Amateur Radio

Phasing Harness Calulator for 71 and 84 degrees

All you need is the target frequency and velocity factor for this one. However, if using economy coax, your quoted VC may be off, so if that’s the case, you may want to measure a 90 degree test piece (that’s also shown in the calculations).

To check for accuracy, you can cut a 90 degree section of coax and short out the end. Attach to your analyser and you should get zero SWR at the target frequency. Just a tip.

Here Is the Excel Spreadsheet: phasing harness calcs

Quick SWR Calculator for Vertical and Dipole Ham Radio Antennas

Here’s a really simple way of double checking how to much to trim your antenna elements.

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.


* Thank you to Aubrey (AubsUK on YouTube) for the Online version below:

Resonant Now

Frequency that gives a perfect resonance
WaveWavelength of the resonant frequency
¼-WaveQuarter wavelength of the resonant frequency
LengthTotal length of all elements for the resonant frequency

Aiming for

Target frequency for perfect resonance
WaveWavelength of the target frequency
¼-WaveQuarter wavelength of the target frequency
LengthTotal length of all elements for the target frequency

TOKYO HY-POWER HL-700B 600 Watt Amplifier purchase

So I have just taken delivery of a very gently used Tokyo Hy-Power HF linear amplifier.

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. Continue reading

Adding 80m to DX Commander All Band Vertical (9-bands 80m through 6m)

Regulars will know about the DX Commanders very cool results which are now filtering through in real world successful contest scenarios.

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.

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DX Commander Contest Antenna achieves top placed UK IOTA Station

IOTA-graphicI’m absolutely delighted to report that I was placed 4th overall in the world for IOTA-Fixed station, Unassisted, Low Power, 12-hour section. This was from a holiday home and I installed the antenna inside 1-hour.

Results here  – but what makes this more remarkable is that I only used the one antenna from 80m through 10m; DX Commander All-Band-Vertical.

For 80m, I confirgured the DX Commander as an Inverted-L, replacing the 30m element. Of interest, 30m was still achievable (albeit with a 4:1 SWR). Although 17m is not a contest band, I did notice some slight interaction with the new 80m element, however SWR was still acceptable without an ATU.

I logged 300 QSOs however I notice after adjudication, that fell to 289. Pretty good, only dropping 11 QSOs. And I was amazed at how effective the 40m element produced such startling results on 15m, effectively as a 5/8th. Even 10m as a 2.5m long, ground mounted quarter-wave was getting in the action with short skip too.

All in all, I’m extremely delighted that I test-proved this antenna from a holiday location in competition with my peers, who were using genuine fixed-station antennas.

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”.


Banana 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 external metal sleeve over the coax and connecting the sleeve to the braid of the coax so that the antenna appears to be centre-fed with an outboard “sleeve”. Some commercial CB antennas are also made this way. Continue reading

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 while to get to grips with this because although the band-police are complaining – and the RSGB has also warned users, nobody is giving a clear instruction on how to achieve staying completely within the band allocated to us.

In the UK therefore, there’s a couple of simple steps to take to make sure you won’t transmit out of band.

If you don’t have JT65 already, get it here:

Run the installer and interface your rig as you would any other piece of software that connects to your computer. If you are after help with that part of the problem, there are other places to hunt solutions down, not this blog.

Go to file > Settings and click the Frequency tab at the top and edit the frequency for the 5 MHz band so it reads 5.356.

File > Settings > Frequencies

File > Settings > Frequencies

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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 with the ITU World Radiocommunication Conference(s). Many countries are now “on air” and can be heard. Be careful though, their frequencies may be different to ours.

In the UK, this boils down to 100 Watts maximum transmitter power and 200 Watts effective radiated power (* see note). Only Advanced licence holders are allowed on 60M band. You used to obtain a NOV however I believe that’s finished now.

To get around remembering everything, it’s probably best just to set up some memories in your HF set. I don’t know about you, but all these fancy rigs come with memories – and we never use them. Well, I didn’t up until now. 60m is ideal for getting up to speed with these Memories (and you can scan the channels too which is something else few of us know how to work!).

The following table should be able to set you up for your HF set memories (as at February 2017).

Frequencies: Upper Side Band (USB)

  • 60m-band-plan5.298.50
  • 5.301.00
  • 5.304.00
  • 5.320.00
  • 5.335.00
  • 5.354.00
  • 5.379.00
  • 5.395.00
  • 5.398.50
  • 5.403.00

Continue reading

5.137 MHz 60m AM transmission test

So I’ve been fooling around on 60m band lately on SSB as well as CW and digital modes.Today I decided to see if using AM might strike it lucky for me.

AM is a mode I remember from my youth. All the original imported CB sets were AM at that time and I seem to recall that I enjoyed the sound quality. Somehow it’s more relaxing than FM. Maybe its because you don’t need squelch, I really don’t know. FM has great clarify but AM just has a roundness to it.

TS990s on AM

TS990s on AM

Most modern radio sets come with the ability to transmit on AM but there’s an element of setting up, for instance with an old fashioned AM CB radio, you probably don’t set up the carrier and then adjust the microphone gain to achieve the modulation.The good news is that out the box, my TS990s seemed to transmit AM pretty well. I have an additional benefit in that the AM carrier on the TS990s is 50 watts, with voice peaks naturally falling at around 100 watts, perfect for maximum juice on the 60m band which limits our power to 100 watts anyway.

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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 if you multiply the quarter wave resonance by 3.03, you’ll have the next available usable band. In this case, if you tune a 40m vertical to 7.00Mhz, you’ll have the whole of the 15m band to play with with a centre-point of 21.300Mhz. Oh, and you’ll still have the whole of 40m band under 1.3:1.

