. THANK YOU NXP ! Got them both today ! And I have to tell you, the girls and guys […]
IOUserClient and IOExternalMethod
While developing the OS X driver for my Agilent DSO-X 2002A oscilloscope, I ran into a topic that I found to be poorly documented. It is about interaction with a device driver. There are several ways to communicate with a device driver from client space (the application). One is by modifying driver properties. This method requires […]
Agilent DSO-X 2002A driver for Mac OS X
December again, another year passed. Traditionally, this is a month when I am taking a long break. But I was up to something in the past days and I wanted to share. I have created a driver for my KeysightAgilent DSO-X 2002A oscilloscope. Maybe not a big deal, but huge for me because this is […]
Writing a (working) USB driver for OS X
For some time I was struggling with an ambitious project, to write a Mac driver for my Agilent DSO-X 2002A oscilloscope (see here). The reason behind this is SCPI and the opportunity to reach fresh perspectives in computer–measurement instruments’ integration. However, it was not an easy way. More of a reverse–engineering project, was very time–consuming […]
Low Power Digitally-controlled Dual PSU
It comes a moment for any electronics hobbyist to build a power supply unit. Probably is one of the most useful and basic projects that you can go for. Well… one can easily buy those, but what’s the fun then ? However, the majority of PSUs available on the market are high-power (high-current) PSUs. With […]
Missing WordPress Link Manager
WordPress users that updated the blog platform to version 3.5 might have observed that the link manager is missing from the admin pages: It seems that WordPress announced this as one of the major core changes when they released version 3.5: One other major change is the Link Manager. If you’re using it, you’ll want […]
Changing FTDI descriptors
I was struggling for some time to make my Mac communicate by USB with Arduino. It is part of a larger project of an USB-controlled Lab PSU that I am currently in prototype stage. Part of these problems solved when I finally realized that you cannot use an Arduino as an USB controller simply because […]