ALL BAND LISTENING GUIDE
I just spotted something of interest to QRP operators. I’m not sure how successful it’s going to be, but I do believe it has some mileage and I’ll certainly be adding my support to the idea.
Visit G4ALG’s website for more information.
73, Tom, M7MCQ.
QUICK >>UK<< REVIEW
OF PREPPCOMM MMX
It's always bothered me that I can’t work CW - I find it very appealing and recognise its ability to potentially reach much further than SSB. Even in poor band conditions, CW Operators seem to be able to have QSO’s. But what can I do?? I’m too old and too damned busy to learn a new language.
I borrowed a Morse Tutor and Key and I tried my heart out for a while, but soon realised that it was going to take me many, many months to reach the point where I could call myself proficient - and that means many months of not doing something else with my leisure time.
Traditionally, decoders/encoders have been very poor performers. A few companies have manufactured Morse Code Readers/Keyers such as MFJ with their 464 model, but reviews of this and other similar devices are not very complimentary at all 😢
Machine decoding of Morse is not easy. Some people think of CW as ‘digital’ because of its ON/OFF nature, but of course it is very much analogue. Apart from the on/off element, there’s also the shape of Dits and Dahs and the oh so important spacing between them and the spacing between the letters and between the words.
Human beings cannot send perfectly timed and spaced morse code, but thankfully, they don’t need to, because the human on the receiving end has a brain which is powerful enough to cope with the variances - a machine can’t!
So all was lost! Then I heard about the PREPPCOMM DMX-40...
The DMX-40 SDR Morse Decoder & Encoder Transceiver (designed and built in Idaho, USA by Eric Anderson and his team) is a standalone, portable single band (40M) SDR QRP device which allows users to decode morse signals and it also allows you to transmit morse code by simply typing your message on the supplied keyboard with up to 3W output.
Now, similar claims have been made in the past and some manufacturers have got closer than others in achieving this holy grail, but according to an American reviewer, the PreppComm actually works - almost every time!!
That is great news and it will be of considerable interest to many people out there who want to join in the fun of CW and benefit from its long reach. The DMX-40 has a CW receiver which is said to match some of those on more expensive radios. Thanks to its high-noise immunity decoder, it has superb sensitivity and selectivity and decodes text even when the band is very noisy and busy with people transmitting very close to one another.
One of the most appealing features of this transceiver is that it's compact and portable and will be a fantastic aid in SOTA & POTA operations. Unfortunately, you have to use the supplied keyboard - you can't just use any old USB keyboard, but thankfully, the supplied unit is light and will fit into your go-bag with ease. I managed to find an alternative on Amazon called the SR Mini Keyboard as a backup.
The 3.5" colour-screen is a Touch Screen, making operation very simple and intuitive. There are 28 menu screens in total, including a built-in Help Section - that's always good to have when you're out in the field and you've forgotten how to use a particular feature.
In addition to being a self-contained 3W CW Transceiver, you can also connect the device to your existing radio and (in theory) use it to decode/transmit CW on any of the bands that your radio has - including VHF/UHF. That would be amazing!
Finally, this device could become your active (and passive) morse tutor. You can attach a key and practice as much as you like and instantly see the results on screen. Currently, you can only use a straight key, but hopefully, there'll be a firmware update in the future which allows paddles.
PreppComm is a small company, but the benefit of that is that you feel like you can relate to them and it's both interesting and amusing to read through their Development Blog and learn about the trials and tribulations of getting an idea to a working product. One part of the Blog relates to installing SMD components on PCBs and boy, I think everyone in ham radio can symapthise, LOL.
I purchased my PreppComm directly from America and due to chip shortages, it took a loooong time to arrive in the UK. I was then hit with import duties and to be honest, had a bit of a nightmare with the courier.
On opening the parcel, you will find (depending on what you ordered) the radio, a protective lid, a compact keyboard, a power adapter, cable-set, a pair of 'legs' and a screen cleaning cloth.
The thin legs which came with the MMX were not very practical as far as I was concerned, so I replaced them with a pair of slimline Laptop Stands from Amazon. These are permanently attached to the base of the rig and fold away neatly when not in use.
Before using the MMX, you should take a few precautions. Don't rush into things like you might do with a regular radio - this isn't a regular radio! You really do need to read the manual or you may end up pulling your hair out and even worse, damaging the rig.