Now here’s the controversy:

Most people who read antenna publications or the ARRL handbook believe that if you actually make this antenna, you’re creating a cloud-burner on 15m.

Technically correct (sort of) – but for DX, wrong.

On the surface, the 10m long 40m vertical that’s used on 21.225MHz does indeed look like a cloud burner. Here it is. 15m band in green -vs- a pure quarter-wave in red).


(click to expand quarter-wave in red, three-quarter wavelength in green)

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CQWW SSB 2014 Example QSO recordings

DSC_0041Had a ball with CQWW this weekend putting just over 1,000 QSOs in the log. 10m was very busy. The band scope on the TS-990s radio was extremely full with hardly a gap from 28.300 to 29.000 (and some!).

A couple of times, I used Audacity (software) to record out the back of my Kenwood TS-990s and caught some interesting sound-tracks.

Mostly, I forgot to hit the record button, particularly when I hit a very fast pile-up to the US but I found time to catch the tail end of this one after it had slowed down a bit.


Here’s a “perfect” example of a CQWW “rubber stamp” contact.   Continue reading

ACOM 2000 Flightcase

I had a case made for my ACOM 2000 made a few years ago. I’m pleased to report that it’s a great addition to the Ham Radio stock of toys and extremely handy for Field-Day operation.

How to build a tilt-over 60 foot antenna mast from scaffolding poles

This job is not for the feint-hearted. You will need a natural tendency for engineering, be accurate and be comfortable with knots. However, there’s no reason that most small teams of keen amateur radio operators can’t build this as a project for field day use.

Let me explain how I built the one shown in the pictures, then I’ll cover the learnings with you later along with my own do’s and don’ts.   Continue reading

What size pole to insert to a steel scaffold tube?

Most radio amateur operators look at a pole* and immediately wonder how they might use it in their hobby. It becomes a weird past time and can become somewhat of a burden when passing for instance, a section of tubing in a handy-man store. I have to stop and work out if they nest together – or will they go inside some other tube I might have.

However, I have solved one riddle which is what diameter pole can I slip inside a standard steel scaffold tube?

Continue reading

Solarcon Imax 2000 Review 5/8ths Vertical Antenna 10m

Dsc_0002I always fancied a low-angle vertical for 10m band and after doing my research, came across the Solarcon Imax 2000. It was a toss up between this, a Sigma 4 copy or the Sirio 827. The Sigma 4 is now called the Sirio Vector 4000 and I discounted this one because of the size of the radials which seemed excessive for my plot , Same with the Sirio Vector 4000 which is just too tall. Even so, the Sirio Imax 2000 is still 24 feet in length. But read on, it’s actually fairly stealthy for such a tall antenna.

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Success rates calling CQ on BPSK 125 Digital Mode

BPSK125 CQ CallI’m currently using DM780, parrt of the Ham Radio Deluxe suite of programs to conduct my digital hobby. Some of the modes are extremely fun – and I particularly like the very fast speed of BPSK125.

Recently, I have improved my very success rates calling CQ with this script:

PSE K<stop>

I think it mst be quite a compelling trace to follow on the waterfall because once I get to zero and ask PSEK, I more often that not get a hit. It’s certainly better than the old standard :

PSE K<stop>

But it’s only for fun!

Latest Version 5 HRD (Ham Radio Deluxe) Download

I used to host the last free version of HRD version 5.XXX however I had a (VERY) polite note from Dr Michael Carper (WA9PIE) explaining that the version I was hosting here, was actually compiled by the new HRD team, after they purchased /acquired the rights from Simon Brown.

Michael was at pains to explain that he wasn’t being heavy handed, he just wanted me to know that technically, I was giving away *his* product.

Silly me!

That download has now been removed – but I’d like to take this opportunity to congratulate Michael on his tone, friendliness and professionalism. In this modern fast-paced world, it’s becoming a rare trait.


But WAIT! The latest version of HRD is actually better and has amazing support too. Version 6 is awesome and has a number of enhancements including a wider selection of rigs, FSK keying etc etc.

Suggest you check the HRD guys out here – and there’s a 30 day free trial!


ACOM 600s automatic HF linear amplifier

James (M0YOM) and I are pretty excited about a new automatic, solid state linear amplifier from the ACOM stable. 160m through 6m with continuous duty rated at 600 watts. Well, when I say portable, I mean it’s more portable than say the ACOM 2000 – but still heavier than say an AL811. But hey, it’s super sexy, automatic and has that amazing legendary ACOM metering and inbuilt protection.

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TS990s External Keypad

I recently had the privilege of dealing with Chris Taylor of Taylor Made RF who supplied me his rather excellent custom keypad for the Kenwood TS990s.

Chris gives the device the part number TMRF TS990KP and it follows the convention as outlined in the user guide 16-7 of the TS990s user manual which allows for the user to program each of the 8 function keys a specific task, for instance; change antenna, play a recorded voice macro or change filters. An extremely handy accessory.


Of course, you could build one of these but for an “appliance” operator and for sheer mini-bling, the TMRF TS990KP is a delight to use. It comes very nicely packaged with basic instructions, a simple 3.5mm jack to jack stereo lead and of course, the engineered keypad.

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Email over HF – WinLink with TS-990s problem solved

This note for TS-990s geeks who are running WinMail and RMS Express.

It is natural to use the Data menu item in position one for Voice (via microphone). On-screen, this will show as “USB”, top left of the monitor. Upon holding the button “Data” for a second or two, you can confirm that the microphone is selected for this position.

