K5D - Desecheo Island

Originally posted on 'The wet string chronicles' in May 2009. 

The very smart K5D QSL card

The QSL card arrived today and a very nice card it is, befitting the dxpedition itself which was a slick, well run affair.

I was very pleased with my 30m CW contact because prior to the night I made the contact I’d struggled to hear them at all. Add to that the huge pile-ups I was convinced I’d never get through. But, on the night of the 22nd February 2009, they were much louder so I set about making a few calls, trying to find my way through the pile-up. Half an hour later they were in the log.

I’ve had some good successes on morse code over the past year or two with VP6DX and K5D as two contacts of note. I next hope to work El Salvador for an all time new one later this month when a British team will be operating exclusively on CW as YS1G. Fingers crossed there is some decent propagation come the time.

G0RIF portable from Barr Beacon

Originally posted on 'The wet string chronicles' in May 2009.

Just a few words on todays operation from Barr Beacon (IO92BN) when I setup on 20m with the Par End Fedz 20m dipole suspended vertically on a 10m fibreglass pole.

Band conditions weren’t great and there was fast deep fading. Not as bad as 17m at the weekend but still pretty dramatic. Best DX was VE1ZA/m (Tony) followed by OH0/DL9GTI (Ralf). It seems Ralf wasn’t the only German out and about as I also worked Peter in Croatia as 9A/DL4KM/p and Charlie in Italy as I/DL3KHK. In keeping with this ‘operating abroad’ theme I also worked Dave in Menorca as EA6/M0DLL.

All in all it was an enjoyable few hours on 20m when even the weather was pretty good…until the battery was run down and I’d packed everything away, after which it poured it down. I think I timed that perfectly! 

QSL cards received this week from 6Y1V and KL7RA

Originally posted on 'The wet string chronicles' in December 2009. 

KL7RA and 6Y1V QSL cards

Here we have a few interesting cards received this week for contacts in the CQWW CW contest in November (6Y1V) and the CQWW WPX CW contest back in May (KL7RA). Both of these are in response to direct QSL requests.

Alaska (KL7RA) was an all time new one for me at the time so it’s nice to get that confirmed for number 153 (of 170) confirmed by paper QSL.

6Y1V (on 40m) was a highlight on the recent CQWW contest and I had a pretty quick response via the QSL manager in Finland (Kari, OH3RB) which was nice. The card also confirms a 20m and a 40m contact from the WPX CW contest in May.

In other news, SpaceWeather.com reports that sunspot 1035, having burst onto the scene 3 days ago, continues to grow and is crackling with C-class solar flares with a chance of M-class flares.

CQ contest: Starting your contesting journey

Radio contesting, or "radiosport," is a popular way for amateur radio operators to test their skills, equipment, and strategy by making as many contacts as possible in a set period. 

I enjoy contests because it usually means that the bands are alive with lots of nice DX and as much as I don't keep score or submit logs, I do like to make as many contacts as I can during each contest just to make the most of the elevated levels of activity to be enjoyed at these times.

CQ World Wide WPX (CW 2009) - my 52 countries worked during the contest

However, if you want to take contesting more seriously, for operators in the UK, there are several routes into contesting, each offering unique experiences and learning opportunities.

1. Participate in RSGB weekly contests

The Radio Society of Great Britain (RSGB) runs a variety of contests that are perfect for beginners. These include HF contests like the RSGB 80m Club Championship and the UKAC (UK Activity Contests), which are held on different HF, VHF, and UHF bands throughout the month. VHF and UHF contests are particularly accessible to those with basic equipment and smaller antennas, as they typically involve shorter-range communication, making them ideal for operators in urban areas or with limited space. Participating in these contests allows you to familiarise yourself with contesting procedures and improves your operating skills in a structured, yet relaxed environment. The RSGB also provide a lot of useful information here: https://rsgb.org/main/radio-sport/radcom-contesting/

2. Join a local Amateur Radio Club

Many local amateur radio clubs in the UK have active contesting groups. By joining a club, you can benefit from the collective experience of seasoned contesters and access to club equipment, which may be more advanced than your own. Clubs often participate in RSGB contests as teams, which is a great way to learn from others and get involved in the community. Clubs such as the Drowned Rats Radio Group and the VHF Contest Club are known for their participation in VHF and UHF contests, providing opportunities to operate in a group setting and learn about different aspects of contesting.

3. Engage with online contesting communities

Online communities and forums provide valuable resources for new contesters. Websites like the RSGB Contest Committee's site offer detailed information about upcoming contests, rules, and results. Engaging with these communities allows you to ask questions, share experiences, and gain insights from more experienced operators. The UK Contest Reflector and the VHF Contest Forum are popular places where UK contesters discuss strategies, share tips, and organise activities.

4. Explore VHF and UHF contesting

Contesting on VHF and UHF bands provides a different set of challenges and opportunities compared to HF contesting. These bands are affected by different propagation modes, such as tropospheric ducting and Sporadic-E, which can lead to surprising long-distance contacts. VHF/UHF contests often have a regional focus, making them accessible to operators with basic equipment. Participating in these contests helps you understand the nuances of these bands, such as the impact of terrain and the importance of antenna height and gain.

5. Contest Logging Software

Effective logging is essential for successful contesting. Contest logging software, such as N1MM Logger+ or Win-Test, is widely used to track contacts, score accurately, and manage log submissions. These tools are particularly useful in contests that involve rapid exchanges and numerous contacts, as they help prevent duplicate contacts and errors. Familiarising yourself with logging software will improve efficiency and accuracy, making the whole contesting experience more enjoyable.

For more information, visit http://www.contesting.com and follow the links in the “New to Contesting?” section.

At last, an antenna that works!

Originally posted on 'The wet string chronicles' in April 2009. 

Last night I put up an antenna for the 6m (50MHz) band. I built the antenna several weeks ago to a design I found online - the antenna is called ‘the mighty wide 6m dipole’ (by Brian, G0IER). The ‘mighty wide’ bit refers to the bandwidth of the antenna. The broadband nature of the antenna is desirable due to the width of the 6m band, a full 2MHz.

