Yaesu FTDX9000D Operation Manual

Also see for FTDX-9000D: Operation manual Brochure & specs Update guide Update guide Update guide

Contents

Page 61FTDX9000D OPERATION MANUALIPO (I NTERCEPT P OINT O PTIMIZATION )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 thebutton's illumination is lit. This improves the IMD (intermodulation distortion) rejection characteristics of the receiver, with only aslight 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 NoteThe FT DX 9000’s first mixer is an active type, using four SST310 Junction FETs. This mixer design provides gain to thereceiver chain, so the noise figure of the receiver is fundamentally lower than with some other designs. Therefore, it frequentlyis 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 SetupPress the Main (VFO-A) side’s -IPO switch keyto engage the IPO on the Main (VFO-A) band.A Red LED imbedded in the switch will light up, and thepreamplifier 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 andsensitivity, press the -IPO switch key once more.SUB(VFO-B) IPO SetupPress the Sub (VFO-B) side’s -IPO switch key toengage the IPO on the Sub (VFO-B) band.An Orange LED imbedded in the switch will light up, andthe 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 andsensitivity, press the -IPO switch key once more.SUB(VFO-B)-IPO switchMAIN(VFO-A)-IPO switchCONVENIENT F EATURES