  • See the problem below

Demo of RMS Express at bottom of this article

In the event that you use RMS Express with a TS-990s, Continue reading

Kenwood TS-990s User Review

dsc_0228I finally took delivery of my TS990s in early January 2014 and it came with the latest firmware from the factory. First impressions, distilled into single words: massive, engineered, beautiful, functional, imposing, radio bling. But not a microphone in sight which I thought was pretty odd but they must have got their sums right, I would never had used a cheap mic on this wonderful radio anyway since I use a stick mic on a table boom (Heil Goldline) but it would have been good to check without making up a cable.

dsc_0231Everything about this rig is solid. My expectations had been managed by all the articles that I’ve read on the internet about the radio and I double checked the radio when I compared both the FTdx5000MP and the TS-990s at the RSGB convention in late 2013. For me, the TS-990s was the winner, although more expensive. The main reason for switching my allegiance from Yaesu was the size (I like very large radios), the in-built monitor and scope function, and particularly the fact that a single USB cable connects the rig to my WIndows 7 PC, effectively de-cluttering my MK2R+ SO2R system. I was fed up with all the wires everywhere. Continue reading

Splatter or Receiver Overload?

Some operators mistake what is actually their inadequate receiver circuits as “splatter”. Genuine splatter that causes annoying interference on the band is very rare. What is more regular is operators assuming that the products they are hearing is splatter. It’s probably not.


TS-2000 suffers with close-in strong stations

For years, I ran an FT1000MP at home and I would curse under my breath, those stations that slid up to me in a contest, just a kHz away and started calling CQ, particularly the 80m activity nights. I would hear that typical crackle and scratching sound which was louder than the station I was in QSO with. I would bail-out and find another frequency. I couldn’t believe these stations had the staying power to stick next to me since clearly they would be receiving the same crackle from me – as I did from them. Or did they? Something was odd.

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Special Event Operating Procedures


Callum, M0MCX

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 appeal to me in this hobby, fancy radios, interesting antennas and GREAT operating. I enjoy making my hobby more fulfilling by operating well, and I don’t just mean following my license conditions. I like to mimic great operators, those guys that sound clear, even under QRM and QSB, they mean well, they act professionally, like they’re in Mission Control during an Apollo Mission. They inspire their contacts to act professionally – even the Italians don’t scare them! Someday, I hope I might be half as good as them 🙂

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Designing a Radio Ham Shack

I can’t remember how many times I’ve moved my shack around. And when I do, it’s always wrong, it doesn’t look quite right and nothing fits where it should.

m0mcx shack redesign

Further, just when / if I do manage to get it right, I need to get to a particular piece of equipment that’s stuffed away perfectly on a shelf. I seem to spent more time dismantling the darned thing to get the piece out to either take to a field day or have it fixed.

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511 QSOs – Cornwall DX-Fest Conclusion 2013

2 Weeks in Cornwall seemed to go in a flash but in between QSOs, I did manage to find time to repair my website and get it back and running again. I love documenting the fun and games I have whilst I enjoy the science of RF. I trust you enjoy it too.

cornwall qth

Firstly, thanks to everyone who gave me a QSO. I exclusively used a pair of verticals. Antenna #1 was the 40m vertical (actually 9.6m in length with 16 radials) which also gave me a 5/8th style antenna on 15m. Antenna #2 was the dual fed 20m and 10m verticals, similar to a fan dipole. More accurately I would call this a “nested” vertical.

I ventured onto 80m band for an hour but conditions were abysmal compared to 40m so you’ll see many of my QSOs were on my favorite band.

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Amateur Radio with low electrical noise

40m and 20m verticals

40m vertical (left) and 20m/10m Nested Vertical (right)

I’ve been running many pile-ups on 40m this week and I think half the reason is that I can hear so well because the electrical noise is almost non-existent. Of course, my TX is also pretty good because of the salt water too.

Working conditions; My “holiday” rig, Kenwood TS-2000, Heil Goldline, NC10 netbook running N1MM “DX” mode with a RigBlaster for voice keying and my Acom 2000 to loaf around on.

Continue reading

Microham MK2R+ Installation

I’m pleased to report that James (M0YOM) has successfully installed our Microham MK2R+ recently. This means that we can now use the FT1000MP *and* the TS2000 at the same time, ideal for SO2R.

This means that whilst I’m CQ on 40m band, I might be listening up on 20m, waiting for the band to open. Just hitting the appropriate footswitch would, in an instant, switch transmit over to the 20m band and allow me to QSO up there (and of course, carry on listing on 40m band at the same time).

In fairness, we’ll rarely use the station like this. Frankly, it’s more of a convenience of having just one microphone, one computer logger with an integrated two-radio setup and full digital modes from 160m to 70cms.

Cheers James!

CQ WPX 2010 Amateur Radio Film

I finally got around to doing the final edit for the CQ WPX Radiosport Contest. Please don’t take the film too seriously, I was really poking fun at us! However it turned out quite pleasant in the end although the title sequence at the end is a bit of an overkill 🙂

Give it a peek and comment accordingly.

*Note: The WPX contest is based on an award offered by CQ Magazine for working all prefixes. Held on the last weekend of March (SSB) and May (CW), the contest draws thousands of entries from around the world. Many stations erect large radio aerials just for the competition. Yaesu and Icom radios compete to be the radios of choice amongst the top amateur radio stations.

73, C.

160m RSGB Club Calls Contest 2009

One mistake (apart from entering) was going S02R for a few moments and sliding up on the 2nd VFO to the fellow on 1950. I carried on CQing until my off times coincided with his off times before giving him a blast.

Woops! I bluffed my through the contact since he took rather a long time in repeating everything and I nearly lost my run freq, so half way through his over I started CQing again – and still managed to work out the report! I was logging both him on 1950 and my own contact on 1947.20! I must have sounded deaf to the poor fellow who I kept asking strange question to on my own frequency, to piece together the report at the same time as working the chap on 1950, “Did you say Member or Club”? and hoping for short, to the point answer.

