PreppComm MMX Multi-band Morse Code Transceiver
PreppComm MMX Multi-band Morse Code Transceiver
PreppComm MMX Multi-band Morse Code Transceiver
PreppComm MMX Multi-band Morse Code Transceiver
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EU? Order from WiMo! See note below

Multi-Band QRP Portable Computer Plus Transceiver!

Check out the MMX Bundles below!

The MMX Multi-band Morse Code Transceiver is the evolution of the DMX-40 Morse Code Transceiver,and includes the keyboard and a small pair of wired earbuds!  It has the same industry-leading decoder, the same high sensitive SDR receiver, 10 frequency memories per band, RPL microprogramming for custom automation, and more.  However, what is added is a band board plug-in system that supports up to 3 bands.  Currently, the supported bands include 80, 40, and 20 meters.  You can purchase a single band MMX, and add other bands later, purchase a dual band MMX, and add the third band later, or even get all three bands on your initial order!

Specifications are similar to the DMX-40+, such as receiver sensitivity of -119 dBm.  Power output is highest on 40 meter, and slightly lower on 80 and 20 meter bands, as listed in the Specifications tab in the right column.


A version of the MMX is available that is JUST for using with an existing station.  No QRP transceiver inside. It's called the MMX-ZERO, or ZERO.  Check it out!

Better, Easier, Relaxing QSO's at Higher Speeds!

Do you need help decoding those fast senders?  Do you want a less stressful QSO?  Not only do we help you decode with the best decoder in the industry, but you will gradually learn to do so as well by way of cognitive association!  For sending, you can use a straight key, the built-in keyboard to Morse system with automatic station ID's and hand-offs, auto-CQ and station calls, automatic capture of the other station's call sign, plus the powerful RPL language for microprogramming to customize of the automation or create your own automations.  And, you can get help and practice sending using the build-in decoder to listen to your keying in receive mode.  It will treat you as "just another station" and decode your signal, give you your speed, and tell you what other stations would think you had sent.  Great key training!  And don't forget to start by pressing the Space Bar to restart the decoder before you begin keying!.

Another stress reducer!  The built-in typing speed test function sets your maximum transmit speed to match your typing speed!  This means that - even if the other guy can type or send at 35 WPM, but you can only type at 22 WPM, that is how fast you will go, enabling you to have time to partially fill the type-ahead buffer so you can relax and edit your keyboard mistakes, and have a little time to think about what you want to say next. A great stress reducer. Of course if the other station is sending at a lower speed, your MMX will match them so they can decode you!

Talk about stress reducing, the automatic capture of the other station's call sign is a great one!  It automatically appears in the CCS button (CCS is Captured Call Sign), and is used for the automatic station ID's and hand-offs.  No more quick scribbling to write down their call sign!  Or typing station ID's over and over.  Even a Handle, QTH, Rig, Antenna macro built-in so you can send that info with a single keystroke!

If you want to use a paddle or iambic key, an external keyer is required to convert your key to straight key or "pure Morse" output to feed into the MMX.

So, up your game!  Get an MMX to go with you for a great experience in QRP with a lightweight powerful computer plus QRP transceiver!  Great for POTA, SOTA, etc.  Or, get an MMX attached to your station using our External Transceiver Cable Assembly to make it easy and neat to connect and integrate your station and the MMX as your decoder and encoder.  You can also just use the MMX as a decoder, with no keyboard by pressing the status line to restart the decoder

Videos And More Info!

There is lots more features:  check out our main features on the Features tab in the right panel, and our More Features list!   

You can Download Data Sheet here.

Below are two video links.  The first is a long open box to QSO live demo via Coffee and Ham Radio on YouTube.  Note that the MMX is accidentally placed into CTX mode during much of the session (and thus can't decode human code, or HCW).  I finally noticed that, and after that, things went a lot better!

MMX Live Demo 

Since the MMX is just a DMX-40 with band cards, the DMX-40 videos are very helpful and on-target for learning about the MMX:

DMX-40 Videos

And here is a look inside the MMX.  Note:  What comes with the MMX is misrepresented in this video.  Only the keyboard, cleaning cloth, and power adaptor come with the MMX, but otherwise, pretty accurate:

Also, for more information, read the DMX-40 description. The MMX has all the same functions and features, but 3 band capability!

