Preppcomm Dmx-40 User manual

Making Communications Fun Again!

QUICK START GUIDE

By Eric C Anderson, PreppComm

Version 3.0, August 2021

BEFORE YOU BEGIN:

Decision Time

QRP Transceiver

Base Station Decoder/Encoder?

Before you start into the Quick Start Guide, let’s decide how you are going to use it?

There are two sections to the guide:

1. QRP Transceiver: Getting started using your DMX-40 as a QRP (low power)

Transceiver on 40 meters. This is referred to as the "Transceiver Mode." In this

use, you only need the DMX-40, the keyboard, a set of headphones or powered

speaker, and an antenna (or dummy load if you are learning how to use it). Go to

Section I below.!

2. External Transceiver Decoder/Encoder: This is for when you want to

connect your DMX-40 to your base station transceiver to use as a CW decoder/

encoder. This is referred to as the "External Mode or Companion Mode." This

mode enables use of the internal computers for decoding and encoding, and uses

the receiver and transmitter inside your base station transceiver. This allows the

decoder and encoder to operate on any band your base station operate on, and at a

higher power level, set by your base station. Go to Section IV for setup.

Page 2

I. Section I: QRP Mode Setup

1. Set up the DMX-40 as shown in Figure 1 below. Do not apply too much force

when plugging in the keyboard - make sure you have the USB plug correctly

oriented and aligned. Do not apply any downward pressure.

FIGURE 1: STATION SETUP AS STAND-ALONE STATION

2. Turn on the transceiver using the RED power switch.

WARNING: NEVER OPERATE THE TRANSMITTER WITHOUT A LOAD ON THE

ANTENNA CONNECTOR. DOING SO VOIDS YOUR WARRANTY FOR ANY

DAMAGE CAUSED BY AN UNLOADED TRANSMITTER.

If you plan to use a key to transmit, this will be covered at the end of this section.

Page 3

Note: You can turn off the internal transceiver by pressing the frequency button until it

says "External." This is what we refer to as External Mode, or Companion Mode, and is

discussed in detail in Section II. Pressing it again restores transceiver function

The Splash Screen will display for approximately 3 seconds, as shown in Figure 2

below.

FIGURE 2: SPLASH SCREEN

The Main Screen then is displayed, as shown in Figure 3 below.

FIGURE 3: MAIN SCREEN

3. Press the Menu Button, and the Main Menu screen will display, as shown in

Figure 4 on the following page.

Page 4

FIGURE 4: MAIN MENU

4. Press the LOCAL STATION SETUP button at the top of the menu. The Call Letters

entry screen will display, as shown in Figure 5 below:

FIGURE 5: CALL LETTERS ENTRY SCREEN

5. Enter your call letters assigned to you by the FCC. Use backspace or delete to

edit if you make a mistake. Note: you do not have to hold down the caps key - all caps

is automatic. Press the NEXT button to continue.

6. Using the NEXT buttons, proceed through a series of screens and enter the

required information

a) Name, or in ham radio lingo, your Handle, such as JOHN

b) Location, or QTH in ham lingo, such as CHICAGO, IL

c) Rig Type (PREPPCOMM DMX-40)

Page 5

c) Antenna Type. If you don’t have an antenna yet, put NO ANTENNA.

d) License Level. Select your FCC license level

The License Level Entry screen is shown in Figure 6 below.

FIGURE 6: LICENSE LEVEL ENTRY SCREEN

7. Press the FINISH button on the License Level Screen

You will be returned to the Main Screen. You have now completed initial setup of your

DMX-40 transceiver. Before we proceed, it is important to understand how the

Frequency Button works (see Figure 3).

The Frequency Button

The DMX-40 can be thought of as two separate parts: the computer part, and the

transceiver part. The computer portion is always active when power is on. When you

see a frequency value in the Frequency Button, the transceiver section is also enabled,

and the receiver or transmitter is active, depending on receive/transmit state. .

However, when you see the word "External" instead, the internal transceiver, both

receive and transmitter, are inactive.

External Mode aka Companion Mode is useful for experimenting with the operation of

the DMX-40 without causing interference on the band, or when using the DMX-40 with

an external transceiver, allowing the computer section to control that external

transceiver by sending Morse code to it via the KEY IN/OUT jack, and listening to its

receiver via the AUDIO IN jack. Switching between Normal and External modes is a

simple touch on the Frequency Button.!

Page 6

II. QRP Mode: Using the Transmitter

Also note: When in External Mode, the receiver is also disconnected.