Very funny, but I stopped that pretty quickly.

Region 1 Field Day 2009

M0XXT SSB Field Day 2009Field days seem to whoosh by in a seamless tirade of bodily abuse that starts in the balls of the feet, grows through your hands and wind blown cheeks before reminding you that you are starving hungry and you’ve only just taken over the driving seat.

A very dissapointed 1012s QSO this  year and we still can’t work out why we lost ground so fast with the other leading stations, even on 80m where we should have held our own. Certainly having a tribander at only 35 feet is a hell of a penalty to have to suffer every year, but why our 40m and 80m runs were not producing the numbers that the other high-flying entrants were managing? I just don’t know. High probably does mean might. Last year’s 1,000 foot entry was very different on the higher bands to this year. Mostly, we were firing right through a heavy forest. I wonder how much attenuation there is in 500 yards of dense oak trees that are about 80 feet tall? Well, you get my drift.

Filtering this year was amazing. We used a second rig as a dedicated 2nd receiver using James’s new Band Pass Filters, made to Bob Henderson’s designs and we had negligible breakthrough. I can’t wait to use the new permanent multi-two station when we have the stub filters in place too.

Anyway, although I’m gutted that we probably didn’t even make the top three, we still had a good time and achieved some learnings too. Contesting for me is about three things, learning, competing or having fun. Ideally, all those things. This year I had all of them but not at the same time. Knowing that we were beaten within 2 hours of the kick off made me push extremely hard, but we just couldn’t catch the leaders. Grrr.

Oh well, next year we’ll be back, stronger, cleverer and with a better strategy.


Quadrifilar wound toroids (and Coax Cable stub filters)

quadrifilar wound toroidJames (M3YOM) has just emailed me after discovering something worse than fitting 90 or so PL259s last week; it’s winding quadrifilar wound toroids. Pictured is a completed L1 winding for the 40m filter. He says that it’s a T130-0 core with 7 quadrifilar windings which should give around 3.96uH and there are two in the filter box he’s making from a kit supplied by Bob Henderson.

Since James took on the job of producing a fully filtered Multi-Two station, he’s soldered nearly 100 PL259s and not one of them was faulty on the day. Good job OM!

James, the wire looks like that stuff we made the MegLoop with, is it?

James says:

“It’s not the megaloop wire, the Lo-Z winding (yellow wire) is 1.25mm solderable enamelled wire and the Hi-Z winding (Red wire) is 1mm solderable enamelled wire. The enamel is designed to burn away at low temperature so you can solder it directly without the need for striping it back first.

Incidentally, Bob’s callsign is 5B4AGN (he used to be a G3 before he moved) “

Bob, I’m sorry you used to be a G3. You should know that I’m forever poking serious fun at G3s, as they poke fun at M3s. Maybe you and I can form a truce and make the world a happier place?

73 all, particularly my new G3 friends.


M0XXT CQ WPX 2009 (Amateur Radio Contest)

M0XXT UK Scout Contest TeamMy thanks to Lee (G0MTN) James (M3YOM) Terry (G4MKP) and Aidan (M6TTT, Scout) for getting our new station on the air for a first-time-out on WPX.

We also roped in Chris and Dan, two new foundation student contest Scouts for the spotting on the Mult Station. Barry M0DGQ also gets a big thank you for supplying hundreds of meters of 75 ohm coax for James’s stub-filter project and Charles at Moonraker for sponsoring the large number of required PL259 and T pieces.

We ran a pair of very old Yaesu FT1000MPs (non-Inrad versions) which were completely swamped by QRM to a number of interesting antennas including our new super all-band Mega-Loop (horizontal delta loop at 85 feet) delivering about 12dbi on 20m to US at 10 degrees elevation (more on higher bands). However, it also delivers 10dbi to EU and most of Russia at a very low angle, hence QRM flooding. James’s stub filter project worked but still needs some tweaking. Thanks to K1TTT for helping James get his head around this. Next time, James will have finished Bob Henderson’s filters as well which should sort out any final interference between bands. Poor James soldered nearly 100 PL259s last week. Don’t worry James, fingers should re-grow by CQWW!

The mult station ran Terry’s A3S at 30 feet on my hydraulic tower and also switched in a 200 foot doublet at 80 feet across the tree canopy behind the Scout Hut for the low bands (which worked great on 40m DX but rubbish for 40m NVIS). Need some switchable low dipoles for EU.

We had an initial target of 2,500 QSOs and 1,000 mults and just missed both by a whisker.

  Band    QSOs     Pts  WPX 
   1.8     152     301   50 
   3.5     574    1513  313 
     7     866    2203  264 
    14     722    1378  269 
    21     102     254   63 
 Total    2416    5649  959 
Score: 5,417,391 

We had two breaks of 30 minutes each to sit and have dinner / lunch as a team, an important lesson to keep morale and spirits high. Some day we might not be able to afford time off, however whilst we’re still novices and part-time, we can afford to have a lazy lounge around. We sent our score to GETSCORES every 5 minutes automatically fed by N1MM on a local wireless LAN picked up from my house about a 900 meters away. S51A and ourselves played ping-pong on the scoreboard for the whole 48 hours and we’ve since become competitive friends.

We particularly liked GETSCORES since it’s a way of interfacing with the rest of the world and having even more fun. I don’t understand why more stations don’t use this system. The USA seem to embrace this stuff quicker than others.