What's Inside the MMX

The MMX Bundles

To make it easier to purchase the MMX, we offer 4 bundles:

  1. The MMX Bundle: this includes a stand, dummy load, cable adaptor, and cable assembly
  2. The MMX Complete Bundle: to #1 above, we add a powered speaker, A/C USB power block, 5V to 12V cable, audio cable, and USB cable for a truly complete setup
  3. The MMX EMP Bundle: To #1 above we add an EMP Shield zip-lock, a roll-up keyboard and cable, and an interior canvas bag for the MMX to protect the EMP Shield from sharp corners on the MMX
  4. The MMX Complete EMP Bundle: To #2 above we add an EMP Shield zip-lock, a roll-up keyboard and cable, and an interior canvas bag for the MMX to protect the EMP Shield from sharp corners on the MMX. We also add a second EMP Shield bag to protect the speaker, USB Power Block, and 5V-12V cable, all of which have sensitive electronics within them


International Orders

For all MMX orders for EU delivery, please contact our EU distributor:

WiMo Antennen und Elektronik GmbH * Am Gaexwald 14 * 76863 Herxheim, Germany * Tel: (+49) 7276 96680 *

Otherwise, be aware that by purchasing a product from the USA will require going through customs in your country, and typically you may be required to pay duty on your order. Check with your local authorities for details. Also note that if your country uses the VAT tax system, VAT taxes will also apply. Finally, UPS also typically charges a fee for handling the collection of duties and taxes. USPS does not, but their shipments take longer.

MMX Multi-band Morse Code Transceiver

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The MMX Morse Code Transceiver is a new product, so we do not have any user comments yet.
  • Finally, the true power of the DMX-40 GUI and programming released by a multi-band, card caged transceiver motherboard!
  • Same amazing feature set as DMX-40, but now with multiple bands!
  • Simple GUI for multi-band operation.  The Frequency Button is also the Band button!
  • Unparalleled Decoder Capability in Noisy Environments:  With its unique signal processing algorithms, the Morse Code decoder outperforms all others.
  • Type and Read in English:  Use the included QWERTY keyboard to type, while hearing outgoing and in incoming Morse Code, aiding in learning the code subconsciously.
  • (Optional) Learn Morse Code:  The included Morse Code Key-In capability with built-in decoder testing aids in learning the Code.
  • Automated Send/Receive Protocols:  Enter your call sign and other information for station setup.  Remote station call sign captures automatically.  All call and answer protocols are automatic – you only type your message.  Or change the protocol via built-in micro-program editor.
  • Set your maximum comfortable typing speed:  While the MMX can send very fast, it’s best to limit speed so you don’t starve the transmitter.  A unique feature that maximizes the use of the type-ahead buffer in transmit mode calculates your comfortable typing speed automatically.
  • Super Power Micro-programming System:  Besides simple automating common text segments, the micro-programming system allows control over the transmitter, enabling many advanced features.  12 micro-programs up to 60 characters each.


Click Here for a Complete Features List

  • Multi-band:  up to three bands supported via a three-slot card cage on the motherboard.  Auto-sensing and auto-selecting via sense/select hardware on the motherboard  - any slot for any plug-in band board.  Use the Frequency button on the Main screen to select which band card to use.  Currently available bands are detected automatically and offered via the Frequency button.  80, 40, and 20 meter band boards are currently available.
  • Advanced Direct Conversion SDR Receiver: with custom filter, balanced mixer, and low-noise preamp giving sensitivity 0.3µV, -118 dBm or better
  • GUI: 3.5″ color touchscreen LCD
  • Weight: 11 oz with protective lid
  • Size: 3.8″ x 5.2″ x (1.3″ w/o lid, 2.25″ w/lid)
  • Power Consumption, receive:  1.4/0.96 watt, LCD backlight ON/OFF
  • 80 meter band:  3.5 MHz - 4.0 MHz. SWL range: 2.45 - 5.6 MHz
  • 40 meter band:  7.0 MHz - 7.3 MHz. SWL range: 4.9 MHz - 10.22 MHz
  • 20 meter band:  14 MHz - 14.35 MHz.  SWL range: 9.8 MHz - 20.09 MHz
  • 80M Power Output @ 13.8V:  approx. 2 W, 350 ma (key down)
  • 40M Power Output @ 13.8V:  approx. 3 W, 500 ma (key down)
  • 20M Power Output @ 13.8V: approx. 1.5W, 350 ma (key down)
  • Key up power @ 13.8V: approx. 110 ma, 1.5 watts (LCD ON)


The MMX Morse Code Transceiver combines a state-of-the-art decoder, a color touchscreen graphical user interface (GUI), a Software-Defined Receiver (SDR) and a QRP (Low Power) transmitter, all powered off of a 12V power source, packed into a small, lightweight and very portable package. The decoder uses innovative digital and analog signal processing circuitry and algorithms to overcome the typical noise found in most real band operating conditions.GUI for countless features

The GUI includes a full menu system, and 28 unique graphic screens to accomplish an amazing set of features, some not found in transceivers at any price.  SDR receiver sensitivity is -118 dBm.