Once built and tuned this antenna exhibits a flat SWR plot across the whole of the 6m band. I used the antenna for the first time tonight and had a lengthy chat with Richard (M0SNR) down in Castle Bromwich. Running just 20 watts output he gave me a good readability 5, strength 8 report.

The antenna is deployed in a stealth configuration running along the top of a 6 foot high storage unit in the top bedroom. The good news is, it works!

My first experience with the Reverse Beacon Network

The amateur radio Reverse Beacon Network (RBN) is an innovative system that has revolutionised how ham radio operators monitor and analyse radio propagation. Unlike traditional beacons that transmit signals for others to hear, the RBN uses a network of automated listening stations around the world to detect and report amateur radio transmissions.

These listening stations, often called "skimmers," employ clever software that continuously monitors multiple amateur radio bands. When they detect a CQ call (or other transmission that they recognise), they report the signal's frequency, strength, and other characteristics to a central database. This information is then made available in real-time to radio enthusiasts and researchers worldwide via the internet.

The RBN provides valuable data for understanding radio propagation conditions, helping operators determine which bands are open for communication and where their signals are being heard (in much the same way as PSKReporter does with digital mode transmissions). It is particularly useful for contesting, DXing (long-distance communication), and studying the effects of solar activity on radio transmissions.

Since its inception in 2009, the RBN has become an essential tool in the amateur radio community, enhancing operators' ability to make contacts and contributing to our understanding of radio wave propagation. 

Being somewhat late to the RBN party (due in large part to my extended periods of inactivity), my first use of this facility was yesterday (23rd August 2024) when I was setting up an automated CW keying interface between my computer and Xiegu G90 radio.

Having established that my keying interface was working, I tuned up and down the lower end of the 15m band and I heard not a single CW station. Granted I was only using a 1/4 wave vertical antenna and conditions weren't great at that time of day, but I was a bit surprised to hear nothing. 

This led to my putting out a succession of CQ calls (5w output, with no responses) to see if (or where) I might be heard by the receiving stations of the reverse beacon network. Within a minute or two I was seeing RBN spots for my signal received as far away as the east coast of America (where I suspect their antennas were doing much of the heavy lifting) and Asiatic Russia, as shown on this screenshot I took at the time.

RBN spots for my 5w CQ calls

Tools like the RBN and PSKReporter are very useful tools when it comes to gauging propagation from your location because they provide real time feedback of exactly where your transmitted signal is being received, and from where you might expect a few replies if you put out a few CQ calls. I will certainly be using the RBN a lot  more in the future.

Radio:  Xiegu G90

Antenna:  1/4 wave vertical

Power:  5w

Location:  Lichfield

Instant [well nearly] QSL with eQSL

Originally posted on 'The wet string chronicles' in December 2009.

eQSL from YW4D, Venezuela, 40m CW

I’ll begin by saying first of all that not all amateurs look on the eQSL concept favourably. Many see it as open to abuse and as a consequence many awards bodies do not accept an eQSL (or ‘electronic QSL’) as confirmation of a contact. OK, that’s that out of the way.

Having said that, many amateurs do use them. They’re cheap (free in their basic form) and they’re quick. This 40m CW eQSL for instance is for a contact made only 2 days ago in the CQWW contest.

I like to save the more interesting eQSL images and use them as a screensaver on my PC (mixed in with scans of my paper QSL cards). Even though they’re not admissible for awards, I know they represent contacts I made and as such they’re as much a reminder of a contact as any paper QSL.

Given it’s a free service (unless you choose to contribute) I think it’s a really worthwhile service for those hams who have neither the time nor funds to QSL by other means. Check them out at eQSL.cc.

Top 10 essential items in your POTA/SOTA go-bag

When preparing for a portable amateur radio operation, whether it's a SOTA (Summits on the Air) activation, a POTA (Parks on the Air) outing, or simply a day of fieldwork, packing the right gear is crucial. 

Balancing weight with functionality ensures you have everything you need without being bogged down by unnecessary items. 

Here’s my list of the top 10 essential items to include in your portable operation go-bag:

1. Portable transceiver

Your transceiver is the heart of your portable setup. Opt for a lightweight, compact model like the Yaesu FT-818, Icom IC-705, or Xiegu G90. These radios offer a good balance of power, band coverage, and portability, making them ideal for field operations.

2. Antenna system

A versatile, lightweight antenna is a must. Consider a linked dipole, multiband EFHW (End-Fed Half-Wave) antenna or a compact vertical antenna. These antennas are easy to deploy and can cover multiple bands, making them perfect for portable operations.

3. Power source

Choose a reliable, portable power source like a lightweight LiFePO4 battery. These batteries provide ample power for extended operations and are lighter than traditional lead-acid batteries. Don’t forget a small solar panel if you plan to stay out for longer periods.

4. Antenna tuner

If your radio lacks an internal ATU, an antenna tuner ensures you can use your antenna on multiple bands efficiently. Compact tuners like the Elecraft T1 or LDG Z-100Plus are great choices for portable use, offering good performance without adding much weight.

5. Coaxial cable

A quality coaxial cable is necessary to connect your antenna to the transceiver. RG-174 is a popular choice for portable operations due to its lightweight and flexibility, though you may opt for RG-58 if you need lower loss over longer runs.

6. Morse key/paddle (if operating CW)

For CW enthusiasts, a lightweight, portable Morse code key is essential. Compact paddles like the Begali Traveler Light or Palm Radio Mini Paddle are excellent choices that won’t weigh down your bag.

7. Logbook and pen

Even in the digital age, a physical logbook and pen are crucial for keeping track of contacts, especially if digital logging isn’t practical in the field. A small, waterproof notebook like the Rite in the Rain series can be invaluable.

8. Multitool

A multitool is indispensable for any outdoor operation. It can help with antenna adjustments, repairs, and other tasks. The Leatherman Wave+ is a popular choice for its range of functions and durability.