In this section we are going to familiarize you with using the four different call and

answer functions built into the DMX-40.

1. Press CALL. On the status line, you will see the question SET CALL WPM = ?

Asking you to specify how fast to transmit, as there is no history to base that on at

this ﬁrst transmission, and the CALL button will turn RED."

2. Press SPACE BAR to set the default 20 WPM. You can change the default."

3. Watch as the DMX-40 transmits the general calling sequence."

4. Press CALL to end the sequence. Sequence continues until complete, and ends

with a Kappended. The CALL button will turn AMBER during the ending of the

sequence. K means "Anyone Come Back." Note that the general call will run until

you end it. Typically you will run it for 30 - 90 seconds when on the air."

5. Press NO CCS button and enter the call letters of a station you would like to call.

Press SPACE or FINISH to complete and return to the Main Screen."

6. Note the CCS Button now has the new call sign you just entered loaded. NOTE:

the decoder can also ﬁll the CCS button from a received station."

7. Press CALL to start the directed call sequence. Note it will automatically use 20

WPM from recent history."

8. Watch as the DMX-40 calls the speciﬁed station. Press CALL again to end the

sequence. Note that KN is appended at the end, which means "only the station I

am calling, come back.""

9. Press the ANS Button twice, quickly. The ﬁrst press will result in a RED button,

the second press will result in an AMBER button. Ignore the Type-Ahead Buffer

Pop-Up."

Page 7

IMPORTANT: Use a DUMMY LOAD or the External Mode while practicing CALL

and ANSWER functions. Press the Frequency Button until it says External. This

prevents accidental interference on the 40 meter band.

10. Watch as the DMX-40 transmits the answer-validate sequence. This is a short

station ID used when you are responding to another station’s CQ (general call) to

attempt to establish a 2-way communication. If they answer you, then a 2-way has

been established, and communication can begin. Answer Validate is not required if

you make a call and someone answers you."

11. Press ANS once. The button turns RED, and a Type-Ahead Buffer pops up.

12. Type a tilde (~) character, then press ANS again. The button turns AMBER."

13. Watch as the DMX-40 sends the initial station ID, followed by the INFO

microprogram, which is generated when you type in a tilde character. The Type-

Ahead Buffer goes away as soon as the tilde is read out. The ﬁnal station ID back

to the other station completes the transmission, with a KN."

14. Think up a short message, such as "HI, BOB. HOW ARE YOU TODAY?""

15. Press ANS and IMMEDIATELY type your message. You should be able to type at

least part of the message during the station ID, and then your message will begin to

transmit.

16. Press ANS again to specify your typing is complete. Your message will appear in

the Type-Ahead Buffer, until the station ID has completed, and then it will be read

out one character at a time."

17. You now have a basic idea of how to use the four main transmit functions:

1. General Call

2. Directed Call

3. Answer-Validate

4. Answer

These built-in microprograms (CALL, ANSWER, and INFO) can be customized and

controlled from function keys using RPL (Rig Programming Language) in our

microprogramming system. There are 12 user-deﬁned microprograms. Watch our

YouTube video on microprogramming to get a "starter set" to play with.

Page 8

III. QRP Mode: Using the Receiver

1. Background

Obviously, the ﬁrst thing you need to do to tune in a station is... remove the dummy load

(if you used one) and connect to a real antenna. A good antenna is a critical aspect of

any radio station. Since you are running QRP (Low Power), a good antenna is truly a

MUST.

One one level, tuning in a station is fairly simple: you scan up or down the band looking

for a signal, and stop and adjust around the signal so that it is decoding correctly. On

the other hand, it can be quite daunting.

Why can it be daunting? There are several reasons that you need to be aware of. First

and foremost is the "band condition." The band can be "open" or "closed." It depends

primarily on the sunspot cycle, the current sunspot activity, and time of day. If you hear

nothing on the band, the band is probably closed, or, as they say DEAD. Try later.

However, a dead band does not mean you can’t connect with someone nearby (local).

If you have a scheduled time and frequency to meet, even if the band is dead, i.e., long

distance communications is out, local can still work quite well, depending on your

antenna. Typically, the 40 meter band opens in early to mid afternoon, and is open at

various distances - ever growing farther and farther away - until very early morning. By

that I mean oh-dark-thirty. It’s all about the ionosphere and its height above the earth. It

rises at night, and thus your "skip" distance increases.

