[opendtv] Re: HD vs. 625 vs. 525 vs. 405

  • From: Terry Harvey <tjharvey@xxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Sun, 29 Aug 2004 14:25:25 -0700

The London station was built in 1935/36. The expansion of the service was 
post world war 2 when Kell's work was accepted.  Because the expansion was 
based on the prewar vision-sound carrier spacings, the Kell criterion was 
ignored for the whole existence of 405.

Afterall, if for 405 the Kell criterion was acknowledged after the war, 
there would have been more bandwidth available for expansion, but the 
change of vision-sound carrier spacing would have complicated the legacy 
receiver situation.

At 09:49 PM 8/29/2004 +0100, you wrote:
>I very strongly suspect that decisions were taken based on the number of
>channels needed for coverage and the total bandwidth available. When 405 was
>planned, only Band I was available.  That numbers game controlled it all.
>It's very tempting to post-justify the decisions, but in practice, such
>niceties weren't available at the time.

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