[TenTec] Additional Thoughts on New Orion

[Bernard(wtrone)]

    Bill: your post was not confusing at all!  I really appreciate you
taking the time to explain some of these features and how they work.  Matter
of fact, I am printing this post, right now, for future reference.

    I keep a folder with all the interesting Orion posts.  That way, I don't
have to look for them and then wonder where I saw them.  LOL!!!

        73


        Bernard, WA4OEJ


----- Original Message ----- 
From: "Bill Tippett" <btippett at alum.mit.edu>
To: <tentec at contesting.com>
Sent: Tuesday, April 27, 2004 5:21 PM
Subject: [TenTec] Additional Thoughts on New Orion


> WA4OEJ wrote:
>
>  >I really have to wonder why they selected 6 kHz for the second filter
>
>          For AM users who want to reject adjacent channel IMD.
>
>  >and 2.4 kHz for the third filter.
>
>          For SSB users who want to reject the same.
>
>  >I find it difficult to copy a SSB signal with a bandwidth of less than
> 2.0 kHz.
>
>          Try setting PBT to +150 to +200.  That allows me to copy
> reasonably well down to ~1600 Hz BW (contest conditions).
>
>  >In the Orion auto filter selection position, my 2.4 filter doesn't kick
> in until the bandwidth is around 1.9kHz.  That's just too narrow for me.
>
>          It actually activates at ~2000 Hz.  This brings up another
> point.  If you use the optional 1800 Hz filter, "Auto" only activates
> it at ~1400 Hz which is definitely too low.  The only time I really
> use my 1800 is in contests, and I simply "lock" the 1800 in at all
> times.  The 1800's actual 6 dB bandwidth is closer to 1900 Hz, and
> it works fine for the 1600-2000 Hz range IF you set PBT as mentioned
> above.
>
>  >Other than the obvious reason of having compatibility with their other
> rigs, why wouldn't they have selected something like 7 or 8 kHz for the
> second filter and then something like 3.5 kHz  for the third filter?
>
>          Again Ten-Tec's logic was probably to choose roofing filters
> that would allow normal AM and SSB bandwidths.
>
>  >Second question, in the auto mode, how is the change over filter
> selected.  In other words, if I put a 2.8 kHz filter in place of the 2.4
> kHz, at what bandwidth would it be enabled?
>
>          In auto mode, the filters are switched when DSP BW is
> set to approximately 75% of the roofing filter's nominal
> bandwidth.  The transition points are as follows:
>
> Filter  Switches @
> 6000            4500
> 2400            2000
> 1800            1400
> 1000            750
> 500             380
> 250             190
>
> You could move or substitute filters in different
> positions but they would still switch at the above
> fixed setpoints in Auto mode.
>
> CAUTION #1:
>
> Orion transmits through these filters also, and I
> believe 2400 Hz is used in CW and 6000 Hz is used
> in SSB.  You should probably NOT put anything but
> standard filters in these two slots.  Possibly
> slightly wider filters such as the 2800 would be
> OK in the 2400 slot but I would NOT recommend
> narrower filtes in these two slots.  There is not
> a problem for the other positions.  For example,
> I have my 1000 in the 1800 slot now and the Inrad
> #352 600 Hz in the 1000 slot.  This works fine in
> Auto with the 1000 switching in at 1400 Hz and the
> 600 switching in at 750 Hz.
>
> CAUTION #2:
>
> Standard 500 Hz and 250 Hz Ten-Tec or Inrad filters
> will NOT work in the 1000 Hz and higher slots.  The
> reason is that the 500/250 slots assume an IF of
> 9.00075 and the 1000+ slots assume an IF of 9.0015.
> Therefore, the 500/250 filters will NOT center properly
> if inserted into the 1000 or higher slots.
>
>          Hope I didn't totally confuse you!
>
>                                          73,  Bill  W4ZV
>
> P.S.  It is of course always possible to override
> any of the Auto settings by simply fixing the filter
> of your choice in Menu > Filter.
>
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