9. Headphones or aerbuds

In noisy environments, a good pair of headphones or earbuds is essential for clear communication. Choose a lightweight, comfortable pair like the Sony MDR7506 or compact in-ear monitors that block out background noise effectively.

10. Emergency kit

Always carry a small emergency kit that includes a first-aid kit, a whistle, a flashlight, and an emergency blanket. You never know when these items might become crucial during an outdoor operation.

11. Your mobile phone!

Did I say top 10? Well this list goes to 11. Your mobile phone is a great tool for finding your way and for spotting yourself if you're doing a POTA or SOTA activation. It's also very useful in the event of an emergency, on which basis it should be considered a part of your emergency kit anyway.

Packing a well-thought-out go-bag ensures that you're ready for any situation during your portable operation. By focusing on lightweight, multifunctional gear, you can maximize your efficiency and enjoyment while keeping your load manageable. Happy DXing! 

An efficient 5 band random wire antenna (40-15m)

Tackling the challenge of a multi-band random wire antenna for 40m through 15m, I pondered which length of radiating element would find that sweet spot where efficiency meets directivity across 40/30/20/17 and 15m bands.

First, I considered the fundamental resonant lengths for each of the bands:

• 40m: ~66 feet
• 30m: ~47 feet
• 20m: ~33 feet
• 17m: ~27 feet
• 15m: ~22 feet

Comparison of radiator lengths for multi-band end-fed antenna

Knowing that a non-resonant antenna can still perform well, I started calculating harmonics and looking for common multiples. A length of 68 feet emerged as a promising candidate - long enough to be efficient on 40m while providing harmonic resonance on the 20m and 15m bands..

This looked like it should provide:

• A good match on 40m with a low takeoff angle
• Decent performance on 30m with acceptable SWR
• Strong lobes on 20m, nearly full-wave resonance
• Workable patterns on 17m and 15m, though with some compromise

While not fully resonant on all bands, the 68-foot length works well with a 9:1 unun, offering a reasonable SWR on all bands and a good match for an antenna tuner, allowing for efficient operation across the desired bands. This flexibility is particularly useful as I hope to use this single antenna for multiple bands without frequent adjustments.

Next, I considered antenna orientation and decided on a northwest to southeast layout to maximise my desired coverage. This orientation should then give me:

• Good low-angle radiation on 40m for DX work
• A nice figure-of-eight on 20m covering both Europe and the Pacific
• Acceptable compromise patterns on 30m, 17m, and 15m

Further research suggested that a slight inverted-V configuration would provide the added benefit of bringing the feedpoint impedance closer to the unun's sweet spot on several bands meaning that the predicted efficiency ranged from excellent on 40m and 20m to acceptable on 15m, with 30m and 17m falling somewhere in between.

I'm confident that my chosen length of 68 feet will allow me to get most out of this simple yet effective antenna design and achieve my personal objectives. Of course, the real test will come with on-air performance so now it's time to start unspooling wire and see if the ionosphere agrees with me. Wish me luck!

RSGB Commonwealth Contest 2009

Originally posted on 'The wet string chronicles' in March 2009.

The RSGB Commonwealth Contest, for those of you who aren’t amateur radio operators, is a 24 hour morse code contest where the aim is to contact as many stations as possible in countries comprising the British Commonwealth.

I’d been looking forward to this for a while having done well last year in so far as I managed to work 4 all time new ones over the 24 hour period. This weekend however was a bit of a disappointment with most stations of interest either not heard at all or way down in the noise.

I don’t think conditions were great but I attribute the disappointment mostly to my relatively poor antenna compared to last year. My 2008 efforts from a previous residence were assisted by resonant 20m and 40m dipoles. This year at a new QTH I am using a simple random length wire tuned by an antenna tuning unit. This makes for a far less efficient receive and transmit antenna. I think it’s time to explore how I can fit some resonant antennas into my new setup. 

Dipole or doublet? What difference does it make?

When it comes to amateur radio operation, choosing the right antenna can make all the difference between a satisfying QSO and a frustrating time spent fiddling with knobs on your antenna tuner. For the everyday ham, two popular options are the humble dipole and the versatile doublet. On the surface, very similar antennas, but let’s dig deeper.

The simple dipole: 'Old Reliable'

The dipole is the old standby for many hams. A single wire cut to half a wavelength at your desired frequency, fed in the center, and raised as high as your mast (or a convenient tree) allows. It’s simple, it’s effective, and it requires no special skills or knowledge to construct. A well-tuned dipole will give you a decent match without the need for an antenna tuner. The dipole’s figure-eight radiation pattern does a respectable job of putting out a signal in two broad directions. 

For a single-band setup, or even for multiband use with some wire length adjustment (such as a linked dipole or trap dipole), the dipole is a reliable workhorse.

But like any workhorse, it has its limitations. The dipole’s resonance is narrow, and moving far from the design frequency can lead to a rapidly rising SWR. Sure, you can use a tuner to broaden its usability, but at the end of the day, a dipole is best when it’s in its comfort zone, i.e. it's design frequency.

The Doublet: The 'Swiss Army Knife' of antennas

Enter the doublet, the dipole’s more sophisticated cousin. At first glance, a doublet might look a lot like a dipole, but its magic lies in its flexibility. The doublet is usually a bit longer than a resonant dipole, often around 88 feet for multiband use, and is typically fed with ladder line or an open wire feeder instead of coax. This setup allows the doublet to operate effectively across multiple bands with the aid of a good antenna tuner.

Unlike the dipole, the doublet isn’t a one-trick pony. Its radiation pattern changes with frequency, which can be both a blessing and a curse depending on your operating preferences. On the lower bands, the pattern is similar to a dipole, but as you move up in frequency, the doublet begins to show multiple lobes, offering a wider array of radiation angles and sometimes even surprising you with unexpected DX. However, this also means that the doublet’s performance can be less predictable and may require more fiddling with the tuner to get the match just right, or with the orientation to get those lobes pointed in the preferred directions..