2. Receiver Incremental Tuning

You may have noticed after transmitting that the Frequency Button changes to show

RIT +0. RIT stands for Receiver Incremental Tuning. This decouples the receiver

frequency from the transmitter frequency. The transmitter frequency remains constant,

but you can make minor adjustments to the receiver frequency, as needed. Speciﬁcally,

when another station comes back to you the ﬁrst time, their frequency may be slightly

off, and you may need to adjust the receiver frequency to remain set for optimal

decoder operation. More on that below.

Page 9

NOTE: For this section, you will need a real antenna, and the Frequency button

should show a frequency value, not External. Press the button to switch to

Frequency Mode, which turns on the transceiver inside the DMX-40.

3. Receive Mode Keyboard Commands

Figure 7 below is a diagram showing the receiver keyboard commands. You can tell

that you are in Receive Mode because both the CALL or ANS Button are BLUE. Press

MENU / HELP / RECEIVE for a summary of these commands. The commands are on

two separate screens, which you can access via the NEXT and PREVIOUS buttons.

The EXIT button will return you to the Main Screen.

Note that on the Help Screen, there is also help for TRANSMIT and MICROPROGRAM

commands, as well.

FIGURE 7: RECEIVE MODE KEYBOARD COMMANDS

There is a large version of this layout in Appendix VI of the DMX-40 Reference

Manual you can use print out and as a guide. For now, just note the following keys:

a. the 4-way Receiver Frequency Control keys (bottom right)

b. the Gain Control keys, (to the left of the frequency controls)

c. the Restart Decoder (space bar) key.

Note that the initial frequency display shows 7.030000, which is 7.03 MHz, and the

initial frequency step size of 1 Hz. 7.03 MHz is the small signal calling frequency for 40

meters.

Page 10

4. Volume Controls

There are two separate volume or gain controls on the DMX-40. One controls the audio

volume going to the headphone jack. The other controls the signal gain to the decoder.

The default values are 10 and 30, and are shown at the bottom left and right of the Main

Screen (see Figure 3).

Try adjusting both now, using the keys with or without the shift key down, watching the

values change on-screen. For weak signals, increase the decoder gain to 40. For

strong signals, you may need to reduce below 30. Audio setting is for your preference.

5. Tuning Practice

1. Press the right arrow key. Note the frequency has increased to 7030001. You

have increased the receiver frequency by 1 Hz."

2. Press and hold the right arrow key, and after 1 second, auto-repeat on the

keyboard kicks in. Now you see the frequency step up in 1 Hz intervals."

3. Press the up arrow key once. You have now increased the step size to 10 Hz.

Note that the last digit has become a small zero. This is the visual indicator of the

step size. Repeat steps 1 and 2 with 10 Hz steps."

4. Press the down arrow key once. The step size has returned to 1 Hz steps."

5. Note: Typically, you will scan the band for a station by using 100 Hz, or even 1000

Hz steps. Do that now by pressing the up arrow key twice (two small zeros for 100

Hz steps), and holding the right arrow key down."

6. Test: See if you can return to 7.030000 on the Frequency Button. Practice moving

around. If you have a real antenna connected, check out 10 MHz or 5 MHz for

WWV. Hint: Go to 10,000 Hz steps to get there quickly. Note that outside the 40

meter band (7.0 - 7.3 MHz) the status line displays SW Listening for Short Wave

Listening.!

7. If you hear a Morse Code signal, adjust the frequency until you see the CW IN

LED light up and track the signal. Using 10 Hz steps, move up and down in

frequency steps to ﬁnd approximate center of where the LED lights up. Adjust the

decoder gain down if the CW IN LED is staying on between Morse Code tones (very

strong signal), or up if the decoder is missing some tones (weak signal) using the

Decoder Gain keys."

If you don’t hear any signals, try again later in the day when the band is open."

Page 11

8. When you ﬁrst tune into a new station, with CW IN LED blinking, press the SPACE

bar to restart the decoder. The decoder will start collecting data, and when it has

enough, it will determine the sender’s speed and measure 5 different factors related

to the speciﬁc style of the sender’s code. The decoder will then use that information

to fully decode the captured signal, and then continue in real time.

9. Any decoded Morse Code will appear on the screen in GRAY letters. If a

transmitting station call sign is detected, it will be captured automatically, and it will

show up in place of the NO CCS (Captured Call Sign) text in the CCS Button."

10. Do not be surprised by strange decodings. If you have not tried, it is hard to focus

on sending with your hand and thinking about what is the next letter in the word, and

thinking what is the next word... Sounds easy, but It is not, although practice makes

perfect. Also, there are a lot of stations that send what appears to be gibberish.

