wythall radio club

Don’t let a small garden stop you from getting on HF – including 160M! – reports Wythall Radio Club member Chris G0EYO.

End Fed (or long wire) antennas are the most simple antennas an amateur can make for the HF bands. However their simplicity does come with serious compromises when used as a multi-band antenna.

The physical length as measured in wavelengths of the transmitting frequency can result in very high or very low complex impedances at the fed end of the wire, so they need a very good antenna matching unit (AMU) to enable a good match to the transceiver and to deal with the high voltages or current that may exist,

The high currents or voltages at the end of the wire can also result in serious RFI problems for the amateur which are hard to control. This is because a quarter-wavelength in from the far end of an end fed antenna, the current is at maximum and the voltage is at minimum. At a half-wavelength the reverse occurs and so on.

So for a given length of wire and depending upon the band being used a wide range of complex impedances and currents and voltages may appear at the transmitter end of the wire. This is sometimes more than the AMU can handle, both in terms of impedance matching and voltages.

The end fed wire antenna produces quite complex radiation multi-lobe patterns unlike the simple “figure of eight” radiation pattern produced by a dipole. With multi-lobes come deep nulls in certain directions (diagram thanks to VK6YSF).

They also need a counterpoise or earth return to work well and avoid RF getting back into the shack. Ideally these should be about a quarter-wavelength long for each band the antenna is required to be used on.

We can avoid some of these issues if we can avoid wire lengths which are multiples of a quarter-wavelength of the bands being used.

So how long should our end fed wire be? A great deal of work has been done by others on the ideal wire length which avoids very large end impedances for the bands of interest and these can be found courtesy of Google.

My garden allowed an end fed wire length of approximately 25m to be accommodated in an inverted “L” format between a 10ft pole mounted on the side of the garage and a 20ft pole mounted at the bottom of the garden.

Alan Chester G3CCB in his book “ HF Antennas for Everyone” (RSGB) came up with a useful graphic which showed “practical” lengths for end fed wires. This allows you to pick a length and see which bands are will give you a matchable end impedance.

I wanted to work on all bands from 160m to 10m but ideally 80m, 40, 20m 15m and 10m. Alan’s calculations showed that a wire length of 18.5m would give an workable end impedance on 80m, 30m, 20m, 17m, 15m and 10m with possibly a little more troublesome end impedance on 160m, 40m, and 12m.

To avoid bringing high voltages and currents into the shack the AMU should be mounted outside and the signal fed into the shack via 50 ohms coax. Fortunately I had an SGC 230 Auto AMU that I had installed at my previous house in Hollywood.

The SGC 230 AMU is designed to operate with wire antennas and is configured as an “L” or “Pi” type network controlled by a microprocessor. The initial tuning takes several seconds to determine the transmit frequency and then select the necessary coils and capacitance to match the complex impedance of end fed wire to 50 ohms. These settings are stored in a non-volatile memory so the subsequent retuning of the same antenna on the same frequency only takes a fraction of a second.

The tuner has a ceramic insulated antenna terminal which looks as if it would tolerate quite a few volts, and a threaded nut for a earth counterpoise. It has a flying lead from the AMU with a 50 ohm coax and PL259 connector for the transceiver together with a 5 core cable for +12V DC, earth and “Lock Tune” control line and “Remote Tuner” indicator line.

On my installation I have a small plastic box next to the AMU which is a through line for the coax cable and a terminal block for the DC and control lines.  A 25m length of RG213 goes from the interconnecting box back to the shack in a bedroom at the front of the bungalow. Similarly a CAT5 cable is used to feed the DC and control lines back to a remote indicator and switch box at the operating position. This tells me when the SG230 has achieved a satisfactory match and locked on (and which can be confirmed by the SWR meter).

The SGC230 AMU is in a weather proof plastic box and is mounted under the eaves of my garage. A very short earth counterpoise is connected to the AMU earth terminal using copper braid and fixed to a 1 m earth rod driven into the ground. Overall the earth counterpoise is about 5m long and should probably be longer or with multiple earth rods. Chris G3YHF has suggested I do this modification to see if the efficiency improves. The antenna wire itself is Kevlar strengthened wire which is very strong but also very thin.

The pictures show the installation. I should say at this point that the inspiration to put in this antenna came entirely from Roger M0GWM who in 2019 said it was about time I put up some antennas having lived here for 3 years. Together we came up with the idea of using a long wire. Roger also did all of the installation work including running the coax and control cables around the bungalow just under the eaves.