Which to choose?

If you’re a fan of simplicity and operate primarily on a single band, the dipole is hard to beat. It’s easy to build, easy to use, and gets the job done without fuss. But if you crave flexibility and don’t mind a bit of fine-tuning, the doublet offers a level of versatility that the dipole can’t match. For a ham who enjoys working multiple bands from 40m down to 10m without needing multiple antennas, the doublet might just be the better choice.

In the end, it’s about what you value most in your shack. Whether you stick with the reliable dipole or experiment with the adaptable doublet, there’s no wrong answer—just different paths to the same goal: making that QSO by getting your signal out and being heard.

Is FT8 killing amateur radio?

I found an interesting opinion piece article on this topic by KE8FMJ on the DX Engineering 'On All Bands' blog site titled 'FT8: Saving or Destroying Ham Radio?', and it got me to thinking about my views on this mode.

A snapshot of FT8 signals received

For me, this mode has a lot to offer and is in large part why I have recently resurrected my amateur radio hobby after several years of inactivity. FT8 in combination with small, portable, inexpensive radios like the Xiegu G90 (which I own) now means that with minimal expenditure I am able to work lots of DX with a very modest station. 

Granted, being close to the peak of solar cycle 25 is helping...a lot...but the weak signal capability of FT8 is a real advantage for us little guys, and increasingly so as cycle 25 tails off over the next few years.

So yes, I am a fan of FT8, as much as I can appreciate how it might irk the traditionalists who prefer more of a personal touch to a QSO, or the need for greater effort and skill to snag some nice DX. I too love those aspects of amateur radio and enjoy nothing more than tuning across a quiet band and hearing a faint signal, and then working them with my compromise antenna. I do believe though that there is room for all of that, and more, as amateur radio evolves, as it surely must, and will always do.

Coincidentally, it was another new digimode that gave me reason to get back into amateur radio back in 2005 when PSK31 came to my attention. That particular mode led to many contacts on all bands from 40-10m and eventually led to my interest in RTTY which quickly because my favourite mode of operation.

Based on my personal experiences then, you could make the case that the continuous evolution of amateur radio, and new modes of operation (perhaps with greater appeal to a more technology savvy generation) are a very real driver for the introduction of new hams to this wonderful hobby, and to resurrect the hobby for a few older lapsed hams such as myself.

In summary, FT8 gets my vote as a worthy addition to the hobby. I hope to make the most of this mode, and others, for as long as cycle 25 provides QRP friendly propagation on the HF bands.

Yaesu FT-897 - first impressions

Originally posted on 'The wet string chronicles' in March 2009.

My FT-897 (purchased second hand) arrived about a week ago but was only used on receive for the first few days while I got the hang of the menu system and sorted out a new power supply. Out of the box I have to say that the pictures don’t do this radio justice.

Granted it’s what’s on the inside that really matters but it doesn’t hurt if a radio looks good on the desk. To that end the FT-897 is a good looking radio!

Hello Yaesu FT-897!

In use I have found the menu system simple enough but if you’re used to a more sophisticated user interface you may find some of the key presses required to effect a change in the radio’s setup to be a little bit long winded. My other radio is a Kenwood TS-480SAT and that radio has a very nice user interface - by comparison I am finding the Yaesu FT-897 to be a bit cumbersome.

Receive performance on HF is good and the radio does benefit from audio DSP noise reduction. This does significantly quieten what is otherwise a pretty noisy receiver. There is also DSP bandwidth filtering which is effective in reducing adjacent channel interference to allow the desired signal to be better heard. This was put to particular use in the CQWW WPX SSB contest this past weekend. The receiver seems to cope quite well with crowded band conditions, although it should be noted I do have the W4RT 2.3KHz Collins SSB filter installed which no doubt helps in that regard.

By way of comparison I would say that the FT-897 is not as good as the TS-480 on HF receive but that should come as no real surprise as the TS-480 is HF+6m only and is designed for optimal HF performance. The FT-897 on the other hand covers HF+6m plus 2m and 70cm. The difference is hard to quantify and I couldn’t hear anything on the Kenwood that I couldn’t on the Yaesu - it’s just that the Kenwood seems more in control of the received signal and has better recovered audio than the FT-897.

I can’t say much yet about the transmit performance - I need a few on-air reports to compare a few settings before passing judgement. I hope to be able to conduct those tests in the next few weeks - I’ll report my findings then.

Overall, given its design intent, the FT-897 is in my opinion a very good radio. It seems to have ticked all the right boxes and arrived at a good compromise in terms of size, frequency coverage, operator convenience and performance.

I am now looking forward to taking the radio out into the field for some portable operations and antenna experimentation. Until then I’m enjoying using the radio in the shack where it is used for HF SSB, 2m and 70cm work while the TS-480 handles all other HF modes like CW, PSK31 and RTTY (and other digimodes).

In summary then, given what it sets out to achieve, I have to rate the Yaesu FT-897 a very good radio and one I look forward to owning and using for many years. 

A very quiet afternoon on 20m FT8

I had a quiet Saturday afternoon in prospect so set about getting on the radio for a few hours to see what I might work on 20m RTTY. My setup was such that I wasn't expecting much but I was surprised just how little I actually found. 

Using the Airlink Express software for AFSK RTTY connected to my Xiegu G90 and a shortened loaded vertical,  I heard not a single RTTY station on 20m. Zip, nada, nothing! I checked spotting websites for 20m RTTY activity but saw nothing for today although there were a few (and I mean only a few) spots for yesterday, the 9th. Now I realise that my antenna is a significant limitation but I'd expected to hear something, even if they may not have been able to hear me, but no, nothing at all.

I then tuned up and down the CW band segment to see what I could hear there. Again, very quiet, although I could hear some weak signals at times. The loudest station I heard was a Portuguese station calling CQ contest, and there were stations calling him but they too were quite faint with me.