There were many highlights. Working VK on short path AND long path on both days on 40m was a privilage. Many more experienced contesters might have done this before but at last a first for me. Having the young non-licensed Scouts successfully finding some RED mults on N1MM was cool. Being called in just to work them was even cooler! Handing the headset over and telling them, “Great. Find some more!” was even better than cool! James’s run into South America was nice on 15m on Sunday, as was the long run on 20m band. Being spotted three times in 5 minutes from the West then the East then the West again was like using a very high gain vertical (which was the bloody trouble actually since we couldn’t dial out the QR Mary).

Like all (good?) contest teams, we’re now working on massive improvements since the station only came together on the Thursday and we started transmitting essentially 90 minutes before the off. Everything worked, nothing broke. Amazing.



GB1DSG Special Event Mega Loop Project

Aidan M6TTT

Picture shows Aidan, M6TTT running his first pile-up from the Hut. First class Aidan, you really got the swing of this on Sunday. Fabulous effort.

We put nearly 800 QSOs (contacts) in the log and there are so many highlights, I can’t begin to mention them all. My personal highlight was working VK3FT at lunchtime today with a land-line quality copy on the 20 meter band. Keith spotted us which probably accounted for flurry of VK stations immediately afterwards from Australia. Thanks Keith.

We got spotted 25 times over the weekend which is certainly our personal record. Thanks to those stations that helped us maintain the pile up!

As usual, we used the MegaLoop (delta-loop) antenna, see this page for details:

Cheers all!


GB7HQ Amateur Radio HQ Contest!

In 2006, GB7HQ was actually GB5HQ. It was changed due to concerns by the CW crews that too many errors were creeping in due to misheard calls.

I originally wrote this article in 2006. It was published in the CDXC magazine in the same year. I’ve just remembered that I never published it here.

Fraser working GB5HQ

Frazer G4BJM

I am still pinching myself having operated the “beacon” station, 80m SSB as GB5HQ for my country along with Lee (G0MTN) and Fraser (G4BJM). Operating GB5HQ was the highest highlight of my hobby career yet. It inspired me to dig deeper and to discover more about myself and it certainly gave me the chance to stay awake for 24 hours!

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160m SSB Club Calls Contest – November 2008

Dorridge Scout Group M0XXT HQ107 in the log. I’ve no idea what my score was since I used N1MM’s DX Serial Contest template to do the logging and the miscellaneous field for logging random text did a hopeless job of being able to edit long club names efficiently.

The last time I entered this contest, my log was called into question when the adjudicator asked me to clarify what I meant by the club station “Reading”. It transpired that there was only one radio club in Reading anyway. I vowed not to do this again but I’m back.

This year, I had the added luck of G3WZT CQing 1.7kHz up from my run frequency of 1.903 MHz on the off at 8:00pm. Yes, I had been talking to James for about an hour prior to the off and yes, of course he would have noticed me there – but his deep concern for our predicament was (to use his words) “tough luck”. John, thanks a lot, 1967 RAE passes were obviously excellent vintages. I’ll endeavour to remember you next time and offer you my run frequency quicker than you can say, “I’m a G3 and I certainly act like one”. I wonder if you behaved like that in 1967 when you had a fresh RAE pass in your pocket and a 12wpm ticket?

Luckily for me, the scout hut was warmish during the event so I wasn’t doing my normal teeth chattering. I took a 20 minute phone at 10:00pm from Wendy which gave me a break but I missed a few because of it and then S&P’d for a while. I notice that there were actually very few clubs playing which was strange. I would have thought this would be more popular. EI and DL stations were playing too, giving Non Member reports bar one DL who gave his full radio club, bless. I wrote Non Member in my log but didn’t tell him so not to cause any upset!

Absolutely nothing wrong with the antenna; 174 metre equilateral triangle at 85 feet fed with 4:1 balun and coax in one corner. It had good ears. Only three stations I gave up with and two of them were in mainland EU; a PA and a DL. M3s (and M6s) were heard well on their 10w. I notice last year’s top score made 130 Qs which was a reasonable benchmark so I’m fairly pleased with 107 bearing in mind the proximity to “John the G3” and that I had to take Wendy’s important call at 10:00pm. I could only make more if I was either slightly more lucky with the G3s – or played more seriously with SO2V.

Will I do this contest again? Well, I’m not used to a) the quality of operating (come on, it was a bit geriatric) and b) I’m not that keen on the rules. Even just logging the Town would do justice to copying something interesting and different, but logging “Wensleydale Cheesmakers Transmitting and Electronics Amateur Radio Society” is a bit of a mouthfull. In light of the fact that this contest is apparently a route to getting newbies interested in contesting, forget it. Committee, do yourself a favour and get into my head. I have M3s that want to operate. Give them something they can do and build their copying (and confidence) skills, not drown them with difficult reports under heavy QRM.

Anyway, Sunday’s Remembrance Parade was fabulous. I was back to Front Rank Drummer again after all these years. Great!



Waterproof PL259 connectors for Ecoflex

Waterproof PL259 ConnectorsI’ve been lucky enough to purchase 100 meters of Ecoflex 15 recently and the solderless connectors are awesome.

Available for Aircell 7 (RG213 replacement) and Ecoflex 10 (Westflex replacement) and this giant 15mm diameter stuff, once fitted they are completely waterproof.

My experience with all these products started with me laying down a few runs for my narrowboat earlier this year because I wanted a low RF leakage product. More recently, I’ve rebuilt most of my spare patch leads with the remainder of the Aircel and Ecoflex left over from the boat build. All my RG213 and Westflex has been relegated to tutoring and testing.


SSB Field Day 2008 – M0XXT

2008 will go down as a wet year. Both VHF NFD and SSB FD was a soaking experience. Luckily, as with most close knit teams, we laughed it off and worked through it, however a tough act all the same.