Often it is weather or other information. Look for conversations that sound like two

or more people talking, or call CQ.

6. Calling CQ

1. If you can’t ﬁnd anyone calling CQ, ﬁnd a quite spot on the band to transmit. Make

sure the Green ENABLED LED is lit up. This tells you that your license allows you

to transmit on this frequency."

2. Use the CALL Button to do at least a 30 second general call."

3. Listen for at least 30 seconds to see if anyone replies. Repeat. If you get no

response after 5 or 10 calls, try longer calls. Maybe the band is dead, or your

antenna is not working properly?"

4. If someone answers, use the left-right arrow keys to adjust the frequency of the

receiver for best decoder operation (you will be in RIT Mode automatically)."

5. When they pass back to you, use the ANS Button. You are one your way!

7. The Tuning Rule: Before You Answer a CQ

Calling CQ and having someone answer you automatically means you and they are on

the same frequency. You do not have to worry about the Tuning Rule. But if you are

Page 12

Always restart the decoder when tuning in a diﬀerent station to ensure proper

capture of the sender’s code.

answering someone else’s CQ, you need to make sure you are one the correct

frequency.

There are actually TWO frequencies where you can hear another station and have the

CW LED ﬂashing and the decoder happily operating. For example, if the other station is

transmitting at 7.03 MHz, you can tune them in at 1300 Hz higher or lower, or 7.031300

MHz or 7.028700 MHz. Just to keep things sane, we subtract 1300 Hz from the

receiver frequency, so it shows 7.03 MHz when tuned to a 7.03 MHz station with a 1300

Hz tone, but you can also tune the station 2600 Hz higher, at 7.032600 MHz and get the

same tone. Sound complicated? Well, OK. So just follow the Tuning Rule.

8. The Tuning Rule

1. If you made the call and someone answered, skip this - no rule required.

2. If you want to answer a call: If increasing your frequency one step makes the

received tone go DOWN in frequency, skip this.

3. If the tone went up, Press the Dkey to drop down 2600 Hz, and adjust your

frequency slightly to receive the other station accurately (make sure you are within the

decoding frequency bounds).

Experiment with this process by tuning in stations, then applying the Tuning Rule.

9. Getting it Right

Learning the ropes is a slow process. The best way to become comfortable with the

process is to practice. Practice practice practice! There are two major areas to

practice:

1. Operating the DMX-40: This is the easy part. Use the DMX-40 Reference Manual.

There is so much more the DMX-40 can do we have not touched on."

2. Tuning and Doing QSO’s: This is harder, because there is much to learn: what

are the best frequencies to use? What is the best time of day to operate? How to

identify different styles of operation? How to establish your own style? How to use

microprogramming to support your own style? This is the more time-consuming

part, but especially if you are a prepper, do it NOW, and do it FREQUENTLY so if

the S does HTF, you will be comfortable operating your communications safety net!!

Page 13

NOT using the Tuning Rule is the cause of many missed QSO’s (ham lingo for

an on-air conversation). Do not forget to do this step!

IV. External Mode Setup

Before you begin setup, you are going to need some cables and adaptors. You will also

need to determine if the "KEY IN" connector on your transceiver is a ¼" phone jack or

something else. We will assume here that it is. You will have to make adjustments if it

is something else. Likewise, we are assuming that any manual key you plan to use has

a ¼" plug on the end of its cable. Below are the cables you will need, Amazon product

codes, and a cable number we will use in the setup instructions.

Cable 1: KEY IN/OUT. This cable connects the DMX-40

KEY IN/OUT connector to two separate ¼" jacks. The

RED one (Right Channel) is for your external key, and

the BLACk one (Left Channel) we will hook up to your

base station. Amazon product code: B017IK07UC

Cable 2: This is a standard

3.5mm stereo Y cable, with a 3.5mm male stereo plug on

one end and two stereo 3.5mm female stereo connectors on

the other end. Amazon product code: B00GN76HAG. Any

stereo 3.5mm male to dual 3.5mm female Y cable will do.

Cable 3: Stereo 3.5mm cables 4 feet dual pack. Amazon

product code: B076BFZDG2. Any stereo 3.5mm cable with

two 3.5mm plugs (one on each end) will do. You will need 3

of these.

Adaptor Plugs: These are 3.5mm email to ¼" male stereo plugs. There

are 3 in the Amazon pack, product code: B08CKH55SX. These are

required if you have a ¼" jack on your Key In jack on your rig and/or a

3.5mm plug on your key. You may need all 3 of these.