Here's what I suggest you have to hand...
STANDALONE (QRP) MODE or EXTERNAL
When you're starting out, you need to make sure you're in External Mode - this turns off the receiver and transmitter, preventing accidental transmissions. While in this mode, you can practise all the operations detailed in the manual. Since the transmitter is disabled, you needn't fear rookie mistakes - it's your Safe Mode!
Once you feel that you understand your way around the MMX, it's time to remove the Dummy Load, connect an antenna (preferably a resonant one - check the SWR) and switch to Standalone Mode by selecting a band/frequency.
Standalone Mode (sometimes called Companion Mode) allows you to receive and transmit, so take your time and have the User Guide to hand. Pretty soon you'll be tuning in CW signals and will see the decoded message onscreen. The MMX is pretty amazing at decoding - even in noisy conditions and you'll soon have a smile on your face 😊
When someone calls CQ, the radio is usually able to detect the sender's CallSign and it's very easy to respond. You simply press the ANS button and your radio will begin to reply with your CallSign and let you type your message to the caller. Don’t forget to press ANS after you’ve finished typing, or you won’t receive anything back.
If your transmission is heard by the other station, you'll see his/her response and you can continue with your QSO. There are a number of Macro Memories for the messages which one sends routinely such as "Your report 599" or "Thx for QSO, 73 M7MCQ", etc, etc.
Rather than responding to someone else's CQ, why not call CQ yourself? Simply press the onscreen CALL button and the radio will start the sequence. It will repeat the call until you press CALL again or press ESC on your keyboard.
The PreppComm has no tuning dial, so you'll need to use the onscreen arrow-keys to navigate the band. It feels odd at first, but you soon get used to it. Just remember though, accurate decoding will not begin until you initialise it by pressing the spacebar on your keyboard. Do this every time you retune the receiver. (READ THE MANUAL).
Using the PreppComm as a standalone unit is the simplest method of operation and you'll have lots of fun with it at home or out in the field. It's small enough and light enough to throw in a go-bag with a wire antenna and take with you on a walk - just don't forget the keyboard (as I once did, lol).
TIP : When you start out experimenting in Standalone Mode with your new PreppComm, do yourself a favour and optimise the chances of success by operating on a day when the bands are buzzing with signals and operate from a location with a good take-off. Better still, find a good CW operator who is willing to send and receive with you while you learn the operating process - priceless!
And don't forget that when you think the radio isn't decoding properly, it may well be a poor operator who's simply not very good. They are out there 😆, so QSY.
Remember that you're operating at QRP levels here (3W) and if you're not used to that, you could get frustrated. Avoid trying to break through pileups - try calling CQ instead. Spot yourself on sites that allow it - that always helps.
CONNECTING TO ANOTHER TRANSCEIVER
(External Mode)
You can see in the photo above that I've used a 12V PowerBank and connected to it to the MMX using a USB 5V to 12V Lead which has built-in current limitation to protect the finals. A worthwhile optional purchase!
As shown in the previous diagram, setting up your radio is pretty simple and logical, but getting good decodes from your PreppComm is a little more tricky and confusing.
The confusion is pretty much down to the very odd 1300Hz tone which PreppComm use. Most CW tones (pitch) are set around 600, so why did Eric choose 1300Hz??
Well (for reasons beyond my understanding) it makes it easier for his machine to decode reliably - even in noisy parts of the bands.
LETS RECAP on what’s going on…
At this point though, the PreppComm CANNOT HEAR IT!
Your CW Pitch is set at 900Hz and the PreppComm is listening at 1300Hz, so you need to tune a little higher up (400Hz (the red line)) and boom, the PreppComm will start to decode!
But because you’ve moved your transceiver away from the actual signal, if you now transmit, you’ll be 400Hz away from the sender and he won’t hear you. That’s why we use the RIT feature.
RIT allows you to LISTEN on one frequency but TRANSMIT on another. So you’re tuning into 7.035MHz for transmitting but actually receiving on 7.039MHz.
I hope that helps to make it clear. Without an understanding of that, you could end up struggling and unfairly blaming the PreppComm for failing to decode as advertised.
So, back to the PreppComm’s performance...
After you have spent time reading the manual and getting a grip of the tuning and general operation, you will soon start to enjoy the device. It works well and is a very welcome addition to the shack (and rucksack).