Automated functioning

Computer automation simplifies the process of calling and interacting with automated station ID’s and remote station call sign capture. The built-in automation can be user-modified using the powerful microprogramming language RPL (Rig Programming Language), with unique capabilities.


Multi-Band via Plug-in Band Boards

The MMX includes three plug-in slots for band boards.  From 1 to 3 bands can be directly supported.  Currently available:  80, 40, and 20 meter band cards.


Operate on any band

Operating modes include normal transceiver mode and the unique External Mode, which allows operation with an external transceiver. Using this feature, operation an any band with the full decode and encode function, including automation, is possible.

Customer Reviews

Based on 8 reviews
John Reinke

I am very pleased with my MMX-ZERO and use it with my Icom 7300 and X6100.
I purchased the MMX-ZERO plus all cables to make the setup easier which it did.
Within ten minutes of setup I had my first QSO . Fantastic
Its a great learning tool and Highly recommended.
Make sure you view the videos first, which will make things easy.
I love using my MMX-ZERO.
Thanks Eric and the team at PreppComm
Whats next Eric ?
73 John ZL3QRP

Thanks for your wonderful review, John! We could tell you what's next, but then we would have to send the black helicopter... :) I am sure you will love it!

David Lyons
An outstanding product.

I am extremely pleased With the MMX 20/40 and Preppcomm tech support.
The MMX 20/40 is easy to set up in both Stand alone mode, and external mode ( using the accessory cable set they offer) with my FTdx10. I made my first QSO two hours after setup and learning the ropes by reading the manual and experimenting using a dummy load. I logged 8 contacts before the day was out.( two of those DX).
Tech support is excellent. Twice I emailed Eric Anderson with questions . He got back with answers within 30 minutes both times.
The MMX 20/40 provided me with the impetus I needed to learn CW. Learning Morse Code is something I had shied away from but always wanted to do. Using the MMX has got me fired up! I started online Morse code training. I also bought a paddle key for use on my FTdx10 and I am progressing with that at a good pace.
( The MMX takes a straight key only. Perhaps newer versions of the MMX will have an electronic keyer built in or offered as a designed for MMX accessory? ) The MMX allows me to enjoy the mode while I learn. I find watching the text and listening to the code helps me learn both the code, and the abbreviations and pro-signs.
I can't wait to see what Preppcom comes up with next.
David KD2UBX

Bob Woods
Amazed old ham!!

First licensed W7IUT in 1953---CW is my lifetime choice---not a hotshot my max about 20 wpm tx & rx--but the MMX 80/40/20 after only a few days of getting familiar is a real pleasure---it performs exactly as advertised, is intuitive in setup and seems to be very kind to my shaky old fist and straight key. I will continue with making friends with this wonderful little box. Eric and colleagues are to be congratulated on creativity and innovative thinking ahead. The MMX has the potential to restore what I feel is still the most useful long distance communicator---CW! Bob W7iut

Thanks, Bob! It is always encouraging to get reports from the field. Most people don't take the time to review products, so we appreciate your review!

michele yikints(Mickey)
Alternative to traditional CW

I am a new Ham (year old) . Short while ago i got interested in CW, as i was struggling to learn Morse code a friend of mine gave me the link to PreppComm and the rest is history.
last week i introduced my MMX at the monthly club meeting , we set 3 CW stations and worked 20M. for half hour in external mode.
It was a big hit and i was very glad to share it with fellow Hams.
In summary:
Great alternative and learning CW tool .
Exceptional online support with reference material.
And much more
Thank you PreppComm.

Alvin Norris
My new CW QRP radio

Thanks preppcomm!
I’m a Know Code Extra that needs to do a little brushing up on my code speed. The MMX is just what I needed.

Let us all know how it works for you brushing up!