OK Tommy, I will have to sift through all the very good info I have been
reading and make a decision about the filters being left in the Orion or
not. I suppose if they are left in I can always disengage them and just use
the 762, which is probably what I might do. I'll wait a few days and see if
anything else is uncovererd that could be of interest in this regard.
Thanks for the help!~ Toby W4CAK
----- Original Message -----
From: "Tommy" <aldermant@alltel.net>
To: <tentec@contesting.com>
Sent: Saturday, August 14, 2004 2:12 PM
Subject: Re: [TenTec] Inrad 762
> Sorry, I didn't read all you had said Toby.
>
> The 600Hz filter will give you advertise IMD performance at it's stated
> bandwidth, but not down to 100hz.. That was what the 500hz and 250 hz
> filters were supposed to do. But if you think about it, how many times are
> you going to actually work a S-9/60dB over signal, within 250hz or, for
> goodness sake, within 125 hz of your operating frequency? Even 300hz, for
> that matter. A 600hz filter (+/- 300hz from Fo) should actually be more
than
> adequate for all practical operating conditions. (my opinion)
>
> Tom
>
> ----- Original Message -----
> From: "Toby Pennington" <toby423@earthlink.net>
> To: <tentec@contesting.com>
> Sent: Saturday, August 14, 2004 1:49 PM
> Subject: Re: [TenTec] Inrad 762
>
>
> > Tommy, I thought the whole idea of the 600hz filter was to get better
IMD
> > from 750hz on down to 100 hz, so I wonder about you keeping the two
other
> > filters enabled. Have you tried just the 600hz with the 500 and 250 hz
> > filters disengaged. If so, what have you noticed. First I have heard
> about
> > the filter cover not being able to be tightened all the way down. Hope
> this
> > is not much of an issue. Toby W4CAK
> >
> > ----- Original Message -----
> > From: "Tommy" <aldermant@alltel.net>
> > To: <tentec@contesting.com>
> > Sent: Saturday, August 14, 2004 1:15 PM
> > Subject: Re: [TenTec] Inrad 762
> >
> >
> > > Tody,
> > >
> > > I concur with Bill's writting's. I didn't have the 1.8kc filter in my
> > Orion,
> > > so I moved the 1kc filter into the 1.8kc slot, put the 600hz filter
into
> > the
> > > 1kc slot, and left the 500hz and 250hz filters installed and enabled.
> > Really
> > > sounds quite impressive, especially in this CW contest going on this
> > > weekend.
> > >
> > > The Inrad filter is almost a half an inch taller than the TT filters,
> but
> > I
> > > did put the cover back over the filters, but just did not tighten it
> down
> > > fully. If I was going to keep my Orion, I would modify the filter
cover.
> > >
> > > Tom - W4BQF
> > >
> > > ----- Original Message -----
> > > From: "Bill Tippett" <btippett@alum.mit.edu>
> > > To: <tentec@contesting.com>
> > > Sent: Saturday, August 14, 2004 11:10 AM
> > > Subject: [TenTec] Inrad 762
> > >
> > >
> > > > Hi Toby,
> > > >
> > > > W4CAK wrote:
> > > > >Has anyone tried putting the New Inrad #762 in the 500hz slot of
the
> > > > Orion. Since the 1khz filter does an excellent job down to 380 hz,
> > would
> > > > this not be a better use of the 762?
> > > >
> > > > That won't work very well for several reasons:
> > > >
> > > > 1. The 500 slot always has the second amplifier engaged...thus it
> > > > should still be introducing IMD products.
> > > >
> > > > 2. The 4-pole Inrad 762 has less insertion loss than standard
8-pole
> > > > 500 Hz filters, aggravating the fact that the 500 position already
has
> > > > too much gain, even for the standard 500 Hz filters. TT used a
> > > > fixed 12 dB gain amplifier for both the 500/250 slots. That is a
> > > > good match for the 250's high insertion loss but too much for a 500.
> > > >
> > > > 3. The center frequency of the 762 is 9.001500 but Orion thinks
> > > > the 500 position has a 9.000750 Hz center frequency. Thus the
> > > > filter will not be correctly centered, although you can partially
> > > > compensate for this by using both C.F. Adjust and PBT. I think
> > > > it can be made to work for UCW but not LCW (could be the other way
> > > > around in the case you propose). If you compensate using PBT,
> > > > signals will disappear any time you switch to a different roofing
> > > > filter.
> > > >
> > > > I went through the same thinking when first looking into
this
> > > > filter issue, but I tried installing the 500 Hz filter into the
> > > > 1000 Hz position. That doesn't work well either for similar
reasons.
> > > >
> > > > Just plug your 762 into the 1000 Hz slot and everything
works
> > > fine.
> > > > If your 1800 slot is empty, put your 1000 there. If you already
have
> > > > an 1800, simply set your 1000 aside...you'll never miss it for
reasons
> > > > I've explained many times (1800 & 1000 being equivalent IMD fighters
> > > > down to 2 kHz spacings where the 762 will take over and is far
> > > > superior to either).
> > > >
> > > > 73, Bill W4ZV
> > > >
> > > >
> > > >
> > > > _______________________________________________
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> > > > http://lists.contesting.com/mailman/listinfo/tentec
> > >
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> > >
> >
> >
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