Lab599 Discovery TX-500 User manual

HF/50MHz Transceiver TX-500
USER MANUAL
v03.2021

2
Searching for Keywords
Search for keywords such as "Interface" and "menu” to nd a topic. If you are using
Adobe Acrobat Reader to read this document, press Ctrl+F on Windows
or Command+F on Mac to begin a search.
Navigating to a Topic
View a complete list of topics in the table of contents. Click on a topic to navigate
to that section. To return to the table of contents click on the page number.
Printing this Document
This document supports high resolution printing.
LEGEND
W Warning A Important INote
Using this Manual
This content is subject to change.
Download the latest version from
https://lab599.com/downloads/
If you have any questions about this document,
please contact Lab599 by sending a message to [email protected].
Copyright © 2020 Lab555 All Rights Reserved.

3
Table of Contents
Introduction ........................................................................................................................... 5
Controls end user interface ............................................................................................ 6
Device body and controls .............................................................................................. 6
User Interface ................................................................................................................. 8
Protections........................................................................................................................... 10
Basic Operations ............................................................................................................... 12
Getting Started ............................................................................................................. 12
Using the Menu ............................................................................................................ 12
Band Selection ............................................................................................................. 12
Mode Selection............................................................................................................. 13
VFOs A and B................................................................................................................ 13
RIT ................................................................................................................................. 14
XIT ................................................................................................................................ 14
VFO lock/unlock ........................................................................................................... 14
Transmit Settings......................................................................................................... 14
Receive Settings........................................................................................................... 16
Advanced Operating........................................................................................................ 18
Frequency Memories.................................................................................................... 18
DIG MODES (Audio Data Modes)................................................................................. 18
Split and XIT ................................................................................................................. 18
Receive Audio Equalization (RX EQ)............................................................................ 19
Transmit Audio Equalization (TX EQ).......................................................................... 19
Cross-Mode Operation ............................................................................................... 19
External power amplier control ................................................................................. 20
CW keyer memory ........................................................................................................ 20
Voice message memory .............................................................................................. 21
Accessories.......................................................................................................................... 22
Firmware Upgrades.......................................................................................................... 24
Remote Control.................................................................................................................. 25
Menu Functions ................................................................................................................. 26
00. Valcoder.................................................................................................................. 26
01. IF DSP ..................................................................................................................... 26

Table of Contents
4
02. CW Pitch ................................................................................................................. 26
03. CW Speed................................................................................................................ 26
04. CW Weight .............................................................................................................. 26
05. CW Key.................................................................................................................... 26
06. AGC ......................................................................................................................... 27
07. RF ............................................................................................................................ 27
08. Power...................................................................................................................... 27
09. GAIN........................................................................................................................ 27
10. NR Level.................................................................................................................. 27
11. NB Level.................................................................................................................. 27
12. SQL.......................................................................................................................... 27
13. VOX L ...................................................................................................................... 27
14. VOX ......................................................................................................................... 27
15. AM/FM .................................................................................................................... 28
16. CMR Level............................................................................................................... 28
17. Save Band VFO....................................................................................................... 29
18. EQL.......................................................................................................................... 29
19. RPAN ....................................................................................................................... 29
20. TPAN ....................................................................................................................... 29
21. TIME........................................................................................................................ 29
22. Corr TIME................................................................................................................ 29
23. TX Metr ................................................................................................................... 29
24. Type Tone ............................................................................................................... 29
25. VOX ......................................................................................................................... 30
26. Beep Key................................................................................................................. 30
27. Backlight................................................................................................................. 30
28. Contrast .................................................................................................................. 30
Maintenance........................................................................................................................ 31
Specifications...................................................................................................................... 33
FCC information ................................................................................................................ 35

5
Introduction
On behalf of our development team, we want to thank you for choosing the TX-500 Discovery.
The TX-500 is an ultra compact all-mode transceiver ideal for travelling. Its compact size
and weight mean that you can take the instrument to remarkable places, where radio work
will give you an unforgettable experience.
The strong casing, protection against splashes and dust ensure the use of TX-500 in extreme
conditions and guarantee its reliability. A sharp monochrome display will allow you to clearly
see the information in either bright sunshine or low light, thanks to a multi-mode backlight.
The transceiver parameters and functions will also make it possible to successfully use the
unit at a home station or as a mobile version. Record-low current consumption in reception
mode (up to 110 mA) will extend the battery life, providing for longer stay on the air without
recharging.
Because the TX-500 is a software-dened radio (SDR), you can expand its capabilities using
computer applications and adding new features with free rmware updates. The TX-500
Discovery has an integrated high-performance spectrum analyzer, allowing you to see
signals before you hear them.
It’s high time to go off into the deep blue yonder, taking the TX-500 with you.

