ZL DMR history
Members of the DATV Project Team recently met with representatives of several Government agencies to
discuss the final series of adjacent-channel spectrum compatibility tests.
Following the extensive series of field tests that have been carried out, and laboratory simulations using an output filter
consisting of a 6-pole cross-coupled bandpass filter plus a 6-notch filter, we expect a successful
outcome from the tests.
We are grateful to one of our corporate sponsors for the bandpass filter, and also to our member Steve ZL2ASF,
for the notch filter.
Stuff.co.nz carries an article featuring George Boorer ZL3PN, and discusses the return of access to 6 Metres (~54Mhz) with the shutdown of the conflicting Analogue TV network.
6 Metres - referred to as the 'Magic Band' by some - has had very limited use in New Zealand for many years, due to the close proximity of the Analogue VHF TV transmission.
The unmodulated CW carrier on 506 MHz has been turned off, on the completion of coverage testing. Our thanks go to everyone who provided a reception report.
A prototype 2-way splitter, being one third of the 4-way drive splitter, has successfully passed all tests. A similar prototype, a 2-way combiner designed for higher power operation, is now under construction.
Transmission of the unmodulated CW carrier continues on 506 MHz, with horizontal polarisation. Reception reports are welcome.
Four power amplifier modules have been constructed and tested one-at-a-time with the digital exciter. Their gain and linearity match within half a dB. The four modules will operate in parallel to achieve the licensed power.
A 4-way drive splitter and 4-way output combiner have been designed and are under construction.