Lee G0MTNArriving at the site on Lunchtime Friday, I got the tent up in a complete hurricane. Stripped to my shorts and a T-shirt in the driving wind and rain and all on my own, at one point I just burst out laughing at my predicament. The only thing that kept me sane was the knowledge that some other crazy people in other parts of Europe were also following my example and getting their stations worked up.

Finally at about 15:30hrs, I had a tent up – and all the tent pegs used up, a sure sign that I had screwed the thing hard into the ground. Sporadic rain continued as Terry and James arrived to part assemble the A3S.

Eventually, James and I were left to our own devices to continue building the working station in the tent, networking the machines and arranging the PCs etc. Still, no antennas had been erected.

After our meal in the evening, a quieter weather front descended on us and with still an hour of light left, we put up the 60 foot mast that would house the 40m and 80m fan dipoles. We kept pushing and pushing, even firing up the lighting rig to give us 10kW of light to finish the job (at 1:00am in the morning!). Both dipoles tuned fine, fed off a single 1:1 balun at the top with Westflex straight to the tent. Only the A3S to mount in the morning.

Indeed, with Terry and Lee’s help, we had the A3S up at about 10 meters by mid-morning and we ran a few numbers whilst checking N1MM’s implimentation of Reg1 Field Day. Unfortunately, I missed a trick and for the whole contest, we ran without automatic multiplier recognition. Scoring was right, mults weren’t. What do we all tell everyone to check? The software. What didn’t I do? Grrr! Plonker!

With a couple of spare hours left, I erected the RX loop on a spare mast on a Barenco wheel clamp, running some RG58 back to the tent. Big mistake since the coax “leaked” too much which meant that some bands were difficult to spot due to proximity to the TX antennas – even running Barry’s new Stub Filter switch that he had made for us – but we’d just ran out of decent stuff.

The next 24 hours was a blurr of operating, cups of tea and running repairs. The only real thing that let us down was the 1:1 balun driving the fan dipoles on 40 and 80 which seemed to go open circuit. At 7:30pm on Saturday evening, we dropped the mast, stripped out the balun and directly connected the coax via a spare dipole centre. This meant that Terry carried on running on 20m for longer than he wanted but the propagation came back and he ran a string of West Coast stations prior to dropping down to 80m. Maybe a blessing in disguise?

Lee’s Saturday afternoon stint was taken over by Terry and both left the site by dinner time to leave James and I to run the night shift. Doing half-hour on and half-hour off, we managed very well. It was one of the most interesting night shifts I’ve done. I think staying fresh with only 30 minute stints may have helped. On the other hand, sometimes I wanted more time on the mic, but as a compromise 30 minutes seems about right.

Big contests aren’t right without the obligotary ZLs and VKs early on 40 meters and we were pleased with a small crop of these. Fresh as a daisy, Tim and Terry arrived back on site within half an hour of each other at around 6:30am to allow James and I to hit the sack for three hours sleep, rising just before coffee time in the morning.

I hate the last couple of hours of the /P contests. I know it all has to come down and everything needs packed away again so to get ahead, I dropped the RX loop and packed away the second receiver station, neatly arranging everything in the tent door before lunch.

Blur descended on us. Looking back, everything is in speed-up mode. All I can remember is getting in the bath at about 5:00pm on Sunday night knowing that the car was still jammed with gear.

Enjoy the photos – and write back if you like my drivel!

Cheers and beers,

Callum, M0XXT Team Owner!


JOTAMassive success this year with the new antenna, generating huge pile-ups world-wide. We shall never go near 80m again for JOTA. 20m is the band that synchronises extremely well with passing Scouting messages around the world, particularly if you have a technically proficient station and crew.

I notice Tim (M0URX) has done a little write up of this event here:

Needless to say, if having ones Cub pack sending their greetings message to the Father in Law to the Crown Prince of Brunei isn’t one-upmanship, I don’t know what is 🙂

It is just for me to say thanks to Tim, James and Terry for helping me put on such a sterling event. The QSL cards have started arriving already! Fabulous.



CQWW – M0XXT Report

This year, James and I ran M0XXT at the Scout Hut using a pair of XXT Mega Loops; a full size 160m version and a half-sized one which suited the top end of 80m and 10m. Full-sized Mega Loops don’t work on 10m. I ran out of time to put up a TX vertical for top band, even though I did finally finish making it ready for tuning by Saturday morning during my “off” times at night. Another job for next year.

M0MCX running M0XXT CQWW 2008RF was via one of our FT1000MP radios and amplified by an ACOM. A pair of Dell PCs running N1MM did the logging. We networked the PCs for disaster recovery purposes and used the second copy of N1MM on the spare PC a couple of times when RF shut down the run machine. We were Multi-Single.

The antennas really worked miracles, showing almost unbelievable gain which in the main distil to 6 equally spaced compass fingers or lobes – with the main RF being squirted at around 290 degrees (since it’s slightly twisted off it’s X axis due to the perfect location of the local oak trees for USA propagation). I won’t bore you with the compass bearings, it is suffice to say that these RF fingers cover most high density population areas of the globe. The whole topic of these XXT Mega Loops needs a chapter to themselves and as I write this on Monday evening, I can report that this afternoon I ran a huge pile-up to the west coast US at about 16:00z, at one point switching the amplifier off and continuing to run the pile up with 10 watts (!) which reduced our average incoming signal report to 5 and 7 from 20dB over S9. Even on 40m, the gain figures are healthy with 5dB at 10 degree take off angles to the US. 80m is just a big bubble of RF but with the antenna at 90 feet elevation, at least the bubble has some flatness to it. Same with 160m – hence the idea of a massive vertical.

