Category: Blog

Bye, bye Vacation !

I took a break for almost two months and it was so good ! Away from any disturbance, just us, the Sea and some books. The first couple of weeks slipped away almost unnoticed. There’s something special about Mediterranean… exerts an irresistible charm. Laying on that sea’s shore I can just close my eyes 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 …

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. …

Red and Green

This will be a very short post. And only for the blog. I have a sweet spot (call it idiosyncrasy) for stationery. I mean, some people do heroin, some do alcohol, some do Oprah. I am addicted to stationery. Put me in a stationery shop — you can leave me there all day (give or take), …

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 …

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 …

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 …