25 May 2010

Looks like ...

... Italy will get again a 70 MHz (4m) allocation in 2010.

I need to build an antenna again! And maybe a power amplifier for my 100mW CW TX.

Stay tuned!

17 May 2010

XTAL choice for 455-12 DRM converter

14060 kHz / 32 sounded good.

So does 7030 / 16.

How about 7040 / 16 then?! It gives 440 kHz, that is even closer to the I.F. of 455 kHz.

I should add this feature to my xtalfind.pl utility.

I also tried out the receiver and with my finger as antenna a DRM transmission was clearly audible on 9.8 MHz band. So I'll proceed with this IF downconverter project.

10 May 2010

XTAL L.O. for DRM 455-12 converter

The idea of a free-running LC oscillator for my 455-12 DRM converter kept me worried for a few days. With the help of a calculator I found out that:

14060 kHz / 32 = 439.375 kHz


455 - 439.375 = 15.626 kHz

So, with a binary counter/divider I can get a LO acceptably close to 12 kHz. I know that DReaM software will decode a DRM signal centered at 15.6 kHz.

Where did I store that 74HC4060 ... ?!

03 May 2010

I QRP Bullettin Spring 2010

It's finally out. The Spring 2010 issue of the I QRP bulletin. This edition is all in Italian language and I contributed with two articles. The former should appear on SPRAT too, while the latter is a World premiere, instead!

Download it here.

Please note. Article submissions are welcome for future editions of the bulletin. Even if not in Italian language, they can be translated by some native speaker.