Unified Microsystems XT-4Beacon MK 2 Manual

UM
Unified
Microsystems

Specifications

Power: +7VDC to +15VDC, 5ma typical
CW speed: Selectable 5, 10, 15, 20, 25 WPM
Memory size: Approximately 960 Morse letters
Output keying: Positive Keying only, RCA phono jack output
Paddle input: 1/8" (3.5mm) stereo jack input
Note: The XT4-Beacon comes pre-programmed with a test message. Verify that
the message plays back properly before attempting to program a new message.

Set UP

1. Wire up your paddle with shielded cable with two conductors. The XT-4Beacon uses a 1/8" stereo plug. The shield wire is
ground. The tip of the connector is for the dit contact and the center ring is for the dah contact.
2. Wire up a cable to the CW input of your transmitter. Use shielded cable with an RCA phono type connector for the keyer
end and a connector compatible with your transmitter CW Key input jack on the other end.
3. Wire power to the pads marked + and – on the end of the board opposite the connectors. Be sure to observe correct
polarity and voltage limits.
Note: The XT-4Beacon is designed to work with solid state positive keyed radios only! Damage can occur to the XT-4 Beacon
and/or your transmitter if it is used improperly!
If you are unsure of your transmitter type, plug the CW cable into the transmitter but leave the other end free. Measure the voltage
across the other end of the cable. Ground is the outer shield, and the inner wire is positive. The voltage should measure +5V to
+12V. If the voltage is negative, or is more than 24V, do not use the XT-4Beacon keyer with your radio.

Speed Control

CW speed is controlled by the small trim pot marked R4 on the circuit board. Turning the pot clockwise will increase the speed in 5
WPM increments from 5-25 WPM. Note that the "20 WPM" speed is actually set for slightly less than 20 WPM. FCC regulations
require repeater CW ID and some other application be less than 20 WPM. Setting the XT-4B to the 20 WPM setting will ensure
compliance.
Start with R4 fully counterclockwise. Press the dit paddle and slowly turn the trim pot clockwise. The speed will start at 5 WPM. As
the pot is advanced, the speed will suddenly increase to 10 WPM, followed by 15 WPM, 20 WPM, and finally 25 WPM. Leave the pot
setting at the desired speed. For best results, leave the trim pot setting near the middle of the desired speed setting.

Jumper Selection

Operation of the XT-4B is controlled by jumpers on J4. The pin definitions are as follows:
Pin #
1
2
3
4
5
6
Pin 1 is the one nearest the corner of the board. See Figure 1 for location of the jumper pins. To select a function, connect the
XT-4Beacon MK 2 ID Keyer
Description
Play message
5 second key down followed by recorded message.
20 second key down followed by recorded message.
Play message every 10 minutes
Record
Ground (GND)
Version 1.00
September 2023