FCC ID: K66FT-857
Operating Manual
Vertex Standard Co., Ltd.
43
50 MHz operation) make the setting “ATAS (HF).”
3. Press and hold in the [F] key for one second to save the new setting and exit to normal operation.
Automatic Tuning
1. Press the [F] key, as needed, to recall Multi Function Row “k” [TUNE, DOWN, UP].
2. Press the [A](TUNE) key to turn the ATAS-100/-120 on (this action only supplies voltage to the antenna at this point;
re-tuning does not begin). “Parentheses” will appear on the both sides of the “TUNE” indication, and the “ATAS” will
appear on the LCD.
3. Now press and hold in the [A](TUNE) key for one second to initiate ATAS-100/-120 tuning. The transmitter will
automatically be activated, a carrier will be sent, and the antenna’s length will be adjusted for best SWR.
4. If the microprocessor determines that the antenna’s length is radically incorrect from the optimum value, no carrier
will be sent out. Instead, in the receive mode, the antenna will retract to its shortest position (this may take up to one
minute). While this is happening, do not press the [A](TUNE) key again.
When the ATAS-100/-120 reaches its minimum length, automatic tuning will be initiated, and the
transmitter will automatically shut off when a satisfactory SWR is achieved.
5. On the 144 MHz and 430 MHz bands, the ATAS-100/-120 does not require a tuning process. SWR will be
satisfactory when the antenna is fully retracted.
6. When you wish to conclude ATAS-100/-120 operation, press the [A](TUNE) key; the “Parentheses” disappear
surrounding the “ATAS” indication.
Manual Tuning
In some instances, the SWR may be slightly improved by manual adjustment of the antenna position. This may be needed
for operation on bands like 40 meters, where the “Q” of the ATAS-100/-120 is high, causing a narrow resonance range.
Before Manual Tuning, press the [F] key, as needed, to recall Multi Function Row “i” [MTR, -----, DISP], then press the
[A](MTR) or [B] key to change the meter function to the SWR meter (“SWR” icon will appear at the upper of the [B]
key).
To tune the ATAS-100/-120 manually, recall Multi Function Row “k” [TUNE, DOWN, UP], then press and hold in the
microphone PTT switch. With the transceiver in the “transmit” mode, press and hold in the [C](UP) key (to raise the
antenna) or the [B](DOWN) key (to lower the antenna). While you hold in one of these keys, the FT-857 will generate a
carrier, and you may watch the top scale of the FT-857’s meter, looking for the meter indication to reach its minimum
value. When this is reached, release the [C](UP) or [B](DOWN) key, then release the PTT key to return to the “receive”
mode.
1) Once automatic matching has been successfully accomplished, you must change frequency by at least 10 kHz before
attempting automatic matching again. Within a window of ±10 kHz from a match point, the transceiver’s
