29 June 2012

Raspberry PI: ordered

The "invitation to order" email came one day late and I have just paid for my RasPI. Order #127xxx, despatch expected within 11 weeks (or 77 days, or mid September).

(up here is a countdown widget in Flash, in case you don't see it)

27 June 2012

avreal32 and lock bits

I feel dumb. I was expecting to see AVR's lock bits LB1 and LB2 amongst FUSES in avreal32 programmer, so I never saw that there is a dedicated option for preventing the readback of the chip content.

The command for locking an ATmega168 is (add your usual programmer definition and options):

avreal32 +mega168 -l2 (programmer parameters)


22 June 2012

SDR# on a Centrino CPU

Not a big achievement, but I want to report that I could use the RTLSDR dongle with SDR# on a laptop running WinXP with an Intel Centrino 1.6 GHz CPU. I have reduced the sampling to 1 Msps and the machine was running at 50% CPU: not bad for a 2004 computer! I listened to both WFM and SSB signals. There is probably room for a higher sampling rate, but keep in mind I have been listening to decoded output and not fed it over to another software (which in turn uses its share of CPU cycles).

20 June 2012

23cm activity

These heard stations on 23cm SSB are some of the local big guns. Well, not so local given the DX distance of 136 km and my antenna consisting of an indoor dipole! But the HB9's were using 200W or more...

HB9BCD at 136 km

I1NDP and another QSO at 1'296'250 kHz

HB9SV at 136 km.

I do not like those aliasing products (or intermod?! or receiver overload?!), which then disappeared when I fiddled with SDR# settings. That effect requires further investigation.

My RX setup was not QRP either, since the i5 core laptop eats up a good deal of energy too (50W or so). I have already shaped up a biquad antenna. Now it needs a reflector and a support, then I am ready for the next 23cm event. Unless I manage to get a signal out of that SAT-TV PLL...