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MOST READ POSTS . . .

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 ...

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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 ...

Read More

Obligatory evening shot of a three element 40m array

10m Telescopic Flag Pole Antenna Support DX Commander

DX Commander Antennas: These are the best selling heavy duty telescopic antenna support on the market. With over 500 sold and 100% track record, I know what I’m doing – and I use these myself in real-world RF applications. Club members, personal friends and other regular amateurs love the quality and ...

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TS990s on AM

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 ...

Read More

DX Commander pre-production testing all-band vertical

DX Commander pre-production testing all-band vertical

I finally found some time this year to pull all the components together to test out in a real-world setting, the idea of using multiple elements on a single vertical fibreglass pole to achieve very good SWR and radiation patterns. The problem with verticals is than in the main, people need either ...

Read More

Bidirectional switchable 40m wire yagi

I switched on the other evening and heard a very quiet DX caller on 7.142. It was YC0LOU from Indonesia and I could only pick up parts of his call. He called and called and had no takers. In fairness, he was extremely quiet but as the sun was gradually ...

Read More

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 ...

Read More

Obligatory evening shot of a three element 40m array

3 Element 40m Vertical Parasitic Array (VPA) Vertical Yagi

Essentially, this is a single 1/4 wave vertical antenna with ground radials, complimented by a pair of parasitic verticals; a reflector and a director. It will deliver around 6db of additional gain over a standard vertical with a beamwidth of around 70 degrees. I have built mine pointing 300 degrees ...

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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 ...

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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 ...

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

I 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 ...

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How to make a stealth amateur radio wire antenna

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 ...

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Kenwood TS-990s User Review

Kenwood TS-990s User Review

I 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 ...

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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 ...

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Coax Loss Comparison

I can never find the comparison charts between RG213 and Henry Westlake's Westflex W-103. At last, I'll have this logged forever now. Per 100 meters: RG213/URM67(Mil spec) Westflex 103  100 MHz                      7 dB 3.2 dB  144 MHz                    8.5 dB 4.5 dB  200 MHz                     10 dB 5.4 dB  300 MHz                     13 dB 6.2 dB  432 MHz                     15 dB 7.5 dB  1000 MHz                   27 dB 13.0 ...

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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: http://jt65-hf.com/downloads/.

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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One of my aerials has just come down in the wind, a 40m compact dipole arranged as an inverted V with the ends coming down as far as the 6 feet fence height.

My garden is about 15m wide (actually it’s 51 feet wide, so a whisker over) however it’s too small to fit in full-sized flat-top dipole but an inverted V works well. Whilst you are at it, why not add in elements for 30m and 20m and have three bands on one feeder?

40-30-20m-fan-dipole

Width of this antenna is 15m. You can make it smaller to suit.

I have designed this antenna to be a flat top with droopy legs. The centre will be held up with a very sturdy aluminium scaffold pole with a 4.6m sailboard mast sleeved over the top. The aluminium mast will cross-bolt to an already installed steel scaffold bar already concreted in the ground. Bottom line is that I should achieve around 10m in height (30 feet or so).

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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

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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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BuyNowI finally found some time this year to pull all the components together to test out in a real-world setting, the idea of using multiple elements on a single vertical fibreglass pole to achieve very good SWR and radiation patterns.

The problem with verticals is than in the main, people need either ATUs or they use that awful UNUN business with a single radial. The 9:1 UNUN business is just inefficient and the only way to to use an ATU effectively is at the feedpoint, not at the rig-end due to the severe losses.

A feedpoint ATU is expensive and generally requires a 12V power source. And long verticals have awful radiation patterns beyond 5/8th of a wavelength.

So the only way to reliably install a vertical and dispense with any worries about SWR and power handling is to build a mono-bander.

Regulars will know that I’ve been playing with the idea of adding separate elements to a 40m vertical mono-bander to add in the odd frequency, say 20m – but the interaction between elements can cause impedance issues (read SWR).

With development, I’ve discovered the optimum spacing between elements to achieve pure quarter-waves on 40m, 30m, 20m, 17m and 12m. It happens that the 40m vertical will resonate on 15m for excellent very-low radiation patterns and with the addition of a shorter-then-normal 10m element (around 2.6m in length) one can get radiation with a regular quarter-wave pattern, although the idea of using a ground-mounted vertical for 10m is slightly off-putting. There are other methods to get good radiation on the 10m band.

A picture speaks a thousand words, so, without further waffling, here is the prototype in action. It uses a regular DX Commander fibreglass pole which is around 9.7m in length with stainless hose-clamps using 8mm ID aquarium tubing (softened in hot water to push over the clamps). These clamps don’t scratch the tubing and securely hold each section from slipping down in a gale.

 

The base plate (radial plate) in the prototype is an aluminium angle with an SO239 fitted. The centre conductor is soldered with added heat-shrink and flooded with hot-glue. Connectors are used to connect to what I’m calling the “driven” plate with stainless nuts. RF enters the driven plate and self-selects the band it wants, just as a fan-dipole would. A guying point made from Nylon 66 keeps the elements optimally spaced as well as securely hold the mast upright at 1.2m off the ground to three guy stakes.