On the following page, Figure 8 is a setup diagram showing how all this connects

together. Obviously, if you understand the diagram, you can arrange connections using

alternate cables, but if you are not sure, use the diagram exactly as shown.

Page 14

Remember: plug in the connectors carefully to the DMX-40 KEY IN/OUT and

AUDIO IN connectors, and do not press downward. This is to prevent accidental

damage of the connector and possible disconnection from the PCB.

Connection Sequence (referring to Figure 8 on previous page):

1. Connect power (12V) to the DMX-40. Use a 12V wall plug or battery. If using a wall

plug, Make sure it is not causing interference on your rig’s receiver.

2. Optionally, connect a 5W dummy load to the antenna connector on the DMX-40 (not

shown in the diagram). This is to prevent you from operating the transmitter without

a load if you forget to switch to External Mode.

3. Connect the provided keyboard to the DMX-40.

4. Turn on the DMX-40, and after it boots, ouch the frequency button so it says

"External."

5. Nothing is connected to the headphone jack on the DMX-40 in this setup, as the

transceiver inside is disabled. However, you also cannot hear the TONE OUT of the

DMX-40. A more complex setup is discussed later if you wish to mix your

transceiver audio and the TONE OUTPUT of the DMX-40.

6. Connect Cable #2 (Stereo Y Connector) to your transceiver headphone out jack,

using an adaptor plug if necessary.

7. Connect a stereo Cable #3 to one side of the Cable #2 Y and the other end of Cable

#3 to the input of your powered speaker.

8. Test to make sure your powered speaker is now generating the output signal from

your receiver.

9. Connect another stereo Cable #3 to the other side of Cable #2 Y, and plug it into the

AUDIO IN jack of the DMX-40.

10. Check to see if there is activity on the TONE LED of the DMX-40 when you turn in

noise or stations on your transceiver (you should also hear them on the powered

speaker).

11. Audio is now complete. If you do not plan to use the DMX-40 to transmit code,

but only plan to use your key, then you are done with setup at this point. Your

key remains plugged directly into your transceiver, as before.

12. Connect Cable #1 to the KEY IN/OUT jack on the DMX-40. Be careful to not stress

the KEY IN/OUT connector.

13. Plug your key into the RED jack of Cable #1.

14. Test your key. Press the key and see if the CW IN LED lights up when the key is

down.

15. Connect another stereo Cable #3 to the BLACK jack on Cable #1 using a 3.5mm to

¼" Adaptor Plug.

16. Connect the other end of the stereo cable to the KEY input jack on your transceiver,

using another 3.5mm to ¼" Adaptor Plug if required.

17. Test to see that by pressing your key, your transmitter is activated.

18. Key wiring is complete.

Page 15

Page 16

V. External Mode Using Mixing

As mentioned above, this wiring does not "mix" the TONE OUT sound from the DMX-40

with your receiver audio output before the combination is fed to the powered speaker.

There are a number of low-cost 4-channel mixers available on Amazon, either powered

or passive (unpowered). If you are interested in hearing BOTH the audio from your

transceiver AND the TONE OUT from the DMX-40, this is for you. Note that the

DMX-40 generates a tone output for either computer generated code or code from your

manual key.

An example of a powered mixer is Amazon Product Code B07QDN6Z83. An example

of an unpowered mixer is Amazon Product Code B08VJ44BSF. Both are near the $20

price tag.

Basically, rather than a cable #3 going directly from Cable #2 to the powered speaker, it

would go to one input on the mixer, and an additional Cable #3 would run from the

headphone jack on the DMX-40 to a second input of the mixer. The mixer output would

then connect to the powered speaker.

One of the mixers above uses ¼" phone jacks, the other RCA jacks, so the cables you

would need will depend on the mixer you choose.

The mixer will allow you to adjust the volume balance between the CW out tone and the

received signal.

Page 17

VI Operation in External Mode

1. Basics#

The tone that the DMX-40 is looking for is NOT 600 or 650 Hz, tones normally used for

listening to CW. Rather, it is 1300 Hz. Why did we mess your ears over by choosing

1300 Hz? Because we can lock onto a weak signal buried in noise twice as fast?

Because we can send and receive code twice as fast? We thought that was good

reason enough. Naturally, we would have loved to go even higher, but we had mercy

on your ears.

