Kenwood AT-250 User Manual

loro
1H
AT-250
AUTOMATIC
ANTENNA
TUNER2=
CAUTION
1) The AT-250 is capable of sustaining 100W con-
2
FEATURES
1.
tinuous operating input power. However, during
auto tuning, very high voltage appears in the
tuning circuit and the reflected impedance for
the transceiver varies greatly. Therefore, to pro-
tect the transceiver, adjust the transmit output
to less than 50W before tuning.
The antenna tuner is capable of matching a 20—
150 ohm load, or approximately up to 2.5:1
SWR. If the antenna and feed system exceed this
range, the tuner may not stop, since it is beyond
the auto tuner’s capability. In this case, do not
attempt further auto-tuner operation.
To perform auto-tuner operation, first adjust the
antenna and feed system.
You are the owner of our latest product, the new AT-250 Automatic
Antenna Tuner. Please read this instruction manual carefully before
placing your unit in service. The unit has been carefully engneered
and manufactured to rigid quality standards, and should give you
satisfactory and dependable operation for many years.
3) The antenna tuner enables to reduce SWR of
high SWR antenna.
To transmit power efficiently, use the lower
SWR antenna correctly adjusted.
All amateur bands covered in the HF range
4. POWER-SWR meter
Covers all amateur bands including the new WARC band
from 1.8 through 28 MHz.
. Automatic band selection
When connected to the TS-430, the operating band is
automatically selected from the transceiver.
- Dual power source capability
Operation from either 120, 220, or 240 V AC or 13.8V
DC.
Up to either 20 W or 200 W is indicated by the 5u ilt-in
POWER-SWR meter. When the METER switch i; set to
SWR, SWR is autoamtically calculated and indiated on
the scale.
. Four antenna jacks
Four antennas cover a broad frequency range. Arty of
these antennas can be selected by the ANTENNA switch
on the front panel.
In normal operation (with the RX switch OUT), ml-y the
transmission signal will pass through the antenn ¢ uner.
AG SY
|

Kenwood AT-250 Specifications

Frequency and Impedance

frequency range	1.8 — 29.7 MHz
input impedance	50 ohms unbalanced
output impedance	20-150 ohms unbalanced

Power

pass through power	100W (200W PEP)
power consumption	15W AC
power requirement	120V, 220V, or 240V AC selectable

Dimensions and Weight

dimensions	W174 (174) x H96 (107) x D257 (289) mm
package dimensions	W385 x H167 x D264 mm
weight	4.2 kg (9.24 Ib.)

Summary

CAUTION

Operating Precautions

Cautions on power limits, impedance matching, and auto-tuning procedures to protect the transceiver.

FEATURES

HF Band Coverage and Auto Selection

Covers all amateur HF bands (1.8-28 MHz) and offers automatic band selection when connected to a TS-430.

Power and Metering

Supports dual power sources (AC/DC) and features a POWER-SWR meter indicating 20W or 200W and SWR.

Antenna Connectivity

Features four antenna jacks for flexible selection and broad frequency range coverage.

Connection with the TS-140/680

Connection Steps

Detailed steps for connecting the AT-250 to the TS-140/680 transceiver using supplied cables and power sources.

TS-140/680 Caution

Important caution regarding operating power and the 50 MHz band when using the AT-250 with the TS-140/680.

CONTROLS AND THEIR FUNCTIONS

Power Switch and Indicators

Description of the POWER switch, TUNER indicator, and TUNE indicator functions.

Tuning and Metering Controls

Explanation of the TUNE switch, POWER-SWR meter, and METER switch operations.

Band and Antenna Selection

Details on the BAND switch for frequency selection and the ANTENNA switch for selecting connected antennas.

Power Source and Connectivity

Information on DC/AC switch, ACC jack, AC power connector, DC power connector, and GND terminal.

CONNECTIONS AND OPERATIONS

Connection with TS-430

Instructions for connecting the AT-250 to the TS-430 transceiver, including ACC, INPUT, and GND terminals.

Connection with Other Transceivers

Guidance on connecting the AT-250 to transceivers other than TS-430, including TS-130, TS-530, TS-830, TS-120, and TS-930.

Antenna SWR Measurement

Procedure for measuring Antenna SWR using the AT-250, including meter switch settings and power output.

Auto Tuning Procedure

Step-by-step guide for activating and performing the auto tuning function for optimal antenna matching.

SPECIFICATIONS

Technical Specifications

Key technical data including frequency range, impedance, insertion loss, power handling, and tuning time.

Accessories Included

List of accessories provided with the AT-250, such as remote cables, AC power cable, and grounding wire.