I tried the same up and down the phone segment of the band which was also very quiet with a long Slovenian station calling CQ content with only very few replies in the time I was listening.

Right I thought, FT8, there'll be plenty of activity on there. And there was...but it was clear from the waterfall display in JTDX that there was deep fading (which might be a consequence of some form of variable blanketing or absorption) affecting signals. I'd see a band full of signals one minute, only to be presented with a largely blank waterfall a few minutes later. This meant that there were precious few decoded signals to be seen in the 'Band Activity' window. 

I managed to work a handful of stations on 20m (in Spain, Norway, Italy, Portugal, Germany, Finland, Ukraine, Poland and Denmark) and I worked one Italian station (IK2ZJP) on 17m in a brief foray to see what propagation was like on that band (it was just as bad).

Meagre pickings on 20m FT8	PSKReporter showing my 20m spots

I checked PSKReporter to see just where I'd been heard and what it showed was that the propagation on 20m was very much favouring continental Europe and Scandinavia, consistent with my experience on the band. In a way it was reassuring to see that it was just poor conditions that I been battling instead on anything inherent in my simple setup. I'll certainly be trying again before too long to see who's out there and to what extent the propagation gods are favouring us and hoping for better luck next time.

Radio:  Xiego G90

Antenna:  Loaded vertical for 20m

Power:  10w

Location:  Barton under Needwood

NVIS antennas for effective regional communication

Near Vertical Incidence Skywave (NVIS) antennas are an interesting yet often overlooked asset in a ham operator's toolkit. They’re designed to boost communication over short to medium distances, typically within 0-400 miles. For regional communication, getting the hang of NVIS can really elevate your game.

What is NVIS? 

Typical NVIS close-in coverage

NVIS works by sending signals almost straight up into the ionosphere, which then bounce back down, covering an area starting close to you and spreading outward. This is handy for getting past obstacles like mountains or buildings that might block ground waves.

Frequency Considerations

NVIS works best on lower HF frequencies, typically between 2-10 MHz. The most commonly used amateur bands for NVIS are 80 meters (3.5-4.0 MHz) and 40 meters (7.0-7.3 MHz), although during periods of low solar activity, even 160 meters can be effective for NVIS communication.

NVIS Antenna Designs

1. Low Dipoles: A simple dipole mounted at 1/4 wavelength or lower above the ground can function as an effective NVIS antenna. For 40 meters, this means a height of about 33 feet or less.
2. Inverted V: Similar to a dipole, but with the ends sloping downwards. This configuration can be easier to set up with a single support.
3. Loop Antennas: Horizontal loops mounted low to the ground can provide excellent NVIS performance.
4. Field-Expedient Antennas: In portable or emergency situations, even a simple wire laid on the ground or suspended just a few feet high can work for NVIS.

Advantages of NVIS

1. Consistent Coverage: NVIS provides reliable communication within its coverage area, regardless of terrain.
2. Low Power Effectiveness: Due to the short skip distances involved, NVIS can be very effective even with low power transmitters.
3. Reduced Interference: NVIS signals typically don't propagate far beyond the intended coverage area, reducing long-distance interference.
4. Ideal for Emergency Communications: NVIS is excellent for regional emergency networks where reliable communication is critical.

Implementing NVIS in Your Station

To dive into NVIS, try lowering your existing wire antennas. For instance, if you’ve got a 40m dipole up at 60 feet, put up another at around 20 feet and compare the two for regional contacts.

For portable ops, a simple wire dipole or inverted V at a low height, like on a mast or even in trees, can be set up quickly for solid regional communication.

In summary...

NVIS antennas are a great choice for amateur radio operators wanting to boost their regional comms. By grasping the basics and trying out different setups, you can greatly enhance your local area connections, whether for casual chats, nets, or emergency use.

Suspicions confirmed!

Originally posted on 'The wet string chronicles' in March 2009.

I need a better antenna. This weekends BARTG (British Amateur Radio Teletype Group) RTTY contest was a major disappointment. As with the RSGB Commonwealth contest last weekend, significantly fewer stations were heard than last year and countries that were easily worked last year on my old antenna are hard work or not possible this year.

Another increasingly apparent flaw in my current antenna setup is the amount of RF in the shack. ‘RF in the shack’ is when radio frequency energy (radio waves) is picked up by equipment in the shack making them ‘hot’. Touching something that is ‘hot’ with RF is something between an electric shock and a burn - not a nice sensation. Not at all what you want when you’re holding bits of the equipment like, for instance, a microphone.

The thinking now turns to how best to install something better given the severe restrictions on just what can be erected. Time to get my thinking head on… 

Kosovo - DXCC or not DXCC? That was the question.

Originally posted on 'The wet string chronicles' in May 2010.

The eagle eyed reader might notice a few discrepancies in the total number of countries (DXCC entities) I have worked - I had previously claimed 177 countries but I have recently revised that downwards by removing Kosovo from the list. My total is now accurately stated as 176 countries worked.

Last year (2009) a number of stations operated from Kosovo with YU8 prefixes as speculation grew as to some form of Kosovan breakaway from Serbia. There was some discussion at the time as to the validity of these callsigns and the likelihood that Kosovo would eventually be recognised by either or both of the ARRL (who run the DXCC program) and the international community. Mindful of the ‘work them now, worry about it later’ maxim I logged any YU8 stations I worked at the time as Kosovo, just in case.

However, things didn’t happen in line with the speculation and in the course of tidying up my log I have recently amended all of those contacts to be Serbia. Just in case anyone was wondering how or why I’d ‘lost’ a country. 

