Friday, 15 May 2015

60 m band

As a result of a request from VERON ("Vereniging voor Experimenteel Radio Onderzoek Nederland") to "Agentschap Telecom", in the Netherlands there is a chance that part of the 60 m band (5250 - 5450 kHz) comes available for experiments in the near future. This band, located between 40 and 80 m, is very interesting to do (QRP) experiments.
Although the operating frequency is below 10 MHz, the common voice mode used in the 5 MHz band is USB.

In advance of the release of the bandsegment I thought about a 5 MHz transverter. When using a 21 MHz transceiver, with a 16 MHz local oscillator, a transverter could look similar to the design shown below.

Friday, 8 May 2015

70 cm WebSDR

Since begin this month a UHF 70cm WebSDR has been activated.
The 70 cm antenna of the Software Defined Radio has been located in the
centre of the Netherlands, the Gerbrandytoren.
The frequency range of the receiver is 430.000 - 432.000 MHz
The URL to access the receiver via the internet is:


Sunday, 3 May 2015

Hybrid TV PCI Card

If you want to watch life TV on your PC you might install a DVB-T USB stick these days.
A couple of years ago, when those USB sticks were not available, there were computercards that did the job.
Last week at kingsday we went to a fleemarket and found an unused Hybrid TV tuner card from Zolid (manufacture date 2009).
In the box, apart from card and software, an antenna, remote control and IR-eye had been included.
This morning I installed the card in an old Pentium IV pc that runs with Windows XP.
After installation of hard- and software (driver and "Total Media") I now can watch "free-to-air" transmissions of DVB-T stations (NPO1, NPO2, NPO2 and a local station) and listen to some radiostations. Decoding of "Teletext" signals works fine.
Besides the reception of DVB-T transmissions there is an option to watch analogue signals. Although the max receive frequency is 864 MHz, this option might be interesting for further experiments. 

Components used on the TV card:
-TDA18271 (tuner)
-TDA10048 (demodulator)
-TDA8290 (analog IF demodulator)
-SAA7131E (A/V decoder/pci interface)

                                                  Zolid TV card

Zolid TV tuner card

                                                      TV card installed in PC (aft card)

                                                   "Total Media"  up and running