[TenTec] Orion 9 MHz filters

[Tom A]

Thanks to all for the replies!.

I agree.. I think I'll sit back and wait for some feedback from the guys who
get their Orions before me and hear what their thoughts are.

I have no complaints about the filters in my Omni-V.9 so I suspect it will
eventually be a matter of "Go ahead...add the 1.8, 500 and 250".

Tom K2TA
Greenwood Lake, NY
tom at k2ta.com


----- Original Message -----
From: "N4PY" <n4py at qvssoftware.com>
To: <tentec at contesting.com>
Sent: Friday, March 07, 2003 3:18 PM
Subject: Re: [TenTec] Orion 9 MHz filters


> Well said, Duane.  To put it yet another way, the purpose of the 9 mhz
> filters is to reduce or eliminate DSP overload caused by very strong
> adjacent channel signals not in the DSP passband.
>
> Carl Moreschi N4PY
> ----- Original Message -----
> From: "Duane Grotophorst" <n9dg at yahoo.com>
> To: <tentec at contesting.com>
> Sent: Friday, March 07, 2003 2:59 PM
> Subject: Re: [TenTec] Orion 9 MHz filters
>
>
> >
> > Or to put it another way they are at the beginning of
> > the IF chain, not distributed throughout or just
> > before the detector stage.
> >
> > The purpose and function of the crystal filters in the
> > Orion are somewhat different than its non DSP-IF
> > predecessors. They are not intended to establish the
> > final IF selectivity at all, but are instead intended
> > to limit the amount of signal spectrum energy (which
> > also includes both unwanted signals and broadband
> > noise) that reach the later mixer stages and A to D /
> > DSP stages.
> >
> > As such I would not get too wrapped up now trying to
> > decide which additional filter to add (if any) until
> > you have put the Orion through it paces for awhile. If
> > you do a lot of CW work with strong signals less than
> > few hundred Hz away then one of the narrower filters
> > may help you, if not they will add little value. Also
> > remember that all of the other DSP IF amateur radios
> > out there (that I know of) have 15-20 KHz filters
> > which are equivalent in purpose to the 9MHz filters in
> > the Orion.
> >
> > I would also be cautious of any third party filters
> > that may be prone to ringing, they could conceivably
> > hurt RX performance because the DSP IF stage will have
> > to deal with both the existing desired signal + noise
> > and the filter "added" ringing signal. So for the 9MHz
> > filtering in the Orion I would lean toward not buying
> > any optional 9MHz filters to begin with, but instead
> > wait and see how well it plays without them first, and
> > then decide.
> >
> > Duane
> > N9DG
> >
> > --- N4PY <n4py at qvssoftware.com> wrote:
> > > The Orion Crystal filters are roofing filters and
> > > not IF filters.  The PBT
> > > will adjust the DSP IF filters.  The DSP filters
> > > will lie entirely inside
> > > the roofing filter passband.
> > >
> > >
> > > Carl Moreschi  N4PY
> > >
> > > ----- Original Message -----
> > > From: "Mark Erbaugh" <mark at microenh.com>
> > > To: <tentec at contesting.com>
> > > Sent: Friday, March 07, 2003 12:47 PM
> > > Subject: [TenTec] Orion 9 MHz filters
> > >
> > >
> > > > As I was replying to someone about the 9 MHz
> > > filters in the Orion, a
> > > > question occured.  On the Omni V and VI, the 9 MHz
> > > filters are not
> > > tuneable.
> > > > The passband is fixed. Only the 6.4 MHz filters
> > > are tunable via the PBT
> > > > control. Are / will the 9 MHz filters in the Orion
> > > have a PBT adjustment?
> > > >
> > > > 73,
> > > > Mark
> >
> >
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