I noticed something odd last night though - while tuned to 7.030MHz, I could hear feint foreign voices in the background which then changed to music - it was a broadcast station! I switched the antenna over to my IC-705 to see if I could still hear it but I couldn't - presumably because the 705 has much better filtering. I'm pleased to report that it didn't effect the MMX's ability to decode the cw signal - which in itself is a good indicator of the decoder's ability to ignore unwanted noise.
In Standalone Mode, I think the DMX/MMX receivers are probably better suited to outdoor operations than indoors. If you're doing a SOTA or POTA operation, with low ambient noise levels and a decent antenna the PreppComm will absolutely thrive! 3W is more than ample to get Transatlantic contacts.
Back home in urban or suburban areas, where conditions can be far more challenging, I believe it makes much more sense to use the PreppComm in External Mode connected to your Base Station - again it will thrive!
There's lots of fun to be had with this device and once you understand how to operate it, your previously 'cw-void' logbook is going to start to fill up with new contacts. Sure, there's a learning curve - not only the operation of the device but also the cw etiquette and procedures, but it's all worthwhile.
Would I recommend buying one? Yes! Absolutely!! Especially now that a UK Distributor will be available 👍
Which model should you buy? For those wishing to work with the PreppComm as a standalone, then I'd choose the MMX.
Who else might be suited to one? I am personally aware of at least two CW operators who have developed conditions as they've grown older that have left them with shaky hands. Having a PreppComm could potentially allow them to continue enjoying their beloved hobby.
POSITIVES :
FANLESS MINI-PC FOR THE SHACK
My main PC is a gaming machine designed to cope with the insatiable demands of modern Flight Simulations and I decided to move it to a spare room where there's space for all the associated paraphernalia like throttle, stick, rudders, big screen, etc.
In it's place, I put a Laptop in the shack but I really disliked how it took up so much desk space and offered little in the way of display screen, plus it pelted out a fair old amount of fan noise from a side vent. So I had to find a better solution!
Looking around I found some MINI PC's on our local shop's website and was intrigued by their compact size and the fact that they were fanless.
As much as I liked the idea of one of these tiny, silent PC's, I didn't much like the prices - yikes! So I figured there might be some on the second-hand market and started to search eBay for one. There weren't many up for sale and the prices were still a bit on the choppy side.
I then looked on Facebook MarketPlace and spotted someone local selling a mini PC that was small but not quite as tiny as the ones I'd been looking at. Worth a look though, so I went to the seller's house.
It was a very compact and fanless PC with an Intel i7 CPU running at 1.8GHz which should be fast enough for any of the radio-based software I'd be running. It also had 16Gb of DDR4 RAM which seemed very generous compared to some of the offerings on Scan's Website.
The unit had a 250Gb M.2 SSD which again, was ample for my requirements. It even had a built-in Wi-Fi Router and room inside the case for another drive and extra memory. It was installed with Windows 10 PRO and came with a mouse and keyboard.
EDIT : 26 Feb : A friend had a brand new, boxed 250Gb M.2 SSD and sold it to me for £20, so the storage space has now been doubled!
The guy showed me he'd paid £500 and was only asking £300 for it which seemed reasonable, so I bought it. Result!
Once I'd installed it in the shack it was time to load some software and see how it performed with my most often used programs such as ELAD FDM SW2, SDR UNO and EXPERT ELECTRONICS SDR2. These can be quite demanding, so I needed to know if the PC was capable of coping without any stuttering and without me having to fuss over the operation.
I noted that although the processor's base speed is 1.8GHz, it appears to be running at over 3 GHz and every test went well. Using my main shack radio (ELAD FDM DUO) and the SW2 software, there were no operational problems whatsoever - even when I had 4 receivers running. I could also open QRZ to access my logbook without any hint of choppiness.
There was a brief episode of locked mouse-cursor and I couldn't figure out why, but then I discovered it was because I'd inserted a 128Gb Micro SD Card which it didn't like much. As soon as I removed it, everything went back to normal.
As for temperatures, yes, those cooling fins get quite hot when it's running multiple receivers on a 2K screen (2560x1440) but I use a neat app called CORE TEMP which not only monitors the temperatures of each CPU core, but takes action if things got too hot by putting the computer into sleep mode until things cool down. I've tried my best to overcook the processor by running multiple demanding programs, but it doesn't seem to phase it. Sure, temps get quite high in those circumstances and things go from green to amber, but no red - so far.
