ft-450at receiver circuit analysis and simplified block diagram
ft-450at receiver circuit analysis and simplified block diagram vs describes this radio as a real dx receiver! "the 67.899 mhz 4-pole roofing filter (mcf) and 8 band-pass filters at the rf stage provide excellent suppression of out-of-band interference". the receiver is dual conversion; the 1st if is 67.899 mhz. the 24 khz 2nd if is passed directly to the dsp circuit. after the 8-section bpf, the rf signal is fed, along with the lo, to the active dbm (doubly balanced) 1st mixer - either via the rf preamp (2 x 2sk520 jfet) or directly (ipo "on").
a single 4-pole mcf roofing filter, with 10 khz bandwidth and an optimum shape factor, follows the 1st mixer. the 1st if signal leaving the roofing filter passes via the 3sk151 1st if amplifier to an image-reject 2nd mixer which down-converts it to 24 khz in one step. the 24 khz 2nd if drives the dsp (an adi "blackfin" type adsp - bf531sbst).
the ft-450 should be available in italy at the end of june 2007, at a price of approx. 1000 euro (without at).
ft-450 - bottom view and top view - at version with atu-450 autotuner, and overall front view: news items and images offering a "sneak peek" always provoke a great deal interest on the various mailing-lists - especially when they are provided in anticipation of the technical and operational data accompanying ft-450 product release. these pages are intended not only to facilitate this, but also to allow potential owners to become acquainted with the architecture, basic design concepts and implementation of the ft-450 - and to compare it to other radios.
the radio appears solidly constructed, in a die-cast aluminum chassis, well laid-out and clean - without untidy internal cables and wiring. this compact rig has a new packaging design to attain that useful and much-sought-after "simplicity of operation" with all important functions easily accessible, in contrast to the multiple controls of previous models.
ft-450 - structural examination and components of transmitter pa unit and front display. the new, compact transceiver from vs/yaesu incorporates technology derived from the recently ft-2000 project. in effect, as can be seen clearly from the two juxtaposed pictures (below), the pa uses 2 mitsubishi rd100hhf1 mosfet's in push-pull, with vdd = 13.8v. the pa unit is built up on one pc board, which also comprises the transmit low-pass filters (lpf) with their bandswitching relays. the pa is similar to that employed in the well-known ft-2000.
the following relay types are utilized for bandswitching: 2 x ag201344 for 50 mhz and 12 x omron g5v-1 for the other (hf) bands. the other mosfets on the pa unit are 2 x rd16hhf1 (driver), and 1 x rd06hhf1 (pre-driver).
the backlit lcd display shows all data and graphical indications required for effective operator control of the radio. the generously-sized screen also features a chart, in block-diagram format, showing which controls and features are activated, including adjustment of the digital (dsp) if filter.
as in the ft-2000, bar-graph displays are provided for the contour, notch, dnr , width and shift controls, and for other indications.
ft450 - a new hf/50mhz transceiver from vertex-standard
as can be seen in the photo, the new ft-450 is built into a die-cast aluminium chassis, which encloses all the circuit modules. the atu-450 autotuner, covering all bands 160 to 6m, is located in the underside of the chassis. it is optional on the ft-450 and factory-fitted on the ft-450at version.
the pa employs 2 mitsubishi rd100hhf1 mosfets in push-pull, and delivers 100w. it is also designed for demanding operation such as contesting. the same power devices are used in the ft-2000.
as shown below, the ft-450 transceiver features a new if dsp circuit which utilizes an ic from the new analog devices blackfin dsp processor family. the adsp-bf531 sbstz400 is a new dsp ic which is similar to that employed in the new icom ic-7000 except for instrucion and data sram capacity (see table.)
product release of the new hf/50 mhz transceiver is expected early in may 2007. the ft-450 is an innovative radio for its price class; it is simple to operate and feature-rich. it incorporates a newly-designed if-dsp at the 24 khz 2nd if. in this radio, yaesu is using an adi blackfin adsp-531. it has a single receiver, but is fitted with a quick split function.
the ft-450 has if width, if shift, contour, digital nr and notch filter, which are adjustable via simple controls (as compared to the 9000 and 2000 series.) finally, we see a rig with few knobs, and can hope for optimum ergonomic efficiency. the radio features a large front-panel display which presents many functions and settings to the operator. the front-end roofing filter is a 10 khz bpf at the 67.899 mhz 1st if. this is an intermediate value, which should clean up the 1st mixer output and protect the 2nd mixer from strong out-of-band signals. [translator's note: the 2nd mixer, which down-converts 67.899 mhz to 24 khz in one step, is probably an i/q image-reject mixer similar to that found in the icom ic-7800.] among other features, a dedicated port is provided for the digital modes, as well as an internal autotuner (optional on the ft-450, standard on the ft-450at.)
re are some preliminary notes in anticipation of the imminent product launch of the new yaesu 100w hf/50 mhz transceiver. for now, a prototype picture is available. the radio is dual-conversion: 1st if 67.899mhz - 2nd if 24khz. if-dsp at the 24 khz if. the dsp ic has a 36.864 mhz clock frequency. din sockets for data/tuner, linear and cat are provided.
the fcc (usa) has already granted equipment certification (fcc id: k6620241x50.) note that as for other new-product announcements stating "device not approved", this d