6
Controls end User Interface
DEVICE BODY AND CONTROLS
Front view
Top function keys
RIT/XIT On / Off
Clear RIT / XIT
VFO / Memory
Lock / Unlock VFO
Step VFO
Power On/Off
Band Up / Down
Basic mode
Passband filter
Menu mode
Receiver gain control (RX mode)
Monitor volume (TX mode)
Tune VFO A, B / Menu Settings
RX / TX offset
Bottom function keys

Controls end User Interface
7
Left side
DC 9-15V
Power supply
1 – GND
2 – DC IN (9-15V/3A max)
1 – SPEAKER – *
2 – MIC IN
3 – PTT IN
4 – SPEAKER +
5 – MIC IN (V+) **
6 – GND
1 – PTT IN
2 – PTT OUT
3 – AUDIO DATA OUT
4 – Q 5 – I
6 – AUDIO DATA IN
7 – GND
25
61
2
4
5
6
3
4 3
2
1
7
1
MIC/SP
Microphone / Speaker
REM
DATA
* Connect a speaker or headphones with the appropriate pins 1 & 4, SPEAKER (-) and SPEAKER (+).
Do not connect a speaker to ground, pin 6.
** For connecting an external electret microphone that requires additional power supply.
Right side
1
4
5
3
2
CW KEY ANTCAT
4
3
1
2
1 – GND
2 – RX
3 – +3.3V IN ***
4 – TX
1 – GND
2 – “•”
5 – “–”3 – NC
4 – NC Antenna (50 Ohm)
*** When connecting with a third-party USB adapter, make sure that an input voltage of 3.3V (10mA) is supplied to the pin.

Controls end User Interface
8
USER INTERFACE
Main display
1
2
4
3
6
5
7
8
9
19 — Function buttons
2— Information bar title
TX/RX mode
Clock
battery low
Autogain control
(delay 1-10)
Hight temperature
alert
Clock
Supply voltage
Step VFO (Step RIT/XIT), Hz
or LOCK VFO
VFO offset, Hz (RIT/XIT)

Controls end User Interface
9
3— VFO A / B
VFO A
Basic VFO
VFO B
4— Info block 1
Basic modes or alternative modes:
Filter band width Receiver gain (0-100)
Monitor (0-100)
Radio frequency gain
Volume (-50+5)
ABCDEFG
5— Graph bar
Power output (PWR),
SWR, MIC, ALC
Transmit mode:
Power output (NUM),
SWR (NUM)
Receive mode:
S-meter
6— Info block 2
A
C
B
D
F
G
E
L
I
J
K
– Noise reduction ON
– Noise blanking ON
– Notch filter ON
– Attenuator ON
– Monitor ON
– VOX ON
– Speech compression ON
– Preamp ON
– Squelch ON
– Split mode effect ON
– Virtual intermediate frequency ON
7— Pan-adapter
Receiving or transmission channel
8— Menu
Menu Up Menu Down
– Function buttons

10
Protections
OVERVOLTAGE PROTECTION
When exceeding 15.0 volts, the transceiver won’t allow switching to TX mode, (the voltage
indicator on the display will become inverse) a signicant excess (more than 16 volts) it can
cause the protective fuse to burn out, as well as the failure of the transceiver! Use a power
source or battery with a voltage of 9 to 15 volts and a current of at least 3 Amps.
AATTENTION! Exceeding the supply voltage above 15 volts can damage
the transceiver!
REVERSE POLARITY PROTECTION
If you connected a minus voltage source or battery instead of a plus, the transceiver will not
turn on. You must connect the external power supply correctly, please, see the pinout of the
power connector in the section “Controls end user interface”.
OVERHEAT PROTECTION
The transceiver has an internal protection against the overheating of the output stage of the
transmitter. If the TX continuous mode is too long, the output stage as well as the transceiver
body can be heated up. If the limit value is exceeded (about 60 degrees Celsius), the trans-
ceiver won’t allow switching to TX mode. After the temperature drops, the TX prohibition
mode will turn off automatically.
AATTENTION! During long-term TX mode (digital modes) do not block the air
access to the rear cover of the transceiver, or reduce the power.
TIP: Unfold both rear legs to increase the air flow convection.

