Here are a few setup tricks I've enjoyed with my Orion:
          

Interfacing with Acom amplifiers
In order to avoid generating Arc Fault detection in the Acom amplifiers, it is suggested
that you install a Dunestar HPF-400 high pass filter in the coax line going from the Orion
antenna jack to the Acom amplifier.  Alternately, obtain a free hpf from Ten-Tec available
for this purpose.

SSB TX Settings
Increase mic gain until the ALC LED lights on voice peaks.  That's all there is to it.  
With my Heil HC5 headset cartridge, I only need a value of 7 but this will probably vary 
from mic to mic and rig to rig.  My monitor setting stays at 100 and more volume is 
obtained by increasing the subreceiver AF Gain, since the subreceiver acts as the monitor 
(and does a fine job of it).  For typical (non-hifi) use, I have TX EQ at -12dB (not critical), 
BW 2400hz, Rolloff 200Hz.  Speech Processor is usually set at 8.

SSB PTT wiring
If you connect a PTT switch to the front panel, be sure to wire it from mic jack pin 3 to 
the connector housing for ground.  DO NOT use the mic ground (pin 2) for PTT or you will 
introduce noise into your tx audio.  Alternately, use the rear panel Aux I/O cable.

CW TX Settings
To avoid key clicks, CW Rise/Fall should be set at 8-10 ms.  The actual risetime is about 
half of what the Orion menu displays.  On the air tests verify that clicks are transmitted 
if you go faster than 8 ms.

SSB RX
For the worst QRM condx (contest, etc), the Orion will go narrower and stay more readable 
than any rig I've ever used.  The trick is to dial in more + PBT as you go narrower as well
as negative values of RX EQ to accentuate high freq.  Typical setup for tough contesting
condx: 1450hz BW with 1.8Khz roofing filter, +330hz PBT, RX EQ -10dB  

CW Roofing Filter
Replace the stock 1000hz roofing filter with the Inrad 600hz roofing filter.  That's all 
the roofing filters you need for cw.  If you do install the narrower roofing filters 
(you really don't need them, even in the worst contest condx) then one trick to set the center 
freq adjustment in the Filter menu is to feed the Orion audio into a soundcard and use spectrum 
analysis software.  Set the dsp selectivity wide (2000hz) and manually select the xtal filter 
(Filter menu) and tune to band noise.  Ideally, the spectrum display will be centered on your 
cw sidetone freq (CW menu).  The offset in center freq is the value for the C.F. Adj menu setting.

CW RX
One technique I sometimes use when trying to bust a pileup is to carefully tune in the dx, 
turn DSP bandwith down to 100hz, and reduce RF Gain so dx is just audible above silent background.  
I can then listen more selectively for the dx rather than all the stations calling.

2nd RX Ant
I connect a 2nd Beverage to Ant 2 but make sure to turn on TX Keying Loop 2.  This will disable 
transmitting into Ant 2 (I hope) if there's no connection to TX EN 2.    

RF Gain (v1.372 and later)
After firmware release 1.372, some degree of AGC control was added to the RF Gain control. At 
that time, I adopted the technique of simply setting AGC Threshold to 1uV or less and adjusting
RF Gain just above the level I could first hear band noise.   

Sweep/NB/NR 
I never use these features and can't give any advice I'm afraid.