HF Transceivers for the antenna-challenged ham (Pt.2)

There are several other radios, both older and newer models, that could be suitable alternatives to the IC-7300 and FTDX10 (you can find my earlier post on this topic here: 'Choosing a HF Transceiver for the antenna-challenged ham') for an antenna-compromised operator. Here are a few options to consider:

1. Kenwood TS-590SG: Although an older model, it's renowned for its excellent receiver performance and good DSP capabilities. It's often praised for its ability to pull weak signals out of the noise.
2. Elecraft K3S: While more expensive, this radio is known for its exceptional receiver performance and flexibility. It's a favorite among DXers and contesters.
3. Yaesu FT-891: A compact, affordable HF+6m transceiver with good receiver performance, digital noise reduction, and digital notch filtering, which can be very helpful in pulling weak signals out of noise - a common challenge for those with compromise antennas.
4. Yaesu FT-991A: This all-mode, multi-band transceiver offers good performance and versatility, including HF/VHF/UHF coverage.

Elecraft K3S

Yaesu FT-450D

5. Icom IC-7200: An older model, but known for its rugged build and good receiver. It's a simpler radio but still offers good DSP features.
6. Yaesu FT-450D: Another older model that provides good performance and a built-in antenna tuner, which can be very helpful with compromise antennas.
7. Icom IC-705: While QRP, its excellent receiver and portability make it a good option for those with severe space constraints who might need to operate portable occasionally.
8. Expert Electronics SunSDR2 Pro: A less well-known option, but it offers excellent SDR performance that can be beneficial in challenging antenna situations.

Each of these radios has its strengths and might be more or less suitable depending on the specific needs and constraints of the operator. The older models might lack some of the newer features but often provide excellent value for money, especially on the used market. The newer models generally offer more advanced DSP and filtering options that can be particularly helpful for antenna-compromised situations.

Jamaica confirmed (6Y8XF)

Originally posted on 'The wet string chronicles' in April 2009.

Nigel (G3TXF) made 2,100 CW QSOs operating as 6Y8XF from Montego Bay in Jamaica for the 2009 Commonwealth Contest. One of those, on 40m, was me.

I’d worked Jamaica many times previously but I was still waiting for a confirmed contact. I know Nigel is a serious QSLer so I was pleased to get him in the log and even more pleased when his QSL card dropped onto the mat this morning.

Thanks to Nigel Jamaica is now confirmed, this despite my earlier moans (see March 15th) regarding my poor antenna setup and performance. 

It’s fair to say that the antennas at the other end more than made up for my bit of wet string - check out Nigel’s excellent site at http://www.g3txf.com where he has a write-up of his Jamaican trip and some nice pictures of the station he was using.

I also had a QSL card this week from PJ5NA (James) on Sint Eustatius Island in the Dutch Antilles. I was really pleased about this one because it was a very difficult 30m CW contact on a very noisy band. But it seems I got him and it’s one more to the confirmed total - now running at 165 worked, 144 confirmed (by QSL card), 148 total confirmed (I also use ARRL’s Logbook of The World where my total stands at 105 confirmed). 

Whatever happened to 'The wet string chronicles…' ?

‘The wet string chronicles…’ was the title of a Wordpress blog I ran until about March 2011, so called because of my less than optimal amateur radio antenna. Over the years I’ve always used simple wire antennas, some of which have worked better than others. 

'The wet string chronicles' c. 2010

Some of my less performant antennas are, what we in England would say, ‘about as much use as a bit of wet string’! In antenna terms it’s colloquial for ‘a not very good antenna’.

Today, as I was browsing the internet, as we often do, I stumbled across a dead link to a review I wrote on the Yaesu FT-950 radio. I tried to find this old webpage on the Wayback Machine internet archive, and lo and behold, there I found substantial remnants of an old Wordpress blog of mine!

Since that lucky find I have been rummaging through the remains of my old blog with a degree of nostalgia and a smile on my face as I have read long forgotten blog entries about amateur radio, and other things. All great reminders of a different time in my life.

As I dig though my old blog I will copy anything amateur radio related to re-post here. 

PS: I did eventually find that old FT-950 review I was looking for. :)

Recently reposted from 'The wet string chronicles' :

A new dawn: Reigniting my passion for amateur radio

Since I was first licensed in 1991 I have sadly had two extended periods between then and now when I was not actively involved in this wonderful hobby. I was QRT from around 1994 until September 2005 and then again from April 2015 until January 2024, a total of around 20 years (out of the 33 years that I have been licensed) that I was not actually involved with amateur radio. 

A YouTube source of inspiration for me was Walt (K4OGO)

As I write this in August of 2024 I very much hope that further lengthy periods of inactivity will be avoided. To that end I am very much aware that I need to do everything that I can to get involved in the hobby instead of looking in from the outside (through the medium of YouTube) and watching everyone else enjoying the hobby.

What I have seen though is that I am not alone in reactivating my interest in amateur radio. 

As the hobby has evolves, so too do people who may have been inactive find new aspects of the hobby that interest them. In my case it was new small portable radios (I have a Xiegu G90), FT8, and portable operating with end-fed vertical wire antennas.

Having given it some thought, here are some steps I or others can take to progress from watching all of those YouTube videos, to active participation:

1. Dust off your old equipment: If you still have your old gear, give it a good once-over. Check for any obvious issues, replace old capacitors if needed, and test it out. Even if it's not cutting-edge, it'll get you started.
2. Join local clubs: Look for amateur radio clubs in your area. The RSGB (Radio Society of Great Britain) website has a club finder tool. Attending meetings will help you connect with other hams, learn about local activities, and possibly even borrow or try out different equipment.
3. Get on the air with what you have: Don't wait for the perfect setup. If you have a basic HF rig and a simple wire antenna, that's enough to start making contacts. Remember, a compromised antenna that's in use is infinitely better than a perfect antenna that's still in your imagination.
4. Experiment with digital modes: If you've never tried FT8 before, give it a go! You'll need a computer, a sound card interface (or a built-in sound card if your radio is newer), and the free WSJT-X software. FT8 is excellent for DXing, even with modest antennas and low power.
5. Brush up on your CW: If you're rusty on Morse code, there are great online tools and apps to help you practice. Start slow and work your way up. Remember, many CW operators are happy to slow down for you if you send "QRS" (please send more slowly).
6. Build some simple antennas: Start with an end-fed half-wave (EFHW) for multiband operation. They're simple to construct and great for portable use. Experiment with different lengths and configurations.
7. Try portable operations: Pack up your gear and head to a local park or hilltop. Portable operation is a great way to combine your love for radio with the outdoors. Start with a simple setup – perhaps a lightweight transceiver, a battery, and that EFHW antenna you built.
8. Explore RTTY and other digital modes: While FT8 is popular, don't forget about RTTY and other modes like PSK31 or MFSK. Each offers a different experience and opportunity for contacts.
9. Participate in contests: Contests are an excellent way to hone your skills and make lots of contacts quickly. Start with shorter contests or just spend an hour or two in a longer one. The RSGB runs numerous contests throughout the year.
10. Stay informed: Subscribe to amateur radio publications like RadCom (the RSGB magazine) or join online forums and groups. This will help you stay up-to-date with the latest trends and technologies in the hobby.