At the 5m point, a “spreader” plate houses the 20m and 17m elements on 3mm bungee cord with the 30m and 40m elements passing straight through. At the time I took the pictures, I had dispensed with the 15m and 12m elements.

In operation, I achieved better than 1:1.5 SWR across the operational bands selected. It was fun leaving WSPR mode running and allowing it to change bands without any ATU etc.

This antenna will comfortably handle 5000 Watts, although of course, the author only ran 400W RTTY for long periods for practical testing.

Hand-production of this system is extremely time-consuming so I am about to launch this with slightly lighter-weight and machined components to reduce cost. Target consumer price will be around £99. You’ll just need to add the wire and follow the instructions.

If you’d like to stay informed about progress, let me know.

I’ve just had an interesting discussion on 40m this evening with Peter, OH6GHI, also an antenna enthusiast. I happened to mention that I was listening to him on both VFOs. VFO A on my dipole and VFO B on my vertical and I found the stereo image very interesting as the polarisation of his signal to me changed.

half-square-basic-designWe got talking about half-squares and I confirmed that we were talking about the same thing, basically 2 x 10m verticals separated by a 20m top section. The half square is fed in one corner and according to my MMANA model, this should present 50 ohms and a great SWR curve across the whole of 40m.

(read more…)

I switched on the other evening and heard a very quiet DX caller on 7.142. It was YC0LOU from Indonesia and I could only pick up parts of his call. He called and called and had no takers. In fairness, he was extremely quiet but as the sun was gradually moving around the sky, he finally became audible and it was worth giving him a shout. 400w off my inverted V at 7m height got his attention but I needed a few blasts for him to get my call right. I put him on the cluster and he had a pile up.

Now, the point is, had I had more gain, I’d have not only heard him better, but he’d have heard me quicker too.

So I could add more height to my Inverted V but the difference between 7m and 10m isn’t actually that much at 5 degrees off the horizon – not even a db. Hardly worth writing home about.

40m-wire-yagi-drawingAnyway, this was the QSO that made me sit up and take stock of what I could do. I was seriously considering phased verticals for DX when I thought up the idea of having a switchable wire yagi. Either firing East or firing West.

Like me, you may already have an inverted V dipole up for 40m, all you need to is build another one about a quarterwave in front – or behind your existing dipole but out of a single wire. You don’t need to feed this with coax, it’s a parasitic element, like a 2 element yagi.

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palstar-at4kHaving recently taken delivery of a Palstar AT4K manual tuner, I was keen to get her into production to replace my CG5000 in the attic.

Problem: the route to the attic from the shack is complex but I have a number of spare coax runs going that way including a couple of RG58 cables that I installed about 10 years ago as backups. Actually I originally installed three RG58 lines but I’ve been using one of them to send 12V up the line to the ATU.

parallel-cox-to-ladder-lineAfter MUCH research, I finally used about 20 feet of parallel coax feeders, connecting ladder line to both ends. To clarify, I run about 12 feet of ladder line from the ATU to the parallel RG58 cables. I soldered the ladder line to the inner core of the RG58 coax and shorted the braid-to-braid. My 20 feet of RG58 runs to the attic, through walls, up ceilings etc and in reverse, I connected the ladder line to the RG58. Again, I shorted the braids of each line to each other with a solder blob. My ladder line then has another run to the feedpoint of a large 60m loop that runs through the attic and around the garden.

The results have been quite amazing. Comparing my 40m reference dipole to the the CG5000 (SG230 type) ATU feeding the 60m loop has always shown that the loop was about an S point lower than my reference dipole for most stations.

(read more…)

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).

quarter-vs-three-quarter-wavelength-vertical-antenna-plot

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

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The A3S is 14Kg (That’s 30 pounds in US money :) )

I was worried that the combined weight of a Create Rotator an aluminium pole *and* DSC_0106an A3S Cushcraft might be too much for my little lighting rig.

To test it out, I fitted the Create Rotator to the mast and added a 20Kg dumb-bell weight and started the motor.

It lifted without an issue so I’ll go ahead and plan to use the A3S for next field day.

How mad is that? !

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.   (read more…)

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.

60-foot-mast-featured-image

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.   (read more…)

This is actually three separate dipoles connected to one feepoint

I love engineering challenges and I needed an elegant solution to mount a vertical antenna right on the corner of my house.
In the end, I used 3 x 24 inch T brackets from Barenco Antenna Hardware store. Poor Brian (Barenco owner) was a little confused by my request but he dispatched my order all the same and I’m pleased with the results.

By the way, a little tip. Don’t use those RawPlug type anchor bolts, they expand and they are tightened and could break off the side of the brick, particularly right on a corner. Instead, use Multi-Monti bolts. These cut a thread inside a pre-drilled hole. The beauty of Multi-Monti bolts is that you can remove them and re-install them at will. If you want to fill in the hole afterwards, use Frame Mastic from ScrewFix (or similar). You will never know your aerials were once there.

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15m and 10m fan dipole arrangement test

They used to call this the “AT&T Wiremans Join” but frankly, it’s the best way of joining wire together anyway. If you are joining insulated wire, first strip away about an inch of insulation of both ends.

If you have stranded wire, twist the strands on each wire together and solder them into a single fat strand.

DSC_0217

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