So basically, this little gem is perfectly capable of running any of the SDR software that I use and more! It's capable of running three monitors too but to be honest, a 2560 x 1400 desktop is plenty big enough to have multiple windows open such as WSJT-X, GRIDTRACKER and SDR software.
£300 for all this?? That'll do! 😍
Video-Clip of the Mini-PC running ELAD FDM SW2 software...
73, Tom M7MCQ.
Over the years I've had countless conversations with people who almost mockingly ask about my hobbies. And I'm not just talking about strangers - friends and family can be guilty of it too!
I used to try and justify why I had hobbies, but in more recent years I just stopped trying and I'd change the conversation away from me and my apparently "strange and anti-social ways".
I must admit I do have a lot of hobbies - perhaps more than most...
Well, as you can see, I keep myself pretty busy with one thing or another. I do my best not to become obsessive about one particular hobby and regularly move from one to the other. Because amateur radio has so many facets to it and is ever-changing, I probably spend most of my leisure time messing with radio one way or another.
Anyway, back to the reason WHY?
I have never quite understood why hobbies have attracted me so greatly. When most other people get some leisure time, they sit back, watch TV, go to the pub or scroll their life away on their iPhone.
I just can't do that! All my adult life I've had this "feeling" that time is running out and I should be doing something worthwhile - something constructive - something creative. Making something! Making something happen!
Is that odd? I really don't know. Maybe it's because my father died when he was just 27 years old. I used to worry about reaching that age and following suit, lol. And then when I had my first child, he too died young (15) so that probably reinforced the idea that I need to crack on with something. Of course having a terminally ill child means that you spend those years meeting other families with terminally ill children, further strengthening this feeling.
As I've got older and "climbed the ladder" at work, I've been under more and more stress. I am now the Operations Director at a small company and that basically means that I'm responsible for everything! I have to succeed in every task - which is not always possible - or it takes much longer than you'd like due to having to learn new skills. The pressure can be intense and there are often failures before success comes along!
And this is where I discovered the answer to the question "Why do I have so many hobbies"?
Success! Hobbies can provide success. As daft as it sounds, that only dawned on me a couple of weeks ago. I'd had a particularly stressful week at work and was feeling drained by the end of it. Over the weekend I decided to build a V-POLE using a couple of cheap telescopic whips I'd purchased from China.
Almost without you realising, these small successes can provide much needed healing and can counter the damaging effects of stress. Sure, some of my hobbies drive me around the bend with their technical complexity, but unlike work, they're voluntary and I can always walk away or seek help from smarter people.
So now, when someone asks me about my 'geeky hobbies', I have an answer that makes them realise that they're missing out.
Enjoy your hobbies - they're good for you. Ignore the ignorant!
73, Tom, M7MCQ.
RuckShack!
Ooow, I invented a new word 😂
It's been very flexible in terms of what can be secured in there. The padded dividers can be configured to fit virtually any item thanks to their Velcro fixings and because there's more than you usually need, you can use spare dividers as covers to prevent stuff falling out when you open the rucksack.
This particular model is the Lowepro LP36892-PWW Tahoe 150 and only costs £60 on Amazon, but I actually paid £40 for mine as a second hand item on Ebay. It was in perfect, as-new condition!. It's had a few years of use and abuse now, but it's proved to be tough as old boots.
And then lo and behold, I spotted another minter on Facebook MarketPlace yesterday for £30, so I snapped that up too. The guy only lived 4 miles away, so that meant I could check it out before paying.
It also stores my SotaBeams/Hawkins antennas in the front cover along with a pencil and notepad. On the side of the rucksack it has a net pocket which holds my telescoping mast and has a quick release strap higher up to keep it stable.
Having found another of these versatile carriers (at a bargain price), I can make up a second 'RuckShack' ready to go, instead of swapping out radios and rearranging the dividers every time.
Highly recommended product!
73, Tom, M7MCQ.
#ruckshack #lowepro #sota #sotabeams #elecraft #icom #pota #camera-bag
By Rob Ramsey, AH6X
I recently purchased and received an Elecraft AX1 antenna. Since then, I’ve tested it and made two significant modifications that I found helpful and wished to share.
