Do you have another filter you can put in that slot. If so, see how much
attenuation you get with the other filter. Then decide from the numbers
whether the fault seems to be the filter, or the switching circuitry and
amplifier associated with the filter slot. Lacking another filter, you
may be able to put a jumper in place of the filter, to determine if the
filter slot, switching diodes and amplifier are at fault. By the way,
whenever you select NAR filter, the additional amplifier Q4 is being
used. The jumper just determines whether attenuator R20, R21, R22 is in
line with the narrow filter and the amplifier. I'd say the most likely
points of failure are the switching diodes D8, D11, D12 and D14 and Q4
or the filter itself. Inspect the filter carefully for bad soldering,
easier to do than checking all the rest.
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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