Ipo (Intercept Point Optimization) - Yaesu FTDX9000D Operation Manual

Normally, the front-end FET RF amplifiers provide maximum sensitivity for weak signals. During typical conditions on lower frequen-
cies (where strong signals and high noise are common), the RF amplifiers can be bypassed by pressing the IPO button so that the
button's illumination is lit. This improves the IMD (intermodulation distortion) rejection characteristics of the receiver, with only a
slight reduction of sensitivity. On frequencies below about 10 MHz, you generally will want to keep the IPO button engaged at all times,
as the preamplifiers are usually not needed at these frequencies unless you are using a Beverage or other lossy receive antenna.
Quick Note
The FT 9000's first mixer is an active type, using four SST310 Junction FETs. This mixer design provides gain to the
DX
receiver chain, so the noise figure of the receiver is fundamentally lower than with some other designs. Therefore, it frequently
is not necessary to utilize the RF preamplifier, and the receiver Intercept Point will be substantially increased by engaging IPO,
so as to feed the incoming signals directly to the first (active) mixer. We recommend that IPO be switched on whenever possible.
Main (VFO-A) IPO Setup
Press the Main (VFO-A) side's
to engage the IPO on the Main (VFO-A) band.
A Red LED imbedded in the switch will light up, and the
preamplifier for the Main (VFO-A) receiver will be by-
passed. The system gain and sensitivity will be reduced.
To cancel IPO operation and restore full system gian and
sensitivity, press the
SUB(VFO-B) IPO Setup
Press the Sub (VFO-B) side's
engage the IPO on the Sub (VFO-B) band.
An Orange LED imbedded in the switch will light up, and
the preamplifier for the Sub (VFO-B) receiver will be by-
passed. The system gain and sensitivity will be reduced.
To cancel IPO operation and restore full system gain and
sensitivity, press the
FT 9000D O
DX PERATION
IPO (I
NTERCEPT
-IPO switch key
-IPO switch key once more.
-IPO switch key to
-IPO switch key once more.
M
ANUAL
C
ONVENIENT
P O
OINT PTIMIZATION
MAIN(VFO-A)
-IPO switch
SUB(VFO-B)
-IPO switch
F
EATURES
)
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