Orion 250 Hz & 500 Hz Filter Center Frequency Adjustment

From the Ten-Tec Reflector January 20, 2005

This is very simple requiring only a steady signal source (i.e. no noise sources, Spectrogram plots, etc.)

1. Tune and zero beat Orion to a steady signal source.
2. Set DSP = 1000 or higher to take any DSP filtering out of the adjustment. Enable and select desired filter in Filter Menu. Do NOT leave it in Auto.
3. With C.F. Adj highlighted and not touching VFO, adjust your Multi knob so that you see equal downward deflection on the S-meter on both sides of the carrier. I would suggest about 1 S-unit or 6 dB deflection, or whatever meter marking is closest to that (i.e. not critical as long as you make it the same deflection on both sides).
4. Write down the readings for each side of center. For example, you might have something like -60 and +20. Add these two numbers together and divide by 2 ([-60 +20] / 2 = -40/2 = -20). Set C.F. Adj. to that value. Your filter is now properly centered, independent of any passband ripple.
5. Now check your work by first noting VFO zero beat (A=B is a simple way to keep track), and tune VFO to both sides to the same meter mark you used in 3 above, noting both frequencies. If you've done it correctly, both should be at an equal offset from the zero beat frequency.

73, Bill W4ZV