YouKits TJ2B Instructions for use

CONSTRUCTION OF TJ2B HANDHELD SSB TRANSCEIVER
The TJ2B is a high-performance QRP portable multi-band SSB transceiver using DDS as
the LO, and offering wide frequency coverage and fine tuning rate. The Doubly Balanced
Diode Ring Mixer makes strong signal handling capability possible. The TJ2B is a
pre-assembled kit. You need only assemble a few parts and connect some cables to be
qrv.
Operating Frequency: 3 - 18.2 MHz (Kit A)
Mode: LSB, USB, CW (RX)
Tuning Rate: 1Hz, 10Hz, 100Hz, 1KHz, 10KHz, 100KHz
IF: 9 MHz
Sensitivity: 0.3uV
Current Drain: 260 mA (RX)
Operating Power: 10 - 13.6V
Output Power: 5W
40 Memories
Dual VFO
Memory-VFO Transfer

Tuning steps of 1 Hz are available. Pressing the TUNE knob selects the tuning rate.
Included Hardware: Buttons, switches, DC sockets, earphone socket, pot, and encoder. A
miniature speaker is packed in the bottom cover of the enclosure.

Cables for internal connections
Components package

Toroids Note: FB-43-2401 may be supplied in the kit. This core is larger than FT-43-37.
Can Inductors

Pre-assembled Miniature Transformers (Packed in a separate plastic bag)
Brass Stand-Off Parts

Included DC cable as a free gift.
All the SMD have been assembled in the factory. However, some bulkier components,
such as the buttons,switches, can transformers, toroids, electro caps., have not been
assembled. Thess components prone to damage in transpiration if they were
pre-assembled. The users are required to solder them onto the PCB.
Let's start step by step.

1. DDS Unit
Assemble the following components: (C34 has no component)
1) Assemble Y1, the 2MHz crystal. Bend the leads before soldering. Otherwise it will be
too high.
2) Assemble MIC. Notice the Ground pin (the pin connected to the casing). Solder the
GND pin of the MIC to the GND pad of CN6 (the square pad on the left), and solder the
MIC pin to the MIC pad (the round pad). It is suggested to extend the leads so that the
MIC is closer to the MIC hole on the case. See illustration.

3) Assemble the 3.5mm stereo socket to J1. This is the external MIC and PTT socket.
Because of the manufacturing process, the top cover opening for J1 cannot be lower. It is
suggested to modify the socket a little so as to align with the opening better. It takes only 2
or 3 minutes. First, cut off the 5 tiny plastic stands-off on the socket. Second, flatten the
plastic rim with a file. See the illustration below.
Assemble the modified socket to J1. Push the socket to the MIC side as much as possible
until the side aligns with the silk line before soldering. See the illustration below.

4) Solder a 220uF electrolytic capacitor to C7 pads. (C7 may have been assembled).
5) Solder a miniature transformer to T1 pads. Six such transformers are supplied in the
bag. Use one of them here.
6) Insert the LCD cable to the FFC socket (CN3). Do not assemble the buttons until the
LCD is assembled. Bend the flexible cable before inserting it into the socket.
Pull the lock bar to release the lock of CN3.

How to insert the LCD Cable
Never bend the cable end soldered to the LCD!