Noise Blanker - Kenwood TS-940S Instruction Manual

• ®NOTCH control
Use this control when you are experiencing interference
from a CW Heterodyne type signal. Turn the NOTCH ON
and slowly adjust the NOTCH control to minimize the beat
signal. A beat of approximately 1.5 kHz can be reduced at
the approximate center position of the control. Please
note that this control will not eliminate SSB, AM or FM
type interference. The bandwidth of such signals is ap-
proximately 3 - 6 kHz wide. When in the USB, CW or AM
mode a beat tone lower than the center frequency can be
reduced by rotating the control clockwise from the center
point. In LSB or FSK mode adjust the control counter-
clockwise.
5-8. NOISE BLANKER
• @
NB 1 switch®
For pulse type noise, such as generated by automotive ig-
nition systems, turn the NB 1 switch ON. Adjusting the NB
LEVEL control varies the blanker's threshold, eliminating
even low level noises.
NOTE:------------------~-----------­
If high level receiver levels are present on an adjacent fre-
quency, do not use excessive NB threshold LEVEL as it
may cause receiver distortion. If you are operating near
other strong signals, use the RF A TT along with the noise
blanker level control.
• ®
NB2 switch ®
Noise blanker 2 is used for long duration pulse noise, like
the "Russian Woodpecker".
Unfortunately no noise blanker can remove all different
types of interference, but the two noise blankers that have
been provided in the TS-940S are effective in most cases.
e
@ NB LEVEL control®
Controls the noise blanker operating level. Use only the
minimum level necessary.
22
nB
dB
I fO-ri +2kHZ
1 fa • I ,
~
2 kHz
BFO
BFO
NOTCH
-@-SQL
NOTCH
-@-SOL
4 6 4 6
2
8
2
8
0 0
Notch off
Notch on
NOTCH operation (LSB mode)
NBl
NB2
D
I I
NB LEVEL
I
2
8
0
10