Not long after the installation was completed, and always being a data mode fan, I got Ian M0LQY to set up FT8 on my computer and transceiver which is controlled by an old version of Ham Radio Deluxe. I limit the power to 30W (effectively carrier power – and probably equivalent to 100W PEP for SSB) and have been very pleased with the results.

Bands 160m, 40m, 20m, 17m 15m and 10m are rock solid. 30m suffers from RFI which upsets the wired mouse on the main PC in the shack and 30m seems to be constantly trying to find a good match. SWR’s achieved on these bands are between 1.15:1 and 1.35:1 which I am very happy with.

Strangely enough I never tried top band on any mode  until Chris G3YHF encouraged me to do so on FT8. I found it fun and challenging so made it my Wythall Radio Club DXCC challenge for 2020 (55 countries on 160M at time of writing). Chris has a similar set up with slightly longer wire length and bigger earth counterpoise. Analysis of PSK Reporter reports shows he just has the edge on me when it comes to performance, so don’t let a small garden stop you working 160M – 10M!

The VGC-VR-N7500 VHF/UHF FM Transceiver is the new kid on the block.

I was asked for help from a neighbour who had bought this and could not get satisfactory operation via Bluetooth to his iphone. Mindful of social distancing, he left the package on our doorstep for me to retrieve!

Unpacking it revealed the transceiver itself, heavier than expected and very solidly built, measuring 6” wide by 51/2 deep max (including the external mounted fan), a decent looking wired fist mic, mounting bracket, power lead (12v to 13.8v) and a PTT button to attach to gear lever/handlebars etc. and a Bluetooth fist mic. It seems some of the latter are available as cost extras but were included.

Being mindful that it was borrowed I did not wish to programme it beyond basic simplex or repeater use, nor set up the APRS or network capability.

On the bench, it was a matter of moments to connect the antenna (SO239),the fist mic via the now almost universal network cable type connection and the power. The rig was fused on both +ve and negative leads.

Downloading the Android app via Google Play Store and installing it took a few moments.

Enabling the app and Bluetooth on a Samsung Android phone (other makes are available), the rig and phone paired and the application started showing my GPS location.

Swiping the page brought up the programming screen and it took just a few moments to put in both 145.225 and GB3WL together with split and CTCSS as appropriate. No messing with usb leads, downloading drivers, finding a suitable programming app (or buying one) and reading/writing to the radio, this is where this radio shines. So intuitive, so easy and you can be up and running in moments. If going mobile (this in truth is the market sector targeted) the unit can sit in the boot and just operate via the Bluetooth speaker mic or indeed the Android phone.

On FM, it is rated at 50watts VHF and 40 watts UHF and those power levels were achieved feeding my “white stick”

Google is your friend the full specs and videos are easily found.

Works really well and although the price is around £190,this being twice the cost of say a Anytone AT778UV, its added capabilities may tempt folk.

Being SDR it is firmware upgradeable (by Bluetooth) which may well bring in more features and/or bug fixes as the product matures.

A 30 page manual is available https://www.moonraker.eu/downloads/dl/file/id/309/product/9250/vr_n7500_manual_v3_1.pdf

The Manufacturers website has more detail at http://www.vgc.net.cn/product/54-en.html

Please excuse the extraneous “QRM” on my desk- the unit to the left behind the rig is my MMDVM running YSF to my Yaesu FT2D.

This unit was on very short term evaluation so the photos were taken in haste!

Our Club newsletter archive hosts hundreds of Members’ articles covering all aspects of Amateur Radio.

Take a look using the link on our website and click here for an up-to-date index of Newsletter articles

73

Ian M0IDR

It’s May! And Morse Code appreciation month at Wythall Radio Club.

Everyone knows some Morse Code:  ‘ …  – – –  … ‘ = SOS!

At Wythall Radio Club during May we celebrate the skill of communicating by Morse Code in honour of Lew Williams, who was an expert at Morse and former Club President.

So Club members will be having fun by making contacts with other amateur radio operators using their Morse keys – which come in all shapes and sizes!

Many are ‘side-swiper’ keys, in which one paddle send dots and the other sends dashes.

Side-swipers are often used instead of the traditional ‘pump’ key, with its up and down action, because they reduce the amount of wrist action and operator tiredness.

However, pump keys are much better for learning Morse and for slower contacts. 

Here’s a short explanation for younger readers of how Morse Code was invented (you can skip the advert at start!).   