Though the stock antenna configuration works as advertised, through experimentation, I have discovered it is possible to make it resonant on 10, 12, 15, 17, or 20m.
Elecraft markets the AX1 as a field expedient antenna that supports operation on the 15, 17, and 20m bands with a tuner. Some tradeoffs were made as packaged: a single 13ft radial, the 46.25in whip, and a 20m/17m switched coil assembly. The stock configuration lives up to its branding and delivers an experience proportional to its compromises. However, more is possible.
The AX1’s vertical element is too short to be resonant on 20m. This limitation can be overcome by adding additional coil or by using a slightly longer whip antenna.
The single radial is a similar situation; with a 13ft length, it’s not resonant on any specific amateur band. A multi-element radial could be used with resonant lengths for each of the desired operating bands. These trade-offs were probably made for a variety of reasons.
First, using this antenna in a resonant multi-band configuration requires an antenna analyzer to tune the whip length properly.
Second, using a longer whip and multi-element radial would increase the cost.
Third, a longer whip and multi-element radial weighs more and would take up more room than the stock parts.
Fourth, a longer whip is less stable when mounted to a small tripod or the radio.
Lastly, tuning the antenna and fanning the radials out would take longer than the original deployment strategy, diminishing the antenna’s field expediency.
The multi-element radial has been cut per the standard calculations (see charts at bottom of post), and the adaptor allows me to connect any 3/8-24 threaded whip to the 4mm x 0.70 threaded coil assembly.
The BuddiPole product line has a large variety of telescoping whips. For this project, I used their Featherweight whip, which extends to 72in (6ft) and collapses down to 13in. With it, the antenna can be easily tuned by collapsing or extending the telescoping whip.
For the multi-element radial, I used Super Antenna MS135 SuperWire with a 14-16 AWG spade connector and some heat shrink tubing. For storage, I wrap the radial around a SOTABeams wire-winder.
This custom configuration allows for a 3:1 SWR in the 10, 12, 15, 17, and 20m bands. Overall, I really like the Elecraft AX1 antenna. It’s a good product, made resonant, with just a few adjustments. See images below.
I also made a "tool roll". My mother-in-law showed me how to sew a wrench roll for my Elecraft AX1 antenna. I use a similar setup for my Super Antenna. The fabric is light, protects the parts, and makes antenna transport easy.
Let me know what you think in the comments. Thanks in advance!
Rob, DE AH6X.
Many thanks for your contribution to the Blog Rob!
A very interesting read. I love this sort of stuff.
Tom, M7MCQ.
ELECRAFT'S BEST KEPT SECRET?
A case in point was when I needed to calibrate my PreppComm MMX and had to burden my friend Chris at Cross Country Wireless with the task.
Enter the Elecraft XG3! It certainly addresses two of the issues - size and complexity, but they're still on the expensive side at $300 😮
With the free downloadable software, you can program the XG3 to act as a Beacon, repeatedly sending a message - ideal for Fox Hunts or RBN tests. I couldn't quite figure out the syntax of the programming language, so I emailed Elecraft Support and the came back immediately with a great response. I now have "CQ TEST CQ TEST M7MCQ M7MCQ" set in Memory #1.
Most of the time though, you'd be using it to test radio equipment and to assist you with that, it has a number of useful presets.
The RF output has 4 presets ranging from -107dBm through to 0dBm and includes a -73 setting which is particularly handy for testing the accuracy of your S-Meters, since -73dBM is equivalent to S9.
There are 12 Band Settings from 160M to 2M. These are preset to certain frequencies but you can adjust these using the computer software mentioned previously. You can change these frequencies to anything ranging from 1.5 to 1400MHz but great accuracy is only guaranteed below 200MHz. Anything above that relies on the harmonics of the fundamental of the RF signal.
On the top of the XG3 case is an input for an external power supply, a PC programming port and the RF-Out connector which is BNC. At the rear of the case is a battery tray to carry the 9V PP3 battery. Thankfully, the unit has reverse-polarity protection, because it's oh so easy to put it in wrong 😳
So there you have it. A very nice addition to the shack at a great saving on the new price. I'm quite sure this will be a very handy unit to have around for me and my radio buddies.
73, Tom, M7MCQ.
WM,[15}CQ_TEST_CQ_TEST_M7MCQ_M7MCQ;PF,01,01;
