Ten-Tec ORION II, Руководство пользователя

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566 manual Version 4 – October 2006
Part #74410
Printed in USA
47
with hang at zero and RFGAIN backed down
to limit extraneous noise.
Consider the settings we have suggested for
single signal DXing: wider roofing filter, NR
(if desired) at a start value of “3” or higher,
use of programmable AGC, DSP bandpass
filter set at any value desired. Now
consider what we started with above:
conventional settings on a past transceiver
of 250 Hz crystal filter, AGC fast or off, DSP
NR on. Let’s say on Orion, you’ve put in
the 300 Hz roofing filter, put the DSP BW at
100 Hz, turned the AGC to fast or off, put
the DSP NR on “1”, and then went to copy a
single weak CW signal on the low bands.
Knowing what you now know, what is the
likely result? Not much chance that desired
signal is going to be as copyable (or
copyable at all!) as it would be with setting
the transceiver to take it to its full
capabilities.
To summarize for weak signal, single-
signal DXing:
Use the programmable
AGC settings, adjusting if needed for each
situation to enhance weak signal copy. Use
the narrow roofing filters only if a loud signal
is close enough to warrant it. Gain does not
vary for DSP bandpass filters – use any
value down to 100 Hz you feel comfortable
with. For weak CW signals, either leave NR
off or start NR at a setting of “3” or “4” for
quicker adaptation. Make sure the narrow
roofing filters, if you choose to use them, are
centered using the C.F. controls in the
menu
. Make sure the signal you are
listening to is zero beat at the CW offset
you have selected.
Contest operation is a little different.
Generally, contesters will not want to be
fiddling with controls during the course of the
contest like DSP NR, AGC, etc. unless it’s to
quickly adjust some parameter for a given
situation. The needs of the contester are
somewhat different from the single signal
DXer. The contester needs the radio to be
set for a somewhat optimum set of values to
meet these criterion: 1) the ability to copy
both weak signals and loud signals with
AGC good enough to minimize the output
variability between the two. 2) The
minimization of loud nearby signals having
an effect on overall receiver performance
and 3) having an reasonably optimum “start”
setting that will keep the operator from
having to constantly adjust controls on the
radio.
Now, these goals are not common to single
signal DXing.
At first thought, it would
seem that what would be good for single
signal weak signal DXing would also hold
true for contesting
– and perhaps for
previous transceivers there was an element
of truth to that. Actually, though, what
would be good for copying a varying ratio of
signal strengths under crowded band
conditions is not at all the same as copying
one weak signal with a Beverage receive
antenna under quiet (non-contest)
conditions.
Recommended start settings for CW
contesting: In the filter menu, set
Xtal Filter
to AUTO. This will bring in the desired
mode-appropriate roofing filter automatically
as you adjust the DSP BW filter settings
across the value of the roofing filter. Likely
loud signals are going to be present nearby,
and minimizing them as a factor in overall
receiver performance is paramount. This is
where
every other radio fails under contest
conditions. That S9+30 dB CQer 3 kHz up
the band from you? It’s
killing the receiver
performance of other radios, even though
the operator doesn’t hear the signal through
the
bandwidth filter. With the narrow
roofing filter, the ORION II has no negative
reaction to the same signal – preserving
receiver performance down to the smallest
bandwidths needed for optimal contest
operation.
Programmable AGC can also be of
tremendous value as it gives the operator
the ability to determine
in their head what
large signal strengths can be
accommodated. It also will prevent fast
AGC action from chopping up weak signals
present in the passband, which can happen
with conventional AGC settings.
Setting programmable AGC value is a little
more tricky for contest operation. Obviously,
you want a good amount of gain through the
system, but limit the ability of strong signals
to “blast the operator” in between listening to
the weak ones. Setting the AGC hang value
again to 0.00 or 0.04, a good starting point
for threshold value would be approximately
1 uV with decay at a somewhat slow value
to prevent signal clipping of the weak ones
as noted in the weak signal DXing