Thursday, December 20, 2012

Testing the digital voice with Ed VK2JI

Another interesting test.  Ed and I tried the 20 m (14236) and could not make it. But then we QSYed to 40 m and it worked well.

OK it worked... we had some significant QRM

  

Please note the vertical lines on the side of Ed's signal... that is somebody's switching power supply from Plasma TV at or near of my QTH.


Here you see Ed's pretty strong signal on the computer screen.  Free DV interface.
 

Here is clean and strong signal as image on my Elecraft P3 panadaptor.  The QRM lines are not as prominent as on the first image.

Conclusion at this stage:
  1. The signal needs to be reasonably strong.
  2. Static crashes do "upset" the decoding.
  3. It is quite resilient to man made interference (QRM)
  4. It is quite sensitive in a way of audio settings (in and out) of the encoder/decoder are set on the computer sound card.
  5. It is sensitive to netting - the TX and RX frequencies most likely need to be very close.
  6. It is "good fun" to test something so very new.
I'd love others testers opinions.

1 comment:

  1. Great stuff Patrick. I'll be up for some more tests over the xmas period if you're about.

    73s
    vk2tpm

    ReplyDelete

Old guys visiting Cockatoo island.

...