DX Commander 40m 3 element vertical array £299
NOTE: We're totally redesigning our business processes and also going on holiday. Shop will re-open end May 2019! We'll be back to normal then :) Hours of planning, modelling and experimentation both in software with MMANA and also real-world testing has finally produced an excellent and extremely economical method of producing excellent DX gain ...
Antenna Tow Ball Mount
NOTE: We're totally redesigning our business processes and also going on holiday. Shop will re-open end May 2019! We'll be back to normal then :) IMPORTANT NOTE: This is an experimental tow-ball mount. Under test, I achieved some extreme loading however I can take no responsibility for anything going wrong. Playing with portable antennas inevitable ...
DX Commander Bare Bones Complete 10m Multi-Band HF Vertical
NOTE: We're totally redesigning our business processes and also going on holiday. Shop will re-open end May 2019! We'll be back to normal then :) SEE LATEST DX Commander ABV Release Notes 2017 I listened! Some of you wanted an economical bare-bones system without all the little "bits". Here it is! Note: UHMWPE is suitable for world-wide ...
DX Commander all-band conversion kit
NOTE: We're totally redesigning our business processes and also going on holiday. Shop will re-open end May 2019! We'll be back to normal then :) This is the QRO conversion kit uses new UHMWPE plastic parts and 3mm pure Aluminium 1050 for improved efficiency. It's taken me a few years to get the dimensions ...
M0MCX Banana Antenna - an end-fed choke sleeve resonant feedline T2LT antenna design
A new document fully documenting the design of the Banana Antenna has now been released entitled, "Banana, a Half Wave End-Fed Choked Coax Antenna". Antenna can be known as - and is similar to: Sleeve Dipole / Flowerpot Antenna The Sleeve dipole has traditionally been used by VHF antenna designers by sliding an ...
JT65 UK Band Plan and how to stay within
The 5 MHz band is pretty cool and I've written about it before however out the box, JT65 allows you to very easily transmit out of band on 60m band. The segment we're interested in the UK is the freq block between 5.354 and 5.358. This has taken me a little ...
Introduction to the 60m Band Plan (5 MHz)
60m is an interesting band. it's partly channelised into small segments and the propagation is a cross-breed of 40m and 80m.The band was first introduced apparently in 2002. Over the years, various countries have allowed their amateurs radio operators to use the band. All this is negotiated and approved in conjunction ...
Working 15m band on a 40m vertical antenna
Note: This article discusses the merits of a 3/4 (three quarter wave) vertical -vs- a 1/4 (quarter wave) antenna. You can build a 40m vertical quarter wave antenna and ground mount it with 16 x 4m radials and operate it at the third harmonic; 21MHz. Actually, all my experimentation has shown that ...
Converting a 40m vertical to run on 80m / 75m band
Recently, I created a slightly loaded 40m vertical with 25 ground radials. It seems to work very well although the receive noise is pretty lousy compared to my loops and dipoles, however on transmit, it does seem to work as planned; a typical 1/4 wave pattern that outperforms regular dipoles at low angles of ...
Raising Steel Antenna Mast on T&K brackets with pulley
I'm gradually swapping out any aluminium antenna poles for steel. Clearly these are very heavy, particularly with an antenna on top. The trick is to use V bolts (like U clamps but in a V shape) and not to use saddle clamps because the pole will not slide easily past the ...
How to make a stealth amateur radio wire antenna
Until recently, I had a) a 40m triangular loop in the back garden which I called a "micro-mega-loop" and b) a 60m loaded loop that allowed me to get on 80m. The two loops looked a bit horrendous not only because of the wire in the air, but because I ...
Special Event Operating Procedures
This note will be particularly beneficial to those who may be required to run a special event station either on the lower bands or maybe on VHF. These tips & tricks will also help you anywhere on the band, regardless of your circumstances. Preface: There are a number of aspects that ...Lorem Ipsum is simply dummy text of the printing and typesetting industry.
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- DOWNLOAD m0mcx sample contest logbook
Confused? See the film here:
This is a ZIP file. Obviously take necessary precautions when unzipping etc. I’ve had this installed for about 2-months.
NOTE: It’s a self executing program file. It doesn’t need DLLs and doesn’t “install” itself in Windows. It just runs from the install directory and you can move it around, say on a USB stick if you like.
Here’s the spreadsheet:
EXCEL: <quarter wave vertical calculator> link
Here’s me on 15m during IOTA 2017:
(100 Watts, recorded straight out the TS590SG into Audacity)
Antenna: DX Commander Vertical 80m-10m
Compare Red 5/8th -vs- Blue W/wave
Anyone who has mucked about with verticals will no doubt have worked out that a full-sized quarter-wave for the 40m band, more or less tunes up for 15m band.
It wasn’t until my entry in IOTA Contest this year that I convinced myself that they are not a cloudburner (as many people suggest) but compare favorably with a quarter-wave, even producing more gain by 2 dB at 10 degrees above the horizon.
OK, so 2 dB isn’t a huge gain, but hey – it’s free. Take it when you can!
Don’t forget, you can do the same for 10m band too by making an element 6.83m long and folding it back a further 1.11m (for 28.5 MHz). So you’ll need nearly 8m of wire. Don’t forget, that’s insulated wire!
If you’re into MMANA software modeling, here’s the file:
NOTE: This is a ZIP file because my Content Management System doesn’t like files ending in MMA. By all means have your Virus Scanner check this Zip file. There is only one file inside this ZIP. Just the MMANA file.
You only need to type in the numbers in the Cyan boxes.
- For Dipoles: Cut / Add the result to each leg
- For Verticals: Cut / Add result to your vertical radiator
Just type in where it is resonant right now – then type in where you would like it to be resonant and the spreadsheet will auto-calculate the trimming.
Film: How to use the SWR Adjustment calculator.
The previous owner (retired communications and instrumentation technician for a large, multi-national organisation) replaced both fans with ultra low noise “Arctic” fluid bearing units. These are installed in 2 speed via voltage regulation manner: Low speed during stand-by (RX) and High speed during TX. (read more…)
My own issue is that I needed just one antenna that would deliver an all-band solution, certainly for the contest bands of 40m, 20m, 15m and 10m – but I also needed 80m in the mix too.
My holiday home has a very compact small garden so the option of putting up a dipole for 80m is out the question, but modelling suggested than exchanging the 30m element for an inverted L for 80m should work.
The 80m element therefore starts vertical, like all DX Commander elements and turns a sharp corner at 6.9m above ground and droops down for around 13m or so, hanging over a bush at around 3m off the ground. Probably not perfect but perfectly adequate to score 44 QSOs inside an hour on the Saturday eve of the IOTA contest. That score includes 16 different IOTA multipliers, certainly a wide spread around Europe.