[TenTec] Orion Roofing Filters

[Mark Erbaugh]

Bill,

> By the way Mark, did you enable your 250 Hz filter?  Perhaps that
> was causing the problem you are having.

Yes, the 250 Hz filter was enabled. When I disable it in the menu, the
performance doesn't change between 500 Hz and 250 Hz as expected as the
Orion keeps the 500 Hz filter enabled if it doesn't have or thinks it
doesn't have a 250 Hz filter.

I've done some further testing, this time using my Elecraft XG-1 (mini
signal generator).

The XG-1 can generate a 1 or 50 uV signal at about 7.241 Mhz.

Orion setup:

Mode: LCW
Roofing filter: Manual
DSP filter: 6 kHz
Preamp: On
AGC: Slow (Hang: 0; Decay 20 dB / Sec; Threshold 0.37 uV)


XG-1 signal zero beat at the 700 Hz CW side tone frequency using the MixW
spectrum display. The S-Meter readings for the 250 and 500 Hz filters were
peaked by adjusting the center frequency adjustment. Note: that centering
the 250 Hz filter did have a noticeable effect on the S-Meter reading, so it
must be doing something and it did peak so the peak wasn't out of range.

The table below shows the Orion's S-Meter reading  ( 12 / 9 = 12 dB over
S9 )

Roofing Filter    no signal    1 uV    50 uV
250                   1.2            1.8      7.8
500                   1.3            4.3      12 / 9
1000                 1.2            3.8      10 / 9
1800                 1.2            3.5      7 / 9
2400                 1.3            4.0      11 / 9
6000                 1.8            4.0      11 / 9
20000               1.9            4.0      10 / 9




Mark