1835Re: [olivia] The 30m Band Utilization Chart -- 2 June 2011
- Jun 3, 2011Hi Ken,
What's your difficulty with "Center Frequency"? It's clear for AM, FM
and CW. Why is it NOT clear for Olivia or PSK31 or PSK125?
You basically use an spectrum of audio frequencies of a certain
bandwidth to modulate a SSB transceiver. Assume the transceiver is tuned
to frequency ftx. Assume the middle frequency of the spectrum is fma.
Then for USB your center frequency is ftx+fma and for LSB ftx-fma.
This is the stuff people learn to pass their licence exam for more than
50 years now...
73: Waldis Jirgens - VK1WJ - http://ilgonis.orgfree.com
Ken Meinken wrote:
> On Jun 3, 2011, at 2:47 AM, Waldis Jirgens wrote:
> > Hi All,
> > Nice chart however "dial frequencies" are absolutely meaningless since
> > with today's digital programs you can use whatever offset you like for
> > virtually ALL modes (including Olivia). I find quoting "dial
> > frequencies" more confusing than helpful.
> Then you can ignore it, can't you?
> > It leads to second guessing
> > why a particular person finds a particular offset for a particular mode
> > more desirable than another.
> Perhaps you overanalyze things?
> > There may be very good reasons to use a
> > "non standard" offset (like availability of sharp if filters).
> If you have a particular quirk like filters, then you need to work out
> your solution.
> > Even
> > worse: It discourages newcomers to digital modes, since "it's all too
> > complicated".
> I disagree.
> > When I arrange a digital sked on a particular QRG I
> > stipulate: "Center frequency of the signal" - that's clear!
> As clear as mud. I don't think you are simplifying anything for a
> newcomer. Is that USB? LSB? Have you ever had a SSB sked that spec'd
> "Center frequency of the signal"?
> What is the "center frequency" for PSK? 14070.15 USB seems to be a lot
> more clear to a newcomer than something more convoluted.
> Ken WA8JXM
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