YouKits TJ5A User manual

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Youkits TJ5A SSB CW HF TRANSCEIVER
OPERATION GUIDE
TJ5A is a high-performance portable multi-band SSB/CW transceiver, used with DDS as
LO, offering wide frequency coverage and fine tuning rate. The Doubly Balanced Diode
Ring Mixer makes strong signal handling capability possible.
Features:
Removable Battery Pack
Low RX current Drain
High-Performance AGC
40 Memories
Dual VFO
Memory-VFO Transfer
Operating Frequency:
Wide Band RX
3.500000 - 29.699990
TX / Narrow Band RX
7.000000 – 7.300000
14.000000 – 14.350000
21.000000 – 21.450000
28.000000 – 29.700000
Mode:
LSB, USB, CW
Tuning Rate: 10Hz, 100Hz,
1kHz, 10kHz, 100kHz
IF: 9 MHz
Sensitivity: 0.3uV Operating Power: 10.5 – 12.5V
Current Drain:
MODE CURRENT
RX 0.26 A
TX 4 A
Output Power:
MODE OUTPUT
SSB 0.1 – 20W
CW 0.1 – 10W

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1. Face Panel
Knobs
VOL - Volume control. Turn clockwise to increase volume.
TUNE – The big knob on the right side is Frequency tuning knob/Tuning rate selector.
Rotate clockwise is frequency up, counter-clockwise frequency down. Press the knob to
select the tuning rate. The sequence is 10Hz, 100Hz, 1kHz, 10kHz, and 100kHz.
PWR – Transmission power control. Turn clockwise to increase the drive. TX power can
be adjusted from 0.1 – 10W (CW), 0.1 – 20W (SSB).
RIT – RX increment tuning. Variable range: +260 Hz / -150Hz
Keys
MOD - Mode switch. Press to select LSB, USB and CW. In CW mode, the displayed
frequency is exactly the sender’s frequency. In CW mode MIC is disabled.
A / B - VFO selecting / Memory clearing. Press to select VFO A or VFO B. In MEM state,
hold the button until all the memories are cleared.
V / M - VFO/MEM switching. Press to switch between VFO and MEM. Turn TUNE to
select the memory number.

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MEM - Frequency saving / MEM to VFO transfer. Press to save the frequency to the
memory. Press MEM, the memory number appears. The dashes indicate the blank state
of the memory. Turn TUNE to select the MEM position you want to store the frequency to.
MEM00 - MEM39 can be used to store the frequency. Frequency saving can be canceled
by pressing MOD or STEP.
In the following case, MEM01 is not vacant. A frequency 14.200.000 is saved in this
position. You can rotate TUNE knob to find a vacant position.
How to transfer the frequency in MEM to VFO A or B? First, press V/M to enter MEM
state. Second, press MEM to find the VFO’s. Now VFO A or B appears on the left corner
on LCD. (A or B depends on which VFO is in use before pressing V/M. Third, press A/B
button or rotate TUNE knob to select the VFO you want to transfer the memory to (either A
or B). Fourth, press MEM to transfer the frequency in the memory to the VFO you have
selected. Finally, press V/M button to enter the VFO to which you have transferred the
frequency.
Let us study the following example:
Transfer MEM00 (18.068 ) to the VFO B.
Press MEM, and the following data is displayed:

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Select VFO B by pressing A/B button or rotating TUNE knob.
Press MEM to transfer MEM 00. The following is displayed:
Press V/M to enter VFO B.
Sockets
KEY – CW key socket. Use 3.5mm stereo plug. The ring is KEY; the sleeve is GND. The
tip has no connection.

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PH - Earphone/speaker 3.5 mm socket. Either earphones or speaker can be used. When
the earphone or speaker is plugged in, the speaker in MIC is disconnected. The tip and
ring are in parallel. The sleeve is GND. The stereo earphones can be used. Never use the
3.5mm mono type plug. The long plug sleeve short-circuits the ring connection.
The speaker can be connected to either the tip or the ring, since tip and ring are in parallel.
Never use the 3.5mm mono type plug. The long plug sleeve short-circuits the ring
connection.

