FCC ID: K66FT-857
Operating Manual
Vertex Standard Co., Ltd.
11
Be sure to configure your amplifier so that it switches via a closure to ground, as provided by your FT-857. Alternatively,
many of these amplifiers use “RF Sensing” to control their relays; if yours is not in this category, you may then use the
T/R control line from the ring of the ACC jack for control of your HF linear amplifier, if desired.
The T/R control line is a transistor “Open collector” circuit, capable of handling positive amplifier relay coil voltages of
up to +50V DC and current of up to 400 mA. If you plan on using multiple linear amplifiers for different bands, you must
provide external band-switching of the “Lin Tx” relay control line from the “ring” connection of the ACC jack.
Important Note!
Do not exceed the maximum voltage or current ratings for the ACC jack. This jack is not compatible with negative DC
voltages, nor AC voltages of any magnitude.
Most amplifier control relay systems require only low DC voltage/current switching capability (typically, +12V DC at 25
~ 75 mA), and the switching transistor in the FT-857 will easily accommodate such amplifiers.
CW Key/Keyer Connections
All commonly-available keyer paddles should work perfectly with the built-in Electronic Keyer. The wiring configuration
for the paddle is shown below.
For straight-key operation, only the tip and shaft connections are used.
Note:
Even when using a straight key, you must use a three-conductor (“stereo”) plug. If a two-conductor plug is used,
the key line will be constantly shorted to ground.
When using an external electronic keyer, be absolutely certain that it is configured for “positive” keying, not “negative”
or “grid block” keying. The “key-up” voltage of the FT-857 is +5V, and the “key-down” current is only about 1 mA.
For CW automated keying using a personal computer, with an external memory keyer providing for manual sending, it
usually is possible to connect the keyed lines together via a “Y” connector. Check with the documentation accompanying
your keyer and your contest/DX software for any cautions which need to be observed.
Receiver Accessories (Tape Recorder etc.)
Connection of a tape recorder or other such receiver accessory is easily accomplished by using the DATA jack’s Data Out
(1200 bps) terminal (Pin 5) and Ground (Pin 2). The audio output is fixed at 100 mV, with an impedance of 600
Ω
.
Adjusting the Front Feet
The two front feet of the transceiver allow the transceiver to be tilted upward for better viewing. Simply fold both feet
forward to raise the front of the transceiver, and fold them back against the bottom case to lower the front of the FT-857.
Front Panel Control & Switches
1. Liquid Crystal Display