No real technical surprises this year. Everything worked out first time, only after updating SCP did I realise that M0XXT wasn’t shown in the database! What a numbskull. I meant to drop Randy a line to ask for this new call to be added. Having our call queried heavily was quite normal and tedious.

Strategically, we didn’t really have a plan. We believed we would conquer the world and be louder than anyone else(!). We’d just shout louder 🙂 Of course it doesn’t work like this and after my 6th CQWW, I can genuinely say that I was yet again blown away by the strong signals on 40m. I even reminded James that this would happen, but it was worse. Isn’t it always like that? This damned loop might be great on TX but you can’t dial out the QRM! I feel some receiving antennas coming on..

I can’t remember when I slept. I do know that between Friday morning and Monday morning, I had 5 and a half hours of the stuff and my diet consisted of everything that the Weight-Watchers lady took me off! I haven’t eaten like that since I was 18 🙂

As a team, we had some fabulous times scoring 97 countries on 20m and 92 on 40m. We wanted DXCC on both bands but it wasn’t to be. Had we known that 10m was going to close on Sunday, we’d have spent more time increasing our multiplier-score on that band during Saturday. Experience counts and we lack quite a bit sometimes.

W3LPL spotted M0XXTI personally had a couple of exceptional highlights that I’ll remember for a while. The first was on Saturday evening, running a split to the US on 40m and getting a pile up for my money. The rate meter peaked at 230 which I thought was pretty darned good. At one point, I burst out laughing with a mixture of adrenaline rush and terror! I have never had a high-gain antenna to the US and just didn’t think that it was possible to have so many people calling you! Getting spotted by W3LPL made it worse (or better..!!).

The second was during the last half-hour of the contest. We happened to find a tiny gap at the bottom of 80m. I was happy just to score a dozen stations and wrap the deal up. Instead I had another pile-up after being spotted by an EI station. When I remembered to look, the rate meter was at 199 whilst I worked 60 of the bigger ticket Dubyas side-by-side DK and PAs inside 30 minutes. Showing off? You bet! Just fantastic.

Most of the time, we doubled up on the headphones with the spare man checking email and stuff, on standby for some nasty QRM busting ears. N1MM has the CTRL E feature for shooting messages to each other. We used this to fire callsigns at the runner to help them out. Well, I happened to hear an Italian station call us and he used our callsign so we didn’t confuse his call to us for someone else. His pronunciation of “Xray Xray” can only be described as “eggs-ray eggs-ray”. I thought this was quite funny and shot it over to James using the CTRL-E feature. What happened next is one of those moments where everyone gets the giggles. I had to run out the room and laugh out loud in the park (in the middle of the night. No wonder the locals stay away from me!!).

The precise scoring is on a memory stick so I’ll have to report that another time, however we made just under 1.5 million points – and although the station was running for 48 hours, we had plenty of downtime and research moments. James and I can be accidental science professors and it’s unfortunate when a great idea for a piece of software or a new antenna pops up. Everything has to stop while we consider it. Of course in the middle of a decent run this is impossible but band changes can slow the rates down to a dribble. The mind wanders and before you know it, we’re demonstrating a new system of antenna erection or a complete re-write of N1MM. What a hobby!

As I was drifting off to sleep last night (like a breeze block!), I remembered a load of lessons learned topics to write down. Now I can’t remember them. My top tips therefore rely on my favorite topic; having fun. It’s just a game.



XXT Mega Loop Update

XXT Meage LoopSaturday / Sunday saw us tear down the minutely designed and executed 28.5m leg triangle and on the spur of the moment, we put one up twice the size. It only JUST fits at 57 meters each leg, and again this is a perfect triangle. At 20m in height, we should have experienced nearly 15dBi towards North America and sure enough we ran a string of US stations all Saturday and Sunday scoring on both days into California with signal reports in the 57s and 58s. Exceptional. But these lobes don’t just work into US, we worked Ethiopia, Brunei, Bermuda, VK9, the list goes on and on. This is a serious loop and great fun for running on – it’s also nearly invisible!

For the geeks, this is essentially a perfect triangle – and it HAS to be a perfect triangle otherwise you won’t get these high-gain lobes. Squares and circles are for the low band cloud warmer brigade, this is for the higher band DX hunters and goodness did it work well. It’s an instant pile-up generator.

Shall we use for CQWW? You bet – and we’re looking forward to a couple of thousand contacts and I’m so impressed with it, that I might put it up again next year for SSB Field Day since as an all-band antenna, it works from 80m upwards. Indeed, it will also work most comfortably on 160m (since it’s really a single wavelength for 160m) but we rarely go down there.

Look out for my Jamboree On The Air report where I’ll discuss this antenna – as well as our success with the Beavers and Cubs last weekend. Needless to say, if having one’s Beavers passing greetings messages to the Father in Law of the Crown Prince of Brunei on 20m band isn’t one-upmanship, I don’t know what is!



Firing guy wires over 100 foot trees

My other recent article discusses our XXT Loop that relies on three very high trees equally placed as an equilateral triangle would be. Initially, my design focussed on a 2 wavelength loop for 80m. This required not only a serious amount of high quality copper wire but some extremely capable trees!

Cutting the design by half had some advantages, namely I needed only 80 meters of hard-drawn copper wire instead of 160 meters and I could trade off the whole of the scout field into something a little more manageable – three trees nearer the shack! Luckily, I recently found 600 meters of high quality enamelled antenna wire going for a song (eight quid actually!) which has assisted this experiment 🙂

XXT Loop

Anyway, I drew this to scale using Google Earth and Paint Shop Pro and had my Cubs measure the trees one night as part of a badge (very satisfying!). It turns out that these trees are in the 85 to 100 feet feet category, the real Daddies of the local Oak Trees! Of interest, if north is “up” and the feedpoint is over on the far right, the major gain is over to the north west area (WNW to be precise).

