[TenTec] ORION Hi/Lo Cut control

[Grant Youngman]

We must have different radios :-)

Hi cut (independent of the selected sideband) alters the high 
frequency component of the passband while leaving the low 
frequency edge fixed.  Low cut (also independent of sideband) 
moves the low frequency (correct relative to sideband) edge and 
leaves the high frequency edge fixed in place.

I do seem to recall that there was an email from Scott that indicated 
that the NUMERIC value for PBT was not properly updated if the 
HIGH cut control was used with a PBT offset.  I'd have to go back 
and look through the archive.  May not be right on this, might have it 
backwards.  Don't really pay any attention to the numbers anyway.

Graphically, the results look exactly as would be expected to me.

With LO cut, the graphical representation appears to be correct.  
The skirt farthest from the carrier (the screen picture, at least) 
bobbles a bit, but remains essentially fixed, while the edge closest 
to the carrier moves as expected.

Grant/NQ5T



> I realise this topic has been aired previously but I am not sure it
> was satisfactorily concluded and I am not one who will readily let
> sleeping dogs lie!
> 
> For the most part I use the BW/PBT controls on my Orion.  They 
operate
> both logically and correctly, so far as I can tell.  On the other
> hand, I find operation of the Hi/Lo cut controls to be neither logical
> nor correct.
> 
> I have the following obsevations concerning operation of hi/lo cut 
and
> will be interested to learn the views of other users..
> 
> 1.  Hi and Lo cut on the Orion refer to absolute frequency, which I
> suppose is technically correct but this has the effect of
> interchanging the audible effect of the controls when changing 
from
> USB to LSB.  I feel operation might be more logical or at least 
more
> intuitively correct if the terms referred instead to recovered AF
> frequencies.  In this way application of Hi cut would always reduce
> the HF part of the recovered bandwidth and likewise Lo cut would
> reduce the bass frequencies..
> 
> I made the following obsevations with the rig on USB.  As Hi and 
Lo
> currently relate to absolute frequency the senses would be 
reversed on
> LSB.
> 
> 2.  The graphical representation of Hi cut appears correct.  The 
skirt
> furthest from the carrier is adjusted whilst the skirt nearest the
> carrier remains anchored.  However, adjustment of Hi cut does 
not
> adjust actual i/f b/w, until the Hi/Lo cut control is pressed and held
> for a second or so.  This makes no sense.  Actual b/w adjustment
> should be immediate while pressing and holding the control 
should
> reasonably restore the pre-adjustment b/w.
> 
> 3.  The graphical representation of Lo cut is incorrect.  What 
should
> be seen, is movement of the filter skirt closest to the carrier while
> the skirt away from the carrier remains anchored.  The graphic 
shows
> both skirts being adjusted but at different rates.  This is not
> correct.  The numerical indication shows PBT shifting at twice the
> rate of b/w change.  This makes no sense.  What should 
reasonably
> happen would be for PBT to display a figure equal to the delta in 
b/w.
> The adjustment of the Lo cut control does however, adjust actual 
b/w
> immediately, unlike Hi cut and pressing and holding the control 
does
> restore the pre-adjustment b/w.
> 
> Incidentally, I have two Orions and my obsevations hold good for 
both
> of them.  They have also held good over a number of firmware 
releases,
> so this is not a new problem.
> 
> Whatsay?
> 
> 73 de Bob, 5B4AGN
> 
> 
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-------------------------------
Grant Youngman /NQ5T
http://www.globeking.com
nq5t at comcast.net < == NEW