Remember, the key is to start small and build up. Don't feel pressured to have the latest and greatest equipment or to be an expert in every mode. The beauty of amateur radio is in the learning and experimenting. 

Above all though, just get involved in whatever ways you can, and before you know it, you might be the one with a YouTube channel inspiring other hams to get back into the hobby!

The Kenwood TS-430S: A compact 80s classic

When Kenwood introduced the TS-430S in 1984, it quickly became a fixture in many amateur radio stations. This compact HF transceiver offered a blend of features and performance that appealed to both newcomers and experienced operators alike.

The TS-430S covered all HF bands from 160 to 10 meters, including the then-new WARC bands. Its all-mode capability (SSB, CW, AM, and FM with an optional module) made it versatile for various operating preferences. The 100W output was standard for its class, providing enough power for satisfying DX work without requiring an external amplifier.

Original Kenwood ad for the TS-430s

One of the TS-430S's notable features was its dual VFOs, allowing split-frequency operation - a boon for DX chasers. The radio also incorporated a basic memory system, storing up to eight frequencies, which felt cutting-edge at the time.

The rig's compact size was a departure from earlier, bulkier HF transceivers. Measuring just 10.6 x 3.8 x 10.8 inches, it could easily fit on a small desk or be taken on portable operations. This portability, combined with its relatively light weight of about 11 pounds, made it popular among DXpedition enthusiasts.

However, the TS-430S wasn't without its quirks. The frequency display, while digital, used a fluorescent design that some found hard to read in bright light. The radio's stock filters were adequate but not exceptional, leading many owners to invest in aftermarket filters (270Hz or 500Hz for CW and 1.8KHz for SSB were available) for improved selectivity. 

Reliability was generally good, but like many radios of its era, the TS-430S could develop issues with its final amplifier transistors over time. This became a well-known repair among Kenwood enthusiasts.

Today, nearly four decades later, many TS-430S units are still in operation. Its simple, analog design makes it relatively easy to service, and its straightforward interface continues to appeal to those who prefer knobs and switches over menus and buttons.

While modern SDR-based transceivers offer more features and better performance, the TS-430S remains a capable radio for everyday HF operation. For many hams who started in the 1980s, the sight and sound of a TS-430S bring back memories of late-night DX sessions and weekend contests.

The Kenwood TS-430S may not have been revolutionary, but it was a solid, dependable transceiver that served the amateur radio community well. It represents a transitional period in ham radio technology, bridging the gap between the fully analog rigs of the past (such as the Drake TR-7 and Yaesu FT-101E) and the digital marvels of today. 

The end-fed half-wave, a versatile multi-band antenna

The end-fed half-wave (EFHW) antenna has become a favorite among hams for its versatility and easy setup. It’s great for multi-band operation with just one radiator, which is perfect for those with limited space or who need something portable.

Radiator length and band selection

The EFHW antenna is a hit with hams because it's easy to set up and works on multiple bands with just one radiator. For multi-band operation, most operators (in the UK at least) focus on the 40m to 10m bands due to space constraints. A 40m EFHW antenna, with a radiator length of approximately 66 feet (20.1 meters), can effectively operate on 40m, 20m, 15m, and 10m bands, a good fit for small gardens, typical in the United Kingdom (although they are getting smaller with each passing year, but that's a whole other story).

While 160m and 80m operation is theoretically possible, the required lengths (270 feet and 135 feet, respectively) are often prohibitive for many installations. Thus, the 40m to 10m range represents a practical compromise between performance and size.

Matching transformers: The key to efficiency

A crucial component of the EFHW antenna is its matching transformer, often referred to as an "unun" (unbalanced-to-unbalanced). This device is essential for efficient power transfer between the high impedance at the end of the wire (typically 2000-3000 ohms) and the 50-ohm impedance of most transceivers and coaxial feedlines.

For optimal performance, especially at higher power levels, the choice of transformer core material is critical. Common options include:

1. Ferrite cores (e.g., FT240-43 or FT240-52) for moderate power levels
2. Powdered iron cores (e.g., T200-2) for higher power handling capabilities

The trick here is to pick a core that does not overheat at your operating power level. You want to radiate all of that RF energy, not heat up the core! Furthermore, core saturation is a key concern when a matching transformer overheats, leading to signal distortion and potential spurious emissions. The heat can also detune the antenna system by altering the transformer's impedance ratio, affecting SWR and overall performance. 

Physical damage is a another risk, with the possibility of the core cracking or breaking, and in extreme cases, melting wire insulation. Overheating can introduce non-linearities that may cause intermodulation distortion, especially in high-power setups. Finally, as the core temperature rises, its power handling capability decreases, creating a cycle of increasing inefficiency and further heating.

 Bottom line - don't skimp on your cores!

Unun ratios

The most commonly used unun ratios for EFHW antennas are:

1. 49:1 (7:1 turns ratio)
2. 56:1 (7.5:1 turns ratio)
3. 64:1 (8:1 turns ratio)

The 49:1 ratio is often preferred as it provides a good compromise between efficiency and bandwidth. The 64:1 ratio can offer slightly better efficiency on some bands but may have a narrower bandwidth.

