BATC Forum

I just published a DATV article for my local radio club, OCARC, that is intended to explain the factors that control the RF bandwidth for DVB-S transmissions. The promise of DATV to deliver video in “less bandwidth than analog ATV” is a great goal, but I could not find information explaining what is involved - all in one place.

The name of the article is:
“TechTalk #76 - - DATV - Understanding Symbol-Rates, FEC, and RF Bandwidth for DVB-S”

It can be found at:
www.W6ZE.org/DATV/TechTalk76-DATV.pdf

I hope others may find it useful.

73....de Ken W6HHC (W6HHC@ARRL.net)

I just updated the TechTalk76 article to more thoroughly cover the different ways of describing RF Bandwidth when using DVB-S and QPSK modulations.

I have discovered (love that Google) that there are three different methods for commonly describing bandwidth:

1) “minus 3 dB” bandwidth method

2) "occupied" bandwidth method

3) "allocation" bandwidth method

It is my opinion that if you are trying to determine how many DATV repeaters will fit into a band plan "shoulder-to-shoulder" (especially on the same hill top or tower), then hams should use the "allocation" bandwidth method.

The updated TechTalk76 article can be found on the OCARC website at:

http://www.W6ZE.org/DATV/

I certainly would like to hear from other hams on this DVB-S topic.

73....de Ken Konechy W6HHC (W6HHC@ARRL.net)