Ian M0IDR – a Wythall Radio Club member – reports on his build of this small low power transceiver.  This is the first in a series of reviews. His home is in a former orchard area, hence the title of these posts!

The QCX is a 5watt CW only transceiver with a very compact footprint which is available ready built or in kit form. Unfortunately the rather good aluminium case was discontinued in January 2019 and my purchase was a kit with case just as QRP Labs announced the change. The case can be bought elsewhere and details are on the QRP Labs website.

The kit and case shipped from America without any Customs charges, although it took some 5 weeks to arrive. Very well packed indeed with all components bagged by type.

Not for the faint hearted, I suggest, as assembly involved a fair bit of tricky intricate coil winding.

The assembly instructions are downloaded from the website and run to over 140 pages of very clear detailed instruction.

Having a fine tipped temperature controlled soldering iron made for perfect soldering first time around as removal of any multilegged component would prove very difficult. A desoldering station was on standby just in case.

The multi-winding coil was by far the most difficult to assemble but inductance measurements proved each winding before fixing into position (photo left).

Assembly proceeded in strict order of instruction and the completed board was mounted within the case (photo right).

Assembly complete – the unit on test (photo below)!

Since building this, I have purchased a second user GPS module – QLG1 – which can be added to effectively use the rig as a WSPR beacon.

This module is only available in kit form and interfaces to the QCX via a 4 core umbilical cord.

For the moment, I am pleased that the QCX assembly was trouble free and look forward to interfacing to the GPS module when time permits.

Upgrade your Foundation licence through study at home with Wythall Radio Club.

Our new FREE on-line Intermediate level training course under the new syllabus starts this Spring.

The course will run over 10 weeks, from 2^nd March until 11^th May, with two lessons per week.  The examination will be around 23^rd May.

You now need to register your interest.

You study this course at home in your own time from lessons you download from the internet, as you did at Foundation level.

In addition there will be one practical assessment session, usually on a Saturday, where you will learn soldering, digital measuring and other skills. This will require you to be available for ONE Saturday in April, but there will be a choice of dates.

The course is FREE but there will be an exam fee of £32.50, an exam room hire fee of £6 and a project kit and materials fee for the practicals of £12.  You will not need to pay this until the course starts.

You will also need to purchase the RSGB Intermediate Licence Manual from them at £9 plus postage – or visit the RSGB Bookstall at Wythall Hamfest on the morning of Sunday 15th March. 

IF YOU WISH TO SIGN UP FOR THIS COURSE YOU MUST CONFIRM YOUR INTEREST AS SOON AS POSSIBLE TO OUR Training Coordinator Chris G0EYO  via G0EYO@blueyonder.co.uk  

PLACES WILL BE LIMITED AND WE WILL WORK ON A FIRST COME FIRST SERVE BASIS

Radio signals from Wythall Radio Club members reached remote parts of the world – including New Zealand, Sri Lanka, Mali, Seychelles, Guinea-Bissau, British Virgin Island and South Korea.  

The Club’s annual DX Table involves members logging their two-way radio contacts with other countries.

In 2019, Tim MoURX was top of the Table with 165 countries. He was closely followed by Jamie M0SDV and Lee G0MTN with 145 and 142 respectively.  These are all in the Full licence category where operators are allowed to use higher power.

John M6KET won the Foundation licence category with 78 countries contacted, using QRP (low power) – no more than 10 watts output and a simple wire antenna. 

During the year he passed the exams for the Intermediate licence, and also won that category with 63 countries – but continued to use low power and a wire antenna.   He operated 100% CW (Morse Code) rather than using voice transmissions.

It shows what can be achieved with simple equipment despite the poor radio conditions.

Special awards were made to several Wythall members for achievements during the year.

Tim M6OTN (photo) contacted A73A in Qatar – a small country in the Arabian peninsular – with his basic antenna, a short mobile whip.  He won the ‘piece of wet string’ award – so named as wet string can be used as a very basic antenna to transmit radio waves!

Chris G0EYO won the ‘midnight oil’ award for contacting 50 countries on Top Band (160 meters), again using low power and a simple wire antenna.  The award is called ‘midnight oil’ because Top Band contacts can normally only be made during nightime, due to propogation conditions.

And Neil M0LUH won the ‘pipped at the post’ award for achieving 99 countries by 31 December (the closing date for the DX Table competition) – but then contacting what would have been his 100th the next day!

The competition is also open to short-wave listeners who don’t have a transmitting licence. 

