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Old March 25th 10, 11:44 PM posted to rec.radio.amateur.boatanchors
Antonio Vernucci Antonio Vernucci is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 395
Default Advice from SX-115 owners


Hi, Tony

I also realigned my SX-115. Results were excellent on cw and SSB
bandwidths, but the a.m. wide response was disappointing.
There was some very noticeable sensitivity loss in a.m. wide,
but I don't remember it being so much (maybe 1 S/unit).
My receiver is in storage, so I can't check easily.
I thought my problem was the T-notch filter still being
within the a.m. bandwidth. There is no on/off switch for the T-notch,
you just shift it away from where you are listening when not in use.

73,
Ed Knobloch


Ed,

yes, paying more attention I realized that, in the 5kHz position, bandwidth is
actually nearly twice the bandwidth in the 3 kHz position, but .... there is a
notch just in the middle, despite the notch knob is positioned at OFF (I know
that notch cannot be excluded, but just moved in frequency... ).

The consequence was that, at 5 kHz selectivity, I experienced the very strange
effect to hear the same AM station at two distinct frequencies, a few kHz apart
from each other.

But then, moving the notch knob, such "doubling" effect disappeared and I could
hear the AM station just at a single frequency, though with a much higher
bandwidth.

In conclusion, I had to put the notch knob at the other extreme with respect to
the OFF position, and the problem seems to no longer exist.

Thanks & 73

Tony I0JX

BTW: yes, the signal drop is closer to one S units than to two