Protections
11
HIGH SWR PROTECTION
If the impedance of the antenna is different than 50 ohms and there is no antenna tuner
connected, the SWR indicator on the display will show a value greater than 1.0. If the SWR
value is 3.0 or more (the SWR indicator on the display will be inverse), the transceiver will
automatically reduce the power output. If the value of SWR is greater than 3.0, then the
output power will decrease more.
AATTENTION! Use a tuned antenna with a wave impedance of 50 ohms, this is ideal
(max output power), or use a matching device (automatic or manual tuner).

12
Basic Operations
GETTING STARTED
Before using the TX-500, you’ll need to connect a power supply, speaker-microphone and
an antenna, at minimum.
Power supply
Speaker-microphone
Connect
antenna
Unfold Leg
Left side
Right side
AF GAIN — Controls receiver AF gain (volume).
USING THE MENU
The menu is used to tailor the transceiver to your operating preferences.
To access the menu, push F until the any menu entry appears in
the pan-adapter area. To change the value of a menu parameter, rotate
MTUNE/MULTI (large knob).To exit the menu, push F again.
BAND SELECTION
The TX-500 covers the 160-6 m amateur bands. Characteristics of each band are summa-
rized below.
Best DXRang (Mhz)Band (m)
160
80
60
40
30
20
1.8-2.0
3.5-4.0
~5.3-5.4
7.0-7.3
10.0-10.15
14.0-14.35
Best DXRang (Mhz)Band (m)
17
15
12
10
6
18.068-18.168
21.0-21.45
24.89-24.99
28.0-29.7
50-54

Basic Operations
13
MODE SELECTION
Each mode is described briefly below. Later sections cover each mode in detail. Tap D
one or more times to select USB (LSB), CW (CWR), DIG, AM or FM mode. Long push selects
alternate modes, such as CW reverse (CWR). Also, long push returns normal mode.
• SSB: Single-Sideband modes are narrow-banded voice modes that conserves space in
crowded band segments. They’re the most popular modes overall, they are: LSB (lower-side-
band) usually used in 160, 80 and 40 meters, while other bands use USB (upper-sideband).
•
CW: Continuous Wave mode requires narrow bandwidth, providing a high signal-to-noise
ratio which is ideal for low-power (QRP) use. It’s also a popular mode for DXing and con-
tests. CWR Continuous Wave Reverse is the alternate mode, and may reduce the level of
interference (QRM).
• AM: Amplitude Modulation mode is characterized by good delity. It’s much less power-
efcient than SSB modes. You can easily nd AM amateur stations in 160, 80, 40 and
10 meters.
• FM: Frequency Modulation mode is most often used for local communications, and can
be found on 10 m and up.
• DIG: Digital Mode is usually used with a computer connected to the transceiver to send/
receive data. Although SSB modes can also be used for this purpose, the TX-500’s audio-
based data modes (E) optimize settings for data rather that voice.
VFOS A AND B
The TX-500 provides two VFOs. Use of VFO B is optional. Each VFO has independent fre-
quency, mode, and lter settings:
• VFO A normally controls both the receive and transmit frequency. Most contacts occur
between stations tuned to about the same frequency.
• VFO B can serve as a holding register for a second frequency of interest, then swapped
with VFO A as needed (see A<>B).
• + - Tuning rates: Tapping Kor L selects VFO tuning rate LSB, USB, DIG (10Hz, 100Hz,
1kHz, 2.5kHz, 5kHz), CW, CWR (1Hz, 10Hz, 100Hz, 1kHz, 2.5kHz), AM, FM (100Hz, 500Hz,
1kHz, 2.5kHz, 5kHz). SSB stations often align on 0.5 or 1.0kHz boundaries.
• A->B To copy VFO A’s frequency to VFO B: Tap N>A->B. Tapping also copies VFO A’s
mode and lter settings to VFO B as well.
•
B->A To copy VFO B’s frequency to VFO A: Tap N>
B->A
. Tapping also copies VFO B’s
mode and lter settings to VFO A as well.
• A<>B VFO A and B swap: Tap N>A<>B to exchange VFO frequencies, modes, and all
other settings.
IDue to the special feature of the internal signal conversion, there may be a certain
number of frequencies that can be heard in the headphones as clicks. This is not
a hardware problem, it is the features of the device architecture. In this case, we
recommend using the Kfunction.

