23
Receiver Accessories
Noise Blanker
The IF Noise Blanker may be useful in reducing or eliminating some types of impulse
noise, especially noise generated by automotive ignition systems.
1. Press the key momentarily, then rotate the
knob, as needed, until Operating
Function Row 8 [NB, AGC] appears on the display.
2. Press the
(NB) key to activate the Noise Blanker. The “
” icon will appear at the
right of the “NB” indication.
3. Press the
(NB) key again to turn the Noise Blanker off.
IPO
(
Intercept Point Optimization
)
The IPO feature bypasses the receiver RF preamplifier, thereby eliminating the preamp’s
gain. This feature is not available on the 144 MHz and 430 MHz.
1. Press the key momentarily, then rotate the
knob, as needed, until Operating
Function Row 7 [IPO, ATT, NAR] appears on the display.
2. Press the
(IPO) key to bypass the receiver input preamplifier. The “
” icon will ap-
pear at the right of the “IPO” indication.
3. Press the
(IPO) key once more to re-activate the preamp.
On the bands below 14 MHz, the input preamplifier is rarely necessary, and activa
-
tion of the IPO feature will provide substantial protection against intermodulation
and other problems associated with strong signal input to the receiver. Rule of
thumb: so long as the S-meter is moving on background noise, additional front-end
gain is not necessary.
ATT
(
Front End Attenuator
)
The Attenuator will reduce all signals (and noise) by 10 dB, and it may be used to make
reception more pleasant under extremely noisy conditions. This feature is not available on
the 144 MHz and 430 MHz.
1. Press the key momentarily, then rotate the
knob, as needed, until Operating
Function Row 7 [IPO, ATT, NAR] appears on the display.
2. Press the
(ATT) key to activate the Attenuator. The “
” icon will appear at the right
of the “ATT” indication.
3. Press the
(ATT) key once more to switch the Attenuator out of the receiver front
end circuit.