If you don’t have an amateur radio licence, but would like to gain one, then come along to our Club one Tuesday evening or see the ‘Training’ section of the web site.  A warm welcome awaits you.

Twenty-five scouts from 1st Tidbury Green enjoyed an evening of communications activities hosted by Wythall Radio Club.  The scout group is a neighbour of the radio club, both located in Wythall Park.

Scouts took part in four activities – sending names and messages by Morse code, using licence-free handhelds to pass messages using the phonetic alphabet, learning about WebSDR and satellites carrying amateur radio, and passing greetings messages over the air to other radio amateurs.

Although radio conditions were not good during the evening, we did speak to stations in Germany, France and Scotland using short-wave radio on the 80 meter band.  We also used vhf radio on the 2 meter band, and had contacts with stations around Bimingham, Redditch and Cheltenham.

Some of the scouts used the phonetic alphabet they had learnt earlier in the evening to spell out their names when talking on the air.

The evening’s activities involved 5 Wythall Radio Club members plus another member on the air.  It forms part of our outreach activities for youth groups, and we welcome enquiries from similar groups in the area.

Wythall Radio Club put on a team effort for the Beavers of 1st Tidbury Green Scout Group.  As a result, 30 Beavers – aged 6 – 8 years – achieved their Communicator Badge and a Certificate of Achievement from the Radio Club.

We had 4 members working with the Beavers on a range of activities – learning how to send their names by Morse code (see photo), using licence-free walkie-talkies to pass secret messages using the phonetic alphabet, and passing a greetings message to 3 additional Club members on-air.  This used the Club’s 70cm repeater GB3WL.

As December is ‘Youngsters-on-the-Air‘ (YOTA) month, we used the special callsign GB19YOTA with the Beavers.  And a coordinator of this international YOTA month is Jamie, M0SDV, one of our teenage Club members.

It was a hectic hour but the Beavers threw themselves in to the activities and went away happy if exhausted.

Get on the air with an amateur radio licence by following Wythall Radio Club’s new free, on-line Foundation course starting in November.

The specially designed course provides you with an exciting introduction to the hobby.  After passing the straight-forward multiple choice exam, you can obtain your own callsign for use when communicating with other radio amateur operators worldwide.

This course is planned to start on the 25^th November and complete by 10^th of January with a one week Xmas break.  We will be using the new RSGB (Radio Society of Great Britain) Syllabus introduced in Sept 2019. 

Wythall Radio Club’s tutors have many years experience and achieve a very high pass rate for their students.  

Students can study in their own time following this specially designed on-line course, with support via posts from the tutor.  You also need to have the necessary free time to do the course.If you need special assistance because of any disabilities then please let Chris, the Training Coordinator, know.  You also need to have the necessary free time to do the course.

The course is based around the free-to-use virtual learning experience (VLE) software named EDMODO.  This has gained world-wide acceptance as a safe and easy way for tutors to connect with their students at home via the internet.

You sign up for the course free of charge and you get notifications via e-mail that the course material and quizzes are available for you to download.  This takes place over a 7 week period with two lessons per week in the comfort of your own home and at a time of your own choosing.

We will set a date for the practical assessments (usually done as a group on a Saturday) and the exam when we know how many people will be on the course. These should be done in January or early February.

Although the online course is free of charge, there is an examination fee of £27.50 plus £6 room hire cost to do the practical assessments and examination at Wythall Radio Club.

You will also need to purchase course book “The Foundation Licence Manual for Radio Amateurs” by Alan Betts G0HIQ from the RSGB.

If you are interested in joining this on-line course then please contact our Training Coordinator Chris G0EYO  via g0eyo@blueyonder.co.uk

Six members of the 127th Birmingham Brownie Troop made a very successful visit to Wythall Radio Club’s shack.  The girls are working towards their communication badge.  They took full advantage of the activities offered by the event’s host – Lee G0MTN, seen in the picture with an enthusiastic visitor!

After a quick introduction to radio communication – illustrated with some pictures – they had time to try sending Morse code messages and look at QSL cards and match them up to countries on a map (see photo).

They then sent a coded message using the phonetic alphabet on PMR446 handheld radios.  They also watched Lee conduct a contact on the 40 meter amateur radio band with an Italian operator. 

Having gained some knowledge and experience, the evening concluded with the Brownies sending greetings messages by VHF radio to Jan M3YXM, another Club member operating from her home. 

Photos are used with permission.