Basic Operations
14
RIT
Incremental Tuning, or receive incremental tuning, provides a means of adjusting the receive
frequency without affecting your transmit frequency. This control is sometimes called a
clarier since it can be used to tune in SSB voice signals. But RIT can also be used in all
modes, in the event that a station calls you slightly off-frequency. RIT and XIT use the tuning
rate (1/10/100/200/300 Hz), taping Kor L.
XIT
XIT or transmit incremental tuning, adjusts the transmit frequency without affecting the
receive frequency. RIT and XIT use the tuning rate (1/10/100/200/300 Hz), taping Kor L.
• To use RIT or XIT: First, tap G RIT (RX mode) or tap G XIT (TX mode).
This turns on the “+0” on the display. Then adjust the offset using RIT/XIT knob.
• To zero the RIT/XIT offset tap H.
JVFO LOCK/UNLOCK
When the mode is activated, the inscription appears in the upper line of the display J (lock),
frequency tuning is not possible. To deactivate the mode, press the button J again.
TRANSMIT SETTINGS
• Voice Modes (SSB, AM, FM): Choose a mode: Tap D to select A / B, For G
mode.
• MON, Monitor: Push N>MON in the bottom line for MON on. Hold PTT to set the voice
monitor level, rotate MAF GAIN knob. High MON settings may result in audio clipping or
distortion. Start with 3 to 5.
+
<< TONE MON >>
F
ADo not use the hand speaker-mic at the same time as monitor Ffunction in
voice modes (ABFG) — this creates the risk of audio coupling with high
noise levels, distorting the real sound.

Basic Operations
15
• Adjust mic gain level: Push METR and select MIC, rotating MTUNE/MULTI.
CMR VOX L VOX D METR
Menu Up Menu Down SubMenu
TX Metr MIC
While speaking into the mic, adjust F>09 > Gain > MIC (mic gain).
+
While speaking, adjust mic gain for maximum 5-7 bars on a scale. Mic gain for the TX-500
mic is typically 3-7.
• CMR Speech compression: To use speech compression, tap N>CMR in the top line.
Adjust the level using the F>16 > CMR Level or long push N>CMR. High CMR
settings may result in distortion. Start with 1 to 3.
• POWER: Set the power level (10-100%): tap POWER in the top line and rotate the knob
MTUNE/MULTI. Do not use MIC gain to set power level. Set mic gain to a xed level as
described above.
• VOX: Selects push-to-talk (PTT) or voice-operated (VOX) transmit (G icon on). VOX
hold time is set with F>14 VOX > MIC (time, ms). F>13 VOX L (VOX level)
should be set to trigger at normal speech level, but not in response to incidental noise.
Start with low settings (80-90).
• VOX Transmitter keying method: The VOX switch selects either VOX or PTT keying for
CW mode. Most operators use VOX, allowing the transmitter to be keyed immediately
whenever a hand key or keyer paddle is used. Tap N>VOX_D in top line and rotate
TUNE/MULTI or tap F>14 > VOX > CW (time ms).
• METR: You can switch the transmit bar graph from MIC, ALC, PWR, SWR, PWR Num, SWR
Num, by tapping N>METR in the top line. Rotate MTUNE/MULTI knob.
• CW modes (CW, CWR): To swith modes tap D to select C (CW normal). In some
cases an interfering received signal can be eliminated by switching to D (CW reverse)
using long push D.
• CWPITH: Set sidetone pitch using CWPITCH. The ideal pitch for most operators falls
in the range of 600-700 Hz. The receiver’s passband will be centered at the pitch you
select. Tap N>
CWPITCH
and rotate TUNE/MULTI or F>02 > CW Pitch (Hz). Set
sidetone volume using AF GAIN in TX mode, F ON.

