FTdx Series History
The FTdx series of transceivers began with the FTdx400 in 1968. It was rated at 500 watts pep input on SSB. I believe this transceiver was reviewed in QST in 1968. The FTdx560 and 570 appeared around 1970. These were both 560 watt rigs with the 570 being a deluxe version with built in speaker and cooling fan. The FTdx401 came out around 1971-1972 and was essentially the same radio with a few more transistors and the capability to transmit in the AM mode. The FTdx 401B was the last of the series and appeared around 1973 and was probably the most refined of all. The features were the same as the others but with a few more bells and whistles. All of these radios featured 100 khz and 25 khz calibrators which were great for analog tuning. They all featured a R.I.T. control which allowed you to tune the receiver a few kc's independent of the transmitters frequency. One unusual feature is the backward reading S meter. It reads from right to left on incoming signal strength and ALC. It reads left to right for cathode current and power output. Its a little hard to get used to until you use the rig for a while. Check out the close up picture of the FTdx560 S meter. They all share the same basic layout and tubes and all feature a built in power supply. These were very advanced radios for their time. They are still competitive by todays standards. With an output of around 200-250 watts they put out an impressive signal.
The Yaesu FTdx560 is a 20 tube transceiver with the exception of 4 transistors used in the vfo and crystal calibrator circuits. The ac power supply is also built in and not seperate like some of the early transceivers making it a favorite for portable and field day operations. It is rated at 560 watts input on SSB and 500 watts on C.W. It uses two 6KD6's as the final amplifiers. The bands covered are 80 through 10 meters (no warc bands) as well as WWV and two aux positions which could be used for CB or addition of a warc band. The rig features 100khz and 25khz calibrators as well as R.I.T. and the capability to use an external vfo (FV400) for crossband operation. These transceivers were manufactured in Japan in the early 1970's and sold in this country by Spectronics.
The Yaesu FTdx570 is basically the same radio as the FTdx560 but with built in speaker and a cooling fan. These radios typically sold for about 100 dollars more than the FTdx560.
The Yaesu FTdx400 was the first in the FTdx series, being introduced to American hams around 1968. It was a 500 watt rig that would transmit in the a.m. mode as well as SSB and CW. This was also a massive radio weighing around 45 pounds with 20 tubes.
Here are some links I hope you might
BARC Swap Shop
Hallicrafters Collectors Association
Ham Radio Gear Hampedia
Yaesu on Ebay
Antique Electronics Supply On Line