News

 

 

 

Digital Television Tests – Bulletin No.6

Transmission of the unmodulated CW carrier continues on 506 MHz, with horizontal polarisation. Reception reports are welcome.

Adjustment and testing of the digital modulator is complete.

The prototype power amplifier module has been constructed and is now undergoing quality testing. Once testing is complete another three modules will be constructed. The four modules will operate in parallel to achieve the licensed power.

Digital Television Tests – Bulletin No 3

Since update number 2, the quality of the prototype exciter and power amplifier, has been tested using professional test equipment.
These tests used both an unmodulated CW carrier, and a 7.6 MHz wide modulated spectrum, both centred on 506 MHz.
Both items performed better than expected and did not require any adjustment.

We are now working on getting the antenna system ready for the CW test transmissions.

Digital Television Tests – Bulletin No 2

Update number 1, as at 21st January, was published in January Q-Bit magazine, recently posted to members.

In summary, the update included a block diagram of the digital test system and discussed the various factors influencing the quality of the radiated transmission, such as the exciter quality, adjustment of the power amplifier, and the impedance matching of the output filter and antenna.

DIGITAL TELEVISION BULLETIN No 1 - RSM grants the first Digital Amateur TV (DATV) Licence.

New Zealand Radio Spectrum Management (RSM) has granted the first Digital Amateur TV Licence to NZART Branch 74, The Wellington VHF Group, for use at its main station located on Mount Belmont, in Wellington.

The main features of Licence 236831 are:

  • Digital TV Channel 25 (DTV25)
  • 502 MHz to 510 MHz
  • DVB-T format
  • 7.7 MHz emission bandwidth
  • 100 W mean effective isotropic radiated power (eirp)
  • Horizontal polarisation
  • The licence is valid for an initial period of 6 months, from 1st January 2013 to 30th June 2013.

    Doug Gorman Memorial Frequency Measuring Contest 2012 – Results

    The results of the NZART Doug Gorman Memorial Frequency Measuring Contest 2012 are presented below. These results are provisional and have been checked carefully but if you think an error has crept in please let NZART HQ know as soon as possible.

    Propagation conditions this year did not favour precise measurement, but congratulations to winner Mike ZL4OL who did a brilliant job using off-the-air calibration.

    The format of the results is Branch (if noted in contest entry) Name Call Average (Hz) Standard Deviation (Hz) Equipment and signals (if noted):

    OVERALL

    Doug Gorman Frequency Measuring Contest Monday 1st October 2012 at 2100 NZST - Note new date

    The 60th annual NZART Doug Gorman Frequency Measuring Contest supported by the Wellington VHF Group will be held slightly later this year than usual on Monday 1st October 2012 at 2100 NZST.

    The rules will be the same as last year based on feedback from contestants. Please read the rules carefully.