Basic Operations
16
RECEIVE SETTINGS
• RF gain is normally left at (-0). Reducing RF gain may be useful in some strong-signal
conditions.
• SQL: Squelch is used to mute the receiver until a signal appears. The control adjusts the
signal threshold required for squelch to “open,” unmuting the receiver.
• IF DSP: Virtual Intermediate Frequency: Species the Mode of the Receiver.
ENABLE: This is the operating mode, utilizing all DSP features of the radio. This mode
uses a virtual Intermediate Frequency, which is offset from the operating frequency by a
few kHz. This is similar to ‘homodyne’ technology.
DISABLE: When IF is disabled, the radio operates in simple Direct Digital Conversion
mode, and has soft reduced performances.
• FILTER: DSP lter tuning functions (LF/HF) The (LF/HF) control is used to shape the
TX-500’s receive lter passband. In general, a narrow passband reduces interference
(QRM) and noise (QRN), while a wider passband improves delity. In voice modes, CW and
DIG modes long push E selects low-cut (LF) and high-cut (HF) frequency. Pushing
E select number of lter (1-4)RX, (1-2)TX. These functions remove low- or high-
pitched interfering signals. Reducing the width or shifting the passband may attenuate
an interfering signal above or below the desired one.
• PRE/ATT: Preamp Land Attenuator D turns on the RF preamp. It should be used
only when signals are very weak. Preamp gain can be set on a per-band basis. Dturns
on the 20-dB RF attenuator, which can protect the receiver from strong interfering signals.
• NR: Noise reduction removes random background noise (hiss or static). It has a charac-
teristic “hollow” sound. Higher settings may attenuate weak signals. Tap N>NR turns
on noise reduction, holding N>NR and displays its setting, which can be adjusted
using the knob MTUNE/MULTI. Tap return to exit the setting display. Tap N>NR again
to turn noise reduction off.
• NB: Noise blanking C can eliminate repetitive noise such as that from power lines,
appliances, and vehicle ignitions systems. The NB setting is adjusted in the same way
as NR (see above).
• NF in SSB and AM modes, B turns on auto-notch, which locates and suppresses
one or more carriers automatically, Push N>NF to enable or disable the Notch Filter.
• TONE (Transmission tone): The transceiver will transmit a single tone. Pressing “Tone”
N>TONE again puts the transceiver in RX mode. A long press of TONE displays the
selection mode NORMAL (1000 Hz) or DUAL (two tones of 1000 Hz and 2000 Hz). The
transmission power is approximately 50%.

Basic Operations
17
EXAMPLE
(RX) SSB FILTER ADJUSTMENT: (CHANGE FIL-3)
Set FIL-3: Bandwidth: 2.4 kHz; Passband: 600Hz to 3kHz
1. Long-Push E to enter lter
adjustment menu. The parameter to
be adjusted is shown in the bottom
line of the display.
Menu Up Menu Down NumFil Sel
RX SBB FIL-1 LF 600
E
2. Push N>NumFil until FIL-3 is
selected (in the bottom line).
Menu Up Menu Down NumFil Sel
RX SSB FIL-3 LF 600
3. Push N>Sel once to select “HF”.
The display might now look like this:
“ RX SSB FIL-3, HF2700”. (‘2700’
might be any other value).
Menu Up Menu Down NumFil Sel
RX SSB FIL-3 HF 2700
4. Rotate MTUNE/MULTI to change 2700
to 3000 (notice the frequencies are in
Hz, not in kHz).
Menu Up Menu Down NumFil Sel
RX SSB FIL-3 HF 3000
5. Push E to save changes and exit the lter adjustment menu.
6. CHECK YOUR WORK: Push Ea
few times until FIL-3 is selected. It
should now display 2.40 k.
E ×3

18
FREQUENCY MEMORIES
V/M (VFO/Memories) — The TX-500 has 100 general-purpose frequency memories (00-99),
Each memory stores VFO frequency, modes, and other settings.
To store a general-purpose memory (00-99): Push I, then locate the desired memory by
rotating the MTUNE/MULTI knob. The VFO frequencies presently stored in each memory will
be shown as you scroll through them. When you reach the desired memory number, push
N>VFO->Mem to nish, or tap I to cancel.
Mem->VFO VFO->Mem
80 ---.---.---
To recall a general-purpose memory: Push I, then select memory 00-99 using MTUNE/
MULTI. Tap I to exit.
To erase a general-purpose memory: While scrolling through memories to save or recall,
push H.
DIG MODES (AUDIO DATA MODES)
Many audio-generated data transmissions can be heard on the bands, using PSK31, RTTY,
JT65 and other modes. A computer,sound card, and appropriate software are normally used.
DIG mode is provided for this purpose.
Unlike SSB modes, DIG disables MIC and enables use AUDIO cable (connector REM/DATA).
AUDIO CABLE
Also DIG mode has individual audio level settings. Upper sideband is the default.
09 > Gain > DIG (level settings)
RX / TX switching can be via CAT cable (see Remote Control). You can also use the VOX
function (see Basic Operations).
DIG mode settings: tap F>13 VOX L > DIG > (vox level)
F>14 VOX > DIG > (time, ms)
SPLIT AND XIT
Sometimes you’ll hear a DX station being called by many other stations. To ensure that he
has a clear transmit channel, the DX station may say “UP” or “DOWN” to indicate that he’s
listening above or below his transmit frequency.
Advanced Operating

