2018-06-01

Ham radio awards 8: DXCC on 50 MHz !


Two recent LoTW confirmations for contacts on 50 MHz (S01WS and 7X2TT) got my DXCC total to the magic number 100! Actually I have worked a few more on the Magic Band, but they confirm only with paper QSL cards "via direct ($$$)". 

This will be my 9th DXCC award certificate, plus an endorsement for the 5B-DXCC plaque!


 

2018-05-31

2018-04-29

DAB/DAB+ digital radio in Thessaloniki, Greece

In a previous post I discussed the ERT DAB+ multiplex covering Athens, Greece. Recently the government controlled broadcaster ERT started transmitting a second  DAB+ multiplex from their transmitter site on Mt Hortiatis, near Thessaloniki. (HGRS87 coordinates: 423700, 4494181; WGS84 coordinates 40.5975 N - 23.1000 E; 871 m ASL).
 

The second experimental ERT transmssion on 174.928 MHz (Channel 5A) covers most of Thessaloniki and part of Central Macedonia Region. The multiplex contains the following audio streams:

"PROTO" (136 kbps,  AAC)
"DEYTERO" (136 kbps, AAC)
"TRITO" (136 kbps, AAC)
"ERA SPORT" (128 kbps, AAC)
"KOSMOS" (136 kbps, AAC)
"Voice of Greece" (96 kbps, AAC)
"ERA 7" (64 kbps, AAC)

The channel characteristics were logged in the afternoon of Sunday, April 29, 2018 using a Perstel DR70tc portable FM/DAB receiver at various locations in downtown Thessaloniki. 


A second multiplex under the name of "Sigmacom DAB+" is also transmitted from an unknown location in or near Thessaloniki on 225.648 MHz (Channel 12B). On April 30, 2018, it carried six private stations:

"YELLOW 92.8" (96 kbps, AAC)
"COSMORADIO" (96 kbps, AAC)
"KALAMARIA FM" (96 kbps, AAC)
"MORE RADIO" (96 kbps, AAC)
"AROMA FM" (48 kbps, AAC)
"PLUS RADIO" (96 kbps, AAC)

This seems to be an experimental transmission by local rado equipment supplier Sigmacom Broadcast Ltd. According to the official Digital Radio Allocation Plan for Greece, channel 12B would carry the 5th DAB multiplex for Thessaloniki area.
 

 

     

2018-02-26

2018-02-24

DAB/DAB+ digital radio in Greece





A few weeks ago, the government controlled broadcaster ERT started transmitting a DAB+ multiplex from their transmitter site on Mt Ymittos, near Athens (HGRS87 coordinates: 483892, 4200920; WGS84 coordinates: 37.9583 N - 23.8183 E; 945 m ASL). Before that, the Minsitry of Digital Policy, Telecommunications and Information had published two relevant ministerial decisions in the Government Gazette. Decision 169/2018 defines the allotements and frequency allocations for DAB broadcasts in VHF Band III (174-230 MHz) and authorized a number of transmitter locations. Decision 170/2018 issues a license to ERT for nationwide DAB+ broadcasts on one frequency in each allotment.

Currently an experimental ERT transmssion on 227.36 MHz covers only part of Attica Region. The multiplex contains the following audio streams:
  • "PROTO" (136 kbps,  AAC)
  • "DEYTERO" (136 kbps, AAC)
  • "TRITO" (136 kbps, AAC)
  • "ERA SPORT" (96 kbps, AAC)
  • "KOSMOS" (128 kbps, AAC)
  • "Voice of Greece" (96 kbps, AAC)
  • "ERA 7" (64 kbps, AAC)
The channel characteristics were logged in the afternoon of Satruday, February 24, 2018; they may change over time while ERT engineers experiment with coverage and sound quality issues. 

Voice of Greece is also transmitted at irregular times, usually during late nights, in short wave, on 9420 kHz.  

"ERA 7" transmits audio from the sessions of the Greek Parliament. 

"TRITO" is supposed to transmit high fidelity music, however the current bitrade is inadequate, as 192 - 256 kHz is the minimum acceptable bitrate for this purpose.

My vintage MagicBox Clarus Plus DAB/WiFi digital desktop radio receiver can receive all seven channels with its whip antenna, however the signal strength is weak and the error rate relatively high.

For general and technical information about DAB, access to the relevant ETSI standards and other updates, visit the WorldDAB Forum at: https://www.worlddab.org/