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2. Switch and Socket on Right Side
MIC - External MIC/PTT/SPK socket. The supplied handset is also used as the speaker.
When the front PH socket is used, the MIC speaker is disconnected.
ON - When the switch is set at this position, the power is switched on, and the rig works.
OFF - When the switch is set at this position, the power is off. The rig stops working.
ANT Socket – The M16 socket on the right side is the antenna socket. Connect 50 ohm
antenna to this connector.
3. Socket on Back
DC IN - External power supply and battery socket

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IMPORTANT!
The power supply socket on the back (DC IN) has three pins: the “+” pin (left) and “-”pin
(right). The pin in the middle is also “-” pin which is for battery operation.
For DC12.5V external power supply operation, use the 3-pin connector. The left pin is “+”,
and the right pin is “-”.
For battery operation, use the 2-pin connector. The connector should be connected to the
left pin (+), and middle pin (-). NEVER use the middle pin as “+”!

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The two supplied white plastic bushes are used to prevent the paint from scratching by the
battery cabin screws. Put them on the screws before fastening the cabin to the transceiver
back.

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4. Operation
If you do not have the battery pack, use a DC 12.5 V power supply (The battery pack is
optional. Not included in the rig).
Warming-up time
It takes about 10 minutes for the TJ5A to stabilize. A drift of 10 – 20 Hz might be noticed
during the warming-up period.
To receive signal
Connect the antenna and turn on the power. Signals or noise can be heard. Rotate the
TUNE knob to the frequency you want. For compactness, TJ5A has no band switch.
Therefore, use fast tuning rate (For example, 10 kHz or 100 kHz) as the band switch to get
to the meter band so as to save time, and then use the fine tuning rate (10 Hz, 100 Hz, 1
kHz) to search signals or
tune accurately. Rotating RIT
facilitates +260 Hz/-150Hz
frequency shift. However,
RIT does not affect
transmitting frequency. In
transmission the shift is
canceled automatically. RIT
is usually set in the middle
position.
TJ5A is pre-set to broadband receiving, covering from 3.5 – 29.7 MHz. However,
narrowband receiving is possible by re-arranging the jumper caps on the main board.
Open the upper cover of TJ5A, the jumper caps are easy to find. Remove the caps from
JP3 and JP4. Place the caps on JP1 and JP2 to select narrow band receiving. In this case,
TJ5A operates in 40, 20, 15, and 10 meter segments:
Meter Band Frequency Range
40m 7.000000 – 7.300000
20m 14.000000 – 14.350000
15m 21.000000 – 21.450000
10m 28.000000 – 29.700000

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This picture indicating the caps in broadband receiving position
The LED at the right corner of the main board indicates the IF working state. It flashes at
very strong signals because of the AGC function.
To transmit signal
TJ5A transmits in the following frequency range:
Meter Band Frequency Range
40m 7.000000 – 7.300000
20m 14.000000 – 14.350000
15m 21.000000 – 21.450000
10m 28.000000 – 29.700000
Note: The band pass filter is tuned to the center of the band. Therefore, the transmitting power might be
affected at band edges.
SSB operation
In LSB or USB mode, press PTT to enter transmission mode. Speak to the MIC and your
voice is transmitted. Output power can be observed on the power meter. The output
power can be adjusted through PWR knob. Do not operate CW key in LSB or USB mode,
because the side tone from the speaker goes into MIC, causing a strange CW signal, the
combination of 950 Hz and the carrier.

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CW operation
In CW mode MIC is disabled. Press the CW key and the CW signal is transmitted. A 950
Hz side tone can be heard from the speaker. The side tone level is not controlled by VOL.
It is pre-set to a certain
level. The level can be
adjusted to meet the
personal desire. If the
level does not suit you,
trim VR3 on the main
board to obtain your
desired level. Open
the upper cover the
TJ5A. Find VR3. Set
the power level to the
lowest. Press KEY and
trim VR3 until the desired side tone level is obtained.
IMPORTANT!
Never try the long key at the full power output. This would overheat the power transistors.
Always use half or lower power to tune the tuner.
Youkits
2014-9