Advanced Operating
19
To use split, rst tap N>A->B to set VFO B to the same mode, frequency, and lter set-
tings as VFO A. Then tune VFO B up about 2 kHz. Finally, tap N>SPL (the J icon will
turn on). VFO B is now controlling your transmit frequency.
This is where the A<>B switch comes in: it reverses the A and B VFOs so that you’re tempo-
rarily receiving on your transmit frequency. During this time, tune VFO A around a bit to see
if you can identify who is presently working the DX station, then position yourself just above
this frequency. With any luck your next transmission will occur right where he’s listening.
XIT as an alternative to split: If you’re trying to preserve VFO B as a holding register tuned
someplace else in the band, you may want to use XIT rather than split in the above situation.
In this example, you’d turn on XIT and rotate the offset control to about +2.00 kHz. You’ll
then be transmitting 2 kHz above VFO A. To do the equivalent of A<>B, you can briefly turn
RIT on as well. Turn off RIT to listen to the DX station.
RECEIVE AUDIO EQUALIZATION (RX EQ)
The TX-500 provides 3 bands of receive audio equalization via the F>18 EQL > RX
menu entry. EQ RX can compensate for physical acoustics (of the room, headphones, internal
speaker, external speaker), tailoring the audio to your personal preference.
TRANSMIT AUDIO EQUALIZATION (TX EQ)
If required, transmit audio equalization can compensate for microphone and voice variations.
F>18 EQL > TX works exactly the same as EQ RX, and can be used during transmit. EQ
TX is not applicable to CW. While adjusting EQ TX, monitor your voice using headphones (use
N>MON to set the level), or listen to your transmitted signal on another receiver. If you hear
distortion, reduce all EQ TX bands. You may also have excessive mic gain or compression.
AMost microphones, including the TX-500, will provide good audio quality with little
or no EQ TX. High settings can cause distortion.
ADo not use the hand speaker-mic at the same time as monitor Ffunction in
voice modes (ABFG). This creates the risk of audio coupling with high
noise levels, distorting the real sound.
CROSS-MODE OPERATION
(CW-in-SSB) Cross-mode operation is possible in some cases. For example, you could set
up VFO A for SSB receive, and VFO B for CW transmit, then enter N>SPL.
SPL

Advanced Operating
20
EXTERNAL POWER AMPLIFIER CONTROL
To control the PTT function of the power amplier, you must connect pin 2 (PTT OUT), open
collector, of the REM / DATA connector to the PTT control relay of the external power amplier
(usually this is the "PTT" connector). Also, pin 7 (GND) of the REM / DATA connector must
be connected to the GND of the external power amplier.
It is also necessary to connect the BNC type "ANT" connector of the transceiver to the am-
plier input (usually named as the "TRX" connector) with a 50 Ohm coaxial cable.
HF Amplifier
Coaxial cable 50 Ohm
If the amplier does not have an automatic band detection function, then it must be selected
manually.
Note: Connecting cables are not supplied.
AATTENTION! The maximum switching voltage must not exceed 25 V and the
maximum switched current must not exceed 0.5 A
CW KEYER MEMORY
For recording and later playback of the short CW messages, the TX-500 provides 4 memory
slots with a duration of 25 seconds.
To record, you need to press and hold one of the "CWM" keys 1, 2, 3, 4 for more than 1 one
second. The REC icon appears on the screen. Then, you can perform your own CW manip-
ulations, and at the end, press shortly the same "CWM" 1, 2, 3, 4 key.
To play a recorded message, press shortly one of the "CWM" 1, 2, 3, 4 keys. The PLY icon
will appear on the screen. Pressing shortly will stop playback.