Counterpoise wires: To use or not to use?

The use of a short counterpoise wire in EFHW antenna systems is a topic of ongoing debate. While some operators report improved performance with a counterpoise, others find little to no benefit. A counterpoise wire, typically 0.05 to 0.1 wavelengths long at the lowest operating frequency, may help in the following ways:

1. Reducing common-mode currents on the feedline
2. Improving the antenna's efficiency, particularly on higher bands
3. Potentially lowering the SWR on some frequencies

However, the effectiveness of a counterpoise can vary depending on the specific installation and surrounding environment. Experimentation is often necessary to determine its impact on a particular setup.

Radiation patterns

The radiation patterns of an EFHW antenna vary depending on the operating band and installation configuration. Using a 40-10m EFHW as an example:

EFHW radiation pattern for typical 40-10m example

1. On 40m (fundamental frequency): The antenna exhibits a pattern similar to a half-wave dipole, with maximum radiation broadside to the wire.
2. On 20m (2nd harmonic): The pattern resembles that of a full-wave antenna, with four main lobes at approximately 45-degree angles to the wire.
3. On 15m and 10m (higher harmonics): The pattern becomes more complex, with multiple lobes and nulls. These patterns can be advantageous for working distant stations at various angles.

It's important to note that the actual radiation patterns may be influenced by factors such as antenna height, surrounding objects, and ground conditions. 

According to your location and the direction of desired operation, an EFHW antenna can be oriented to take advantage of these radiation lobes to provide optimal radiation in the desired directions.

Working through the pileup: VP6DX (Ducie Island)

As much as you might see and believe that snagging that rare DX is a function of the best radio coupled with the best antenna, I'd like to dispell that myth by relating to you an experience of mine from February 2008 when I managed to work VP6DX on Ducie Island (about 9000 miles distant).

I enjoy DXing and I enjoy the challenge of getting heard when a rare station (often a DXpedition) is working a huge pileup. With my seriously compromised antenna steup this has always been something where I firmly believe that it's not about the radio or the antenna, it's all about operator persistence and guile.

My Ducie Island experience is a case in point. I'd been looking forward to trying to work VP6DX, if nothing else because my wife's name is Dulcie, which isn't a million miles away from Ducie. It was also going to be a new one for me to add to my country count. Your reasons for chasing that particular DXpedition may vary, hihi.

At that time my radio was a Yaesu FT-950 and the antenna was a random (and I do mean random) length wire sloping from an upper floor window down to the back fence of my property. I was using an LDG AT-100 Pro antenna tuner which was able to give me a good match on most bands where I was hearing VP6DX, who were mostly audible to me on 30m and 40m CW in my early daylight hours.

I spent a lot of time listening to the huge pileup trying to sense the VP6DX operator's operating style and management of the pile. How many stations did he work on each frequency before tuning through the pile? What was the extent of the pileup? Where were the quieter spots on the fringes where I might be more likely to be heard? Through all this I would be sending my call where I thought they might be listening, trying to get that elusive contact. I have to admit that it was at times a little demoralising hearing them working station after station close to where where I was transmitting but never coming back to me. This went on for many days on both 30m and 40m with no success.

However, on the morning of the 23rd of February 2008 I got lucky. I was hanging out on the upper edge of the pile (which seemed a little smaller and quieter by this time as they neared the last few days of the DXpedition) sending my call whenever the previous QSO concluded with the usual "5nn tu". 

VP6DX online log showing my 40m CW QSO

I have to say that I was thrilled to hear the beautiful sound of "RIF ?" coming back from VP6DX. I replied with my full callsign and heard what I had long waited for, "G0RIF 5nn" to which I replied "5nn tu" and that was it, VP6DX was in the log.

I then had a nervous wait to confirm that I was in their online log before requesting a physical QSL card from their QSL manager. 

I duly received my VP6DX QSL card and this is now a precious reminders of that QSO and the time and effort that went into securing that contact. More than anything though it is a permanent reminder that no matter your radio and/or antenna, sometimes it's more about your persistence and skill as an operator that yields results. 

So don't despair, even when you feel that you may not have the equipment required to snag those rare ones, you should be motivated by my experience and recognise that it really isn't all about the equipment. It is often very much about the operator. 

Good DX all and 73! 

Radio:  Yaesu FT-950

Antenna:  Sloper

Power:  100w

Location:  Lichfield

Visualising propagation with PSKReporter and FT8

For the first time in a while I had a relatively free Sunday so I took advantage of this by jumping on HF and exploring the state of HF propagation on the higher frequency bands (10m through 20m) using my Xiegu G90 (running 10w output) into a  simple quarter-wave vertical antenna in the form of a telescopic whip. This is easily adapted for any of the 20/17/15/12/10m bands by changing the physical length of the antenna. 

After some hours of operating and having found a sweet-spot in the 15m band, I used the internal antenna tuner in the G90 to tune the antenna (which I had set to 15m resonance) on the 17m and 12m bands with good results.

Log extract showing contacts on 17/15 & 12m bands

I checked with the HF Propagation website https://hf.dxview.org/ to see what I might expect and I used PSKReporter spots to visualise the extent of my transmitted signal. It was evident on the waterfall for all bands (I was using the JTDX software) that there was a high degree of variability (fading) in received signal strengths from all areas but it was particularly interesting to see just how closely the PSKReporter spots for my transmitted signal aligned with the predicted propagation on the various bands. 

Best DX to the west was W7CT in the state of Utah at approximately 5000 miles, to the east I had a contacts with UF8C in Krasnoturinsk and R9MJ in Omsk, both in Asiatic Russia, at approximately 2300 and 2900 miles distant respectively. All three of these contacts were on the 15m band.

These are screenshots I took from PSKReporter showing spots of my transmitted signal:

PSKReporter 12m spots

PSKReporter 15m spots

PSKReporter 17m spots

PSKReporter 20m spots

I have omitted 10m spots as I only made a single contact on that band and quickly moved onto the other bands.