Hi again Jack,
Another possibility, I should have mentioned in my first post, is that
you may not have the PBT set so that the NAR 9MHz 217 filter bandpass is
coincident with the 6.3 MHz bandpass. Switch to the 2.4 kHz BW filter
in the 6.3 MHz IF, and adjust the PBT for maximum audio noise output.
Then switch to 1.8 kHz and adjust PBT again for maximum noise. Repeat at
500 Hz and 250 Hz (if you have them all).
If you are accustomed to the way most JA rigs with PBT work, you may
think the Omni VI is broken. With most JA rigs the narrowest filter,
before the IF that gets shifted by the passband tuning, is about 15 kHz
BW. Any setting of the PBT just moves the passband and thus audio pitch
you hear, while it is always well inside the 15 kHz filter of the 1st
IF. With the Omni VI when you adjust the PBT, the 6.3 MHz 2nd IF
bandpass can be set outside of the bandpass of the 9MHz 1st IF. The
default 9MHz BW is 2.4 kHz, much narrower than the typical JA rig. And
when you put the 217 in and select NAR, your 1st IF is 500 Hz BW and if
you don't get the 2nd IF bandpass coincident with it, you have great
attenuation. It may seem like the rig is broken, when really you just
haven't yet understood how to use it.
The feature of moving the 2nd IF passband around over a larger 1st IF
bandwidth that a lot of JA rigs have, is something I sort of miss.
However the performance gained in losing that flexibility is worth it,
and I wouldn't go back.
DE N6KB
Jack Wigal wrote:
I recently purchased an Omni-6 and later added a #217 500hz filter to the 9
mhz IF. With the amplifier jumped in I'm getting about two S-units of
attenuation and with no amp I'm getting about three S-units of attenuation.
I'm sure this isn't normal, so does anyone have any suggestions?
Thanks, Jack kr8z
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