USING THE AUTOMATIC ANTENNA TUNER

The Automatic Antenna Tuner (hereinafter referred to as the “ATU”) built into each FT-2000is crafted to ensure a 50-Ohm load for the final amplifier stage of the transmitter. We recommend that the ATU be used whenever you operate on the FT-

2000.

ADVICE:

￿The ATU of the FT-2000, being located inside the station, only adjusts the impedance presented to the transceiver at the station end of your coaxial cable feedline. It does not “tune” the SWR at the antenna feedpoint itself. When designing and building your antenna system, we recommend that every effort be made to ensure a low SWR at the antenna feedpoint.

￿The ATU of the FT-2000includes 100 memories for tuning data. Eleven of these memories are allocated, one per Amateur band, so that each band has at least one setting preset for use on that band. The remaining 89 memories are reserved for the 89 most-recent tuning points, for quick frequency change without the need to retune the ATU.

￿The ATU in the FT-2000is designed to match impedances within the range of 16.5 Ohms to 150 Ohms, corresponding to an SWR of 3:1 or less on the HF amateur bands (6 m amateur band: 25 Ohms to 100 Ohms, corresponding to an SWR of 2:1 or less). Accordingly, simple non-resonant whip antennas, along with random-length wires and the “G5RV” antenna (on most bands) may not be within the impedance matching range of the ATU.

ATU OPERATION

1.Rotate the [RF PWR] knob fully clockwise (to the right).

2.Use the Main Tuning Dial knob to set the radio to the desired operating frequency within the Amateur band.

3.Press the [TUNE] button momentarily to place theATU in the transmit line (no adjustment/tuning will occur

yet). The “” icon will appear in the display.

QUICK POINT:

The momentary press of the [TUNE] button will turn the tuner on, and the microprocessor will automatically select the tuning point closest to the current operating frequency.

4.Press and hold in the [TUNE] button for two seconds to begin automatic tuning. The transmitter will be en-

gaged, and the “” icon will blink while tuning is in progress. When the optimum tuning point has been reached, the radio will return to receive, and the

“” icon will again glow steadily (instead of blinking).

5.While tuning around the band using the Main Tuning

Dial knob, you will observe that the “” icon blinks momentarily every 10 kHz. This momentary blinking indicates that a new tuning window has been entered. If you want to save tuning data associated with this 10 kHz window, repeat step 4 (above) for each such window. On bands like 1.8 MHz where the im- pedance may change rapidly, the storage of a number of tuning points is recommended.

6.To disconnect the ATU from the transmit line, press

the [TUNE] button momentarily. The “” icon will turn off, confirming that the ATU has been turned off. In the “Off” mode, the transceiver will be directly connected to the coaxial cable connected to your an- tenna, and will operate based on whatever impedance is present at the station end of the coax.

NOTCH Indicator

[DNR] Knob

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[DNR] Button

ADVICE:

The ATU circuit is located between the final amplifier and the rear-panel antenna jack; reception is not affected by the ATU.

QUICK POINT:

￿As shipped from the factory, only one ATU alignment point is saved on each Amateur band. This was memo- rized during the final alignment and performance veri- fication stages on the production line.

￿The momentary flickering of the “” icon occurs whenever you cross over into a new 10 kHz ATU memory window.

NOTE:

Please check the operating frequency before beginning the tuning process, to be sure you are not interfering with others who may already be using the frequency.

TERMINOLOGY:

Antenna Tuner Memories: The microprocessor of the ATU makes a note of the positions of the tuning capacitors and the selected inductors, and stores the data for each 10 kHz window in which tuning has occurred. This eliminates the need to re-tune every time you return to a frequency on which you already have completed the tuning process.

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FT-2000 OPERATING MANUAL