Getting rope over the top of these trees was a real test and over the last few days I’ve been doing some major development work into designing something that will reliably shoot a fishing wire over the top of these. May I say now that once I had perfected the “gun”, it is certainly one of the most satisfying and exhilarating events to shoot a weight over the top of a 100 foot tree watching tens of meters of fishing line fly off every second as it lofts over its target. An amazing experience to have it all finally working in perfect unison.

I can hardly bring myself to tell you the precise details of how you can achive this since it cost me not only a few pennies in wasted fishing reels but many frustrating hours (days!) with various contraptions before I hit the nail on the head reliably every time. I know you can buy such “guns” in the USA, however if you really want to accomplish this on a home-brew front, you can either email me with a very grovely email or buy me copious amounts of beer in the local pub to extract the truth!

Catapult Fishing Rod Gun

Since a picture paints many words, I’ve attached pictures of both failures and successes. In the catapult / fishing reel ONLY picture (the first one), the line is essentially too close to the catapult and upon launch, it snaps all too quickly or jerks the weight down to the earth immediately.

Using the extended fishing rod though means that the line is longer which takes up the initial jerk much better as it all takes off. The breaking strain is critical. Too low and it snaps, too high and it’s too heavy and doesn’t reach its target.

Finally the weight. I found that in most cases, a single 10mm heavy stainless nut was suffice. However late this afternoon, a particularly high tree was proving extremely difficult. I needed the projectile to travel further and ended up moving to three 10mm nuts. Exerting as much force as I could muster (more than ever before) I launched the three nuts at the top of the tree and whooosh, it all went over. Extremley satisfying since had I got that wrong, I could have easily crushed a finger or have the nuts fly off into the countryside somewhere. Quite worrying actually, all that force going wrong (indeed having my nuts flying off into the countryside would also have been worying!).

Catapult Fishing Rod Gun

Of course, once the nylon line is over the tree, one has to track it down which easier said than done. Walking around a field looking like a dancing fairy with arms out-stretched to find the line has the locals glaring hard – but the most effective. I tried lacing ribbons and coloured string to track the projectile but this just caused jams and further problems.

Once found, attaching a strong cord is the next battle. Luckily, I have studied knots keenly over the last 18 months to become the district knot champ, however I soon learned that having a knot that would actually undo under pressure was best, not only for the weight on the line but also for the cord. The last thing you want is a stuck weight or cord up a tree. Before I worked this out, I lost about 50 meters of line in a tree in smaller increments. It  glistens most interestingly in the sun. I only hope it breaks down and disintegrates next summer because the thought of it up there is most embarrasing. In the end, I discovered that applying small amounts of duck-tape so that in the event of a stuck line 100 feet in the sky, a hard pull would allow the weight to drop to the ground and the line to spring free. It’s a better solution.

I recently found some genuine American paracord from a supplier on eBay. It’s not cheap but it’s very strong and doesn’t seem to stretch much. I bought a 200 meter run. It has a 500 pound breaking strength so I’m guessing half that is a safe working load. Basically, if I can pull it with all my might, I’m happy. Attaching the line to the cord and pulling it over slowly normally did the trick – well, most times. Sometimes it doesn’t want to play so I discovered the best method of attaching my lines to my paracord to reduce that issue. I’m not telling you which method I discovered since that’s worth another pint of local ale!

Finally this afternoon, I am left with three trees with paracord running all the way up, all the way over and all the way down again. I’ve tied them off using step ladders so the local youths don’t muck with them.

Tomorrow is antenna build day. Wish me luck. I’ll let you know how I get on.

Post Script: Good news, the antenna worked a treat, see:



New Winter 2008 CQWW Vertical

12m Spiderbeam Vertical

When the kids start to play less outside in the winter, I like to experiment with a new vertical each year. This year it’s a 12m spiderbeam vertical fibreglass pole loosely wound with some hard drawn copper wire. A waste pipe supplies the engineering for the radials with the SG230 doing the matching. This allows me 200w of SSB, in other words, a direct companion for a non-amplified 200w FT1000MP Mk5.

Thankfully, James (M3YOM [yomSOFT author]) popped around last Sunday to help me slide it into an old Barenco 2 inch coupler. This mounts on a steel 51mm outside diamter tube which in turn slides into a plastic mini-drain-pipe that has an internal diameter of 51mm from B&Q DIY store – all a perfect fit. I concreted the plastic pipe into the ground in June before the summer hols. It goes about a meter down.

In terms of its performance, it only really works well on 20m and 40m. The rest of the bands are a wash out but as a 5/8th vertical on 20m, I really am getting a couple of db gain over my other antennas. 15m band is comparable to my little super loop and modelling confirms this. 10m of course is hopeless because it’s longer than a wavelength. Until my 2 element SteppIR turns up, this will have to do.

In testing, I was lucky enough to discover a contest closing but with US stations keen to make a last for contacts on the 40m band. Clearly, it’s a winner there and the aerial allowed easy QSOs with a nuber of contest stations in the US. On 20m too, I scored with a number of US stations at around 21:30 local time on Monday eve when the band was still open. Since then, I’ve had lots of fun with it.

Lessons learned? None really. It’s a heck of a size for just two bands though and it sticks out like a sore thumb from all the streets around here since the top is sitting at just under 60 feet. Clearly last year’s version was also a 40m and 20m model but I didn’t realise that then. I did though speak to 23 countries on 160m. I’ll be interested if it still has any top band performance this year – or was that a fluke..?