I will tell you what I know about Omni VI IF filter possibilities.
All Omni VI versions have a 15 kHz BW 2 pole crystal filter as the 1st
filter in the 9 MHz IF. This filter is in the receive signal path at all
times for all modes.
The next filter in the Omni VI is a 2.4 kHz BW 8 pole crystal filter,
also in the 9 MHz IF. It is always in both the TX and RX signal path for
all modes except FM.
The third filter in an Omni VI is also in the 9 MHz IF. It is only in
the RX signal path, and it can be switched in or out. It is controlled
by the NAR button in options 1 and 2. In option 3 Omni VI and in the
Omni VI + there is space for two narrow optional filters in the 9 MHz
IF, and they are controlled by the N-1 and N-2 buttons. You can use one
or the other, or neither, but not both cascaded. When you select one of
these filters it is cascaded with the 2.4 kHz 8 pole filter and the 15
kHz 2 pole filter mentioned above. The 9 MHz IF option filter(s) can be
used in any mode except FM. They are only in the RX signal path not TX.
The next filters in the Omni VI are on the Pass Band Tuning board. This
is the 6.3 MHz IF. One of four filters on this board can be selected
using the 2.4, 1.8, 500 and 250 buttons on a version 1 or 2 Omni VI. On
a version 3 or + Omni VI there is no 2.4 button. You are using the 2.4
(stock standard) filter whenever you don't have 1.8, 500 or 250
selected. You always use one and only one at a time, they are not
Since you operate so much SSB, you will probably want either the 218 1.8
kHz filter as your narrow 9 MHz option filter, or perhaps the 220 2.4
kHz or one of Inrad's filters. Or you may find that you like CW much
more with the Omni VI than you ever have before. There is still hope for
you. You may decide on the 217 500 Hz filter instead. With a version 1
or 2, you only have one 9 MHz option filter space.
It is my understanding that the only stock filters in the Omni VI are
the 15 kHz 2 pole and the 2.4 kHz 8 pole in the 9 MHz IF, and the 2.4
kHz filter in the 6.3 Mhz IF. This leaves you one slot to fill in the 9
MHz IF in a version 1 or 2, and two 9 MHz slots to fill in a version 3
or +. In all versions there are 3 slots open in the 6.3 MHz IF, assuming
only the 2.4 kHz stock filter is installed.
I am sure you will love the Omni VI. It is a great radio.
73 DE N6KB
> I had a question about the filters. I gather the rig came with a stock
>cw filter and also a ssb filter? are these both in the first if? I
>understand you can put a total of 3 more
> filters in... 1 in the first if and 2 in the second if. I do about 20%
>cw if that ,the rest is ssb and a little digital. could someone give me
>a overview on the VI's filter system and a
> a opinion for filters ,per the way I described my operating .
TenTec mailing list