Search This Blog

Friday, September 16, 2011

Wave of the Future

We have had an encouraging learning experience during our DRM test transmissions. The spectrum analyzer display shows the typical "Bart-head" waveform that a DRM broadcast creates. TX6 was able to acheive a "shoulder depth" of at least 32dB, which is quite good.
There are still bugs to be worked out with the data being sent from the content server to the modulator in the transmitter. These bugs are creating occasional breaks in the audio. However, the sound quality is amazing for a shortwave broadcast. We have received listener reports from Japan and Australia. The main beam of the 75KW signal was actually headed toward India.  You can go to to hear the signal that was received in Japan.

Friday, September 2, 2011

More Testing

A few more accomplishments at KTWR…
75% Power Test
With the Antenna connection completed, we are now able to test The Thomson Transmitter at higher power. On August 31 we were able to bring the Thomson transmitter to 218KW. The transmitter ran smoothly with very low reflected power.

Content Server Test

The Transmitters at KTWR Guam are two Harris SW100 Transmitters (100KW), one HCJB HC100 Transmitter (100KW) and now the two reconditioned Thomson TRE2326 transmitters (250KW).
We have had an ongoing project to upgrade the HC100 Transmitter to DRM (Digital Shortwave) for several years. One of the devices needed to broadcast digitally is a content server which formats audio into the correct form of digital audio.
We have not been able to work on the HC100 upgrade for a long time, due to the Thomson transmitter installation and other complications. We felt it would be a good idea to test the content server so…
We configured the content server to stream Digital content to the new Thomson transmitter because the Thomson is already DRM capable.
Here are the results.
Sept 2nd 75KW DRM

We are very Happy to report the Content Server Works Very Well!!