What does this mean? It means a typical CW ﬁlter will not work - will cause the DMX-40

to not work. Rather, set your rig to SSB. If you check in the PreppComm Community,

some have found adding a 1300 Hz ﬁlter helps, or their transceiver has the ability to

create a ﬁlter around 1300 Hz that is not too sharp and thus causing the decoder to fail

due to ﬁlter ringing, but most just use the SSB setting.

Essentially, if you are not tuning so the decoder is hearing 1300 Hz, the CW IN LED will

not light up, and nothing will decode. This can be quite a shock if you are not expecting

it, as you are used to decoding by hearing at just about any tone.

If you do a lot of CW, you are used to trying to isolate a single CW station so you can

'hear" only it, and thus decode it in your head. Here, it is quite different. You are

feeding a fairly wide audio signal to the DMX, and so it is doing the isolating via its very

narrow hearing ability around 1300 Hz. You can experiment with your ﬁlter settings if

you want to try to also isolate it for your hearing, but be careful not to tighten it up so

much that you cause ringing and decoder failure.

You also need to set up your transceiver so that it goes into transmit mode when the

KEY IN is activated. Otherwise, you will have to switch manually between transmit and

receive mode on your transceiver in addition to operating the DMX-40, which is, in a

word, not going to work for you. Full or partial breaking is ﬁne.

2. Decoder Only Use#

If you only plan to use the internal decoder, and not use the encoder, including the CALL

and ANSwer functions, automatic call sign capture, keyboard texting and type-ahead

buffer, and microprogramming for customization of operating methods, then all you

need to remember is to press the SPACE bar after tuning in the station of interest,

making sure ﬁrst that you are roughly in the center of the 1300 Hz bandpass of

approximately 100-150 Hz. The SPACE bar restarts the decoder by clearing the cache

of any information from previous signals. Also, while in decode mode, remember that

Page 18

the ESC key switches between HCW (human CW) and CTX (computer texting) modes.

You will want the HCW mode.

To operate:

1. turn on the DMX-40

2. Press the frequency button so it says External

3. Make sure you are in HCW Mode (HCW: Collecting Data...). The ESC switches

between HCW and CTX.

4. Start tuning around looking for stations to decode on your transceiver.

5. You will use your normal routine to transmit. Note it is a good idea to have a dummy

load on the antenna connector of the DMX-40 so it will not pick up your signal. If it

still picks up your signal, you have a serious issue with RF in your shack, and you

need to attend to that.

6. Don’t forget to press SPACE at the beginning of a NEW CODE STREAM.

3. Decode and Encode#

If you do the complete setup as shown in Figure 8 above, you will be able to use both

your key and the automatic keying functions of your DMX-40, as well as the

microprogramming functions for customizing your operation mode.

Please review Sections I and II of this Quick Start Guide. Section I explains basic

function, and Section II explains the various CALL and ANS functions for automatic

operation in transmit mode.

Once you have these bases covered and understood, you can "break in" with manual

keying at any time, and you can also train yourself for better timing by keying to the

decoder while in receive mode on the DMX-40.

Note that transmit mode on the DMX while in External Mode simply means it is focused

on transmitting CW to your rig, and receive mode means it is listening to your rig’s

receiver output. This means that you will be using function keys or the CALL and ANS

buttons to transmit, just as if you were operating in QRP mode. But instead, you are

transmitting at a much higher power via your external rig, and (one hopes) you have a

much better receiver feeding the decoder.

To operate,

1. Turn on the DMX-40.

2. Press the frequency button so it says External.

3. Make sure you are in HCW mode (HCW: Collecting Data...). ESC switches between

HCW and CTX.

4. Tune around the band looking for a spot to call CQ or for someone calling CQ, etc.

Page 19

5. Operate the DMX-40 transceiver as if it is the controller, and operate your external

transceiver as if it is merely a receiver and transmitter. In other words, you should

be operating the external receiver controls, but not the transmitter controls, which

should automatically engage when a key-down event occurs, and return to receive

mode either immediately when a key-up event occurs (full break-in) or after a brief

time (partial break-in).

That is a brief overview of setting up and operating your DMX-40. A more detailed

description of features and functions is provided in the DMX-40 Reference Manual,

which uses many internal links and an accessible from every page linked table of

contents to help you ﬁnd what you need to know. Also, make use of the PreppComm

Community. There are a lot of Q&A’s already there, and plenty of other DMX-40 users

out there who have asked the same question you have, or have answered someone’s

question. It is also a place to get answers from the factory.

Page 20

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