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 …


Weird man

I could hardly describe the pleasure of finding my mailbox full of magazines, brochures and thick envelopes. It’s psychological mojo probably goes back in my childhood days, when I was expecting my Topolino subscription, a magazine that my mother managed to get for me with some crazy efforts and connections. For those of you who do …


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, …


Thank you, Mouser and Texas Instruments !

Mailbag today. Guess my surprise when I found this in my mailbox: It’s always nice to receive snail mail. Paper mail. Envelopes, magazines and newspapers. That’s why I try to subscribe to receive printed editions of all magazines of interest for me. Some time ago I signed a promo email from Texas Instruments in cooperation …


“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 …


2014

Back from a long vacation. Then I resumed my office work. A lot of things to do so I neglected this blog for a while. 2013 went in smoke. Not a very nice year, but not too tough either. However, one year I was not very fond of. I am looking back to some stakes …


Agilent DSO-X 2002A driver for Mac OS X

Update, October 2nd, 2014: a more recent adavancement in running SCPI on mac, can be found here. Update, December 10th, 2015: Updated terms, changed Agilent to Keysight. 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 …


Ham Radio certification passed !

I added a new category/ topic on this blog because last week I successfully passed my Ham Radio certification ! This is something I wanted to do for a long time but had not much time to study and prepare for the exam. One of my relatives was a long time experienced class I Ham …