No apologies needed. Actually all this speculation and
its associated debate is fun and I believe serves as a
useful feedback mechanism to the folks at Ten Tec who
I'm sure watch this reflector quite closely.
Duane
N9DG
--- Ron McKean <wd5fun@earthlink.net> wrote:
> Sorry, I may have mixed conversations with other Ten
> Tec people into the
> information from Scott. I have been told that the
> main receiver will use
> both crystal and DSP filtering. But, all of the
> speculation is useless,
> because I am sure there will be several design
> changes before release. I
> will be talking to some Ten Tec folks at a hamfest
> Saturday and will get a
> definitive answer.
>
> Ron
> WD5FUN
>
> -----Original Message-----
> From: tentec-admin@contesting.com
> [mailto:tentec-admin@contesting.com]On
> Behalf Of Duane Grotophorst
> Sent: Thursday, February 28, 2002 5:04 PM
> To: Ron McKean; N1EU; tentec@contesting.com
> Subject: RE: [TenTec] Orion prototype
>
>
>
> --- Ron McKean <wd5fun@earthlink.net> wrote:
> > You are absolutely right. Scott, stated in his
> > informational release that
> > the Orion would utilize both methods. He also
> said
> > that the main receiver
> > (using the crystal filters) would be ham band
> only,
> > so I assume it will use
> > a crystal mixed oscillator like the Omni V and VI.
> > The sub-receiver will be
> > full coverage and use only DSP technology.
> >
>
> I didn't get the impression at all that the main
> Orion
> RX is going to be crystal filter based, at least not
> in the sense that the Omni VI et al have been.
>
> From Scott's 25 January post:
>
> "Main receiver is amateur radio bands only,
> utilizing
> both analog and IF-DSP stages, 10-160 meters. Sub
> receiver is IF-DSP, general coverage."
>
> Nothing in those two sentences implies that the main
> RX will not be DSP based, in fact plainly says it
> will
> have DSP. I interpreted his comment to reflect that
> there will be a mix of analog elements and DSP in
> the
> IF chain. Much the same as Ten Tec's DSP radios to
> date already are. This makes good sense because 130+
> dB dynamic range A/D devices are rather rare or at
> least very expensive. Im sure that much of the
> top-notch performance will come from choosing more
> capable analog devices in the RF/IF chain before the
> signal gets digitized.
>
> What I did get out of Scott's posting was that they
> will likely have relatively narrow band pass
> filtering
> for the ham band frequency ranges. Relay switched?
> Perhaps combined with this will be a synthesizer
> design that is similarly narrow (tuning range),
> again
> a methodology that was already used in the Omni V
> and
> up series. But I also doubt if it will be a crystal
> mixed scheme like the later Omni's for cost reasons.
> There are several really low phase noise synthesizer
> chips out there already that rival crystals.
>
> Did you realize that the K2 and Pegasus/Jupiter
> share
> the same Motorola synthesizer chip? One has
> exemplary
> phase noise specs and the other is mediocre by
> todays
> standards. The low phase noise K2 doesn't use a VHF
> up
> conversion scheme whereas the Pegasus/Jupiter does.
> The main reason up conversion became so appealing to
> designers was to provide for continuous no gap HF
> coverage. The main Orion RX will not do that, hmmmm.
>
> Bottom line is that current crop of DSP IF radios
> aren't being limited so much by the DSP design
> issues
> themselves. They are instead mostly limited by other
> architectural design issues that would/do impact
> analog only designs equally.
>
> 73,
> Duane
> N9DG
>
>
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