22 February 2015

SOTA: gathered season bonus points this weekend

It's the middle of February, sunny outside and I'm in an outdoors mood - of course some SOTA will happen. As in this time of year the mountains are covered in snow, I decided to go for two low-effort high-reward 6 point summits I've visited before - only this time I will also collect the seasonal bonuses. These are YO/EC-252 Piatra Arsa and YO/EC-241 Fitifoiul and more details about them you can find in the previous activation article.

First in line is YO/EC-252 Piatra Arsa and this time the 10-minute walk from where I could park the car to the lodge at the base of  the mountain turned into a 30-minute one, since because of the snow I couldn't park on the side of the road, let alone enter the road leading to the lodge. So I had to park further away - in a small motel's parking lot, plus once I entered the woods the snow wasn't exactly making things easier.

09 February 2015

Raspberry Pi 2 freezes when photographed

The all new Raspberry Pi 2 is the new maker's sensation, sporting 6 times more performance and 2 times more memory than the previous model, keeping the same affordable US$35 price label. And this is not everything, Microsoft is also offering a free version of ARM-compatible Windows 10 for it (yes, you just read a sentence that includes "Windows" and "free"). These are great times if you like fiddling around with hardware, software and electronics.

There is however some sort of a funny issue with the Raspberry Foundation's new creation: when exposed to strong infrared light (such as that from a Xenon photocamera flash or a small red laser pointer) it just freezes and crashes. The source of this problem has been identified as a small PWM voltage regulator that powers the processor and the memory - NCP6343 made by OnSemi, wich is dubbed U16 on the small Raspberry Pi 2 board - I dare you to find it in under 1 minute in the image above (click to enlarge).

14 January 2015

About the Elecraft K3 vs Kenwood TS-590 debate

I was just reading earlier Simone IW5EDI's article about a short overview on the K3 and the TS-590. This is an interesting debate as they are some of the popular high-performance transceivers on the market today, and I would like to share my views.

13 January 2015

HF-P1 portable antenna review

The HF-P1 is a lightweight antenna with HF to UHF coverage, designed for portable operations where size and weight are important. Thoughtful design and the use of quality materials make it look like a reliable choice for outdoors aficionados, but is it so ? Read further to find out.

Looking for the HF-P1 name, not many results popped up - it's not a very widespread brand name. The HF-P1 is sourced in Germany and you can find it in amateur radio shops there, plus probably a few other countries in the EU. It's not clear who is the manufacturer as the german websites don't list one and the product comes in a whitebox, but it seems identical to the Superantennas MP1B (US made). The small leaflet inside just says "HF-P1 portable HF antenna", so that doesnt help much.

The leaflet also claims that this antenna can cover 3.5MHz to 440MHz, a bold claim that got easier to understand once I saw what it's all about. The design is optimised for small size, reduced weight and versatility, being able to form a resonant antenna system on almost any frequency between 3.5 and 440MHz by the use of various fixed or adjustable elements and coils.

HF-P1's leaflet contains the minimal information needed to get you going

05 January 2015

Testing the Ultimate 3 WSPR beacon

Some time ago Aurel YO3IBZ borrowed me his Ultimate3 to try and replace the AD9850 DDS with AD9851 so we could make it into a useful 6m WSPR beacon. Unfortunately I only managed to make it work at low frequencies (below 10Mhz or so), and even though Hans (who created the Ultimate3) was very supportive with firmware and such, I came to the conclusion the easiest way was to just force the AD9850 to work at 50Mhz.

This is not really an issue, it's just that above ~25MHz the AD9850 output level starts decreasing and spurs start to appear. Output level is not really an issue because there is some amplification after the DDS, and the spurs above 50MHz should be largely stopped by the DDS onboard low-pass elliptic filter (cutoff around 72MHz) plus the other low-pass filter I've attached to the output (cutoff around 55MHz).

So I just strapped the new filters I made (not only for 6m, but also for 10m and 15m) into the sockets of the Ultimate3 and found a nice metal casing for it:

31 December 2014

Happy new year !

Thank you all for visiting my blog in 2014, may all your wishes come true in 2015 !

25 December 2014

SOTA activation: YO/EC-520 Seciu peak

After more than 2 months of ugly weather - wich included a full consecutive 30 days of overcast sky, the days around Christmas are finally taking a turn on this side of the world. The Christmas Eve morning caught me in my hometown of Ploiesti, with a long list of chores ahead; luckily, outside was the clearest and bluest sky I've seen in months, and I immediately thought of the SOTA bag I was carrying in the car and the new antenna I had to test. So after helping my father with a few things around town, I took off for the closest and most accessible SOTA peak: YO/EC-520, Seciu peak.

This little guy is only 406m tall (1 point, no season bonus) and is one of the smallest I've ever activated, the only one below it being YO/MM-005. It is known thanks to the famous wine maker and touristic complex right on top of it "Casa Seciu", usually reserved for the high-ranking members of the communist party before the 1989 revolution. Now it's open for everyone and I had the chance to visit it about 3 years ago, take a tour of the wine cellars, taste their excuisite cooking and purchase a few unique bottles "for closer examination".