wythall radio club

Wythall Radio Club’s Christmas Contest is approaching fast!!  If you only have a basic 2 meter antenna or just a handheld, or you want to get out portable, here’s an easy-to-build 2 meter antenna to boost your signal – from Neil G1TZC. 

There is a link to a pdf version at the end.

Many years ago I read an article somewhere about the Slim Jim portable antenna.  It might have been in Practical Wireless, but was a very long time ago.

Thanks to the late Fred Judd (G2BCX) we have this great little antenna available to us.

I decided that now there is an antenna analyser in the workshop (see previuous post on the nanoVNA), it was time to revisit this old friend.  After a bit of digging around the internet, various measurements were found and duly scribbled on a sheet of A4 paper.

From my memories of the one that I built many years ago was made from choc-blok (electrical connector – 15A) and coat hangers.

Initial sketch

We had also better think about some sort of base as well, as this version will be a table top version.

Ingredients

4 wire coat hangers (10 for £1 from Poundland last time I looked)

3 choc blok electrical connectors (15A)

1 length 50ohm coax with suitable connector for your radio

1 bamboo kebab skewer (yes really)

Material to make a base and fixing screws.

Tools

Wire cutters

Pliers

Craft knife

Terminal screwdriver (small flathead)

Tape measure

Soldering iron (optional)

How we make it

Let’s start with the good bit.  Let me begin by apologising for the quality of photographs – they were done on the fly without a tripod or lighting and on a phone.

Take the choc blok.  Cut this so that there are three terminals per strip.  The ones used here were 6 way 15A, but you may be using something different.

Complete and cut connector block

Cut the hook section off the four wire coat hangers and straighten.  Remember if there is any coating this either needs removing or scraping to bare metal for joining areas.

You should now have four lengths of wire.  To absolutely maximise the available metal cut off two of the hooks from the twisted section and straighten.  These will make the two ends of the antenna.  Exact measurements for these can’t be given because your choc blok will vary in size.

Fold short lengths of wire with a pair of pliers

Loosen the screws and insert the wire as shown above.  Cutting these slightly long allows you to change the length of the antenna during testing.  Always handy to have a little bit of give, just in case.

Now take two of the long lengths of wire and cut them to 930mmin length.  In a perfect world these will slot through the choc block a bit like a trombone.  Take another two three way connectors and remove the metal terminal from both.  Do not throw these connectors or screws away as we will use them later.

Slide one of the three way connectors about half way along the two lengths of wire and tighten the screws.  This is simply used as a spacer.  Now use the other connector at the open end of the two wires and tighten slightly.  Again, we are going to leave the option to trombone the metal a little if needed.

Take one of the remaining lengths of straight wire and cut it to 580mm.

Now cut the last length of wire to a length of 497mm (500mm will be close enough).

Find the other end section that was made earlier and insert the two wires to make an unbalanced U shape.

More hunting.  Find the two metal inserts that you set aside earlier.  Here we have one of two choices.  If you don’t have a soldering iron to hand then simply slide one of the metal inserts on to each of the legs of the unbalanced U.

If you have a soldering iron, strip the end of the coax cable ready for soldering.

Solder the inserts as shown.  Note one screw hole on each is uncovered.

Once the ends are soldered and cooled slip them on to the unbalanced U section.  The inner is connected to the longer leg and the braid to the shorter side.  Pinch tighten these close to the base of the U.  This will allow you to adjust the feed point.  In the workshop this was set at about 50mm to start.

Now slide a 3 way as a spacer on the unbalanced U section and tighten.  Using the final 3 way slide it in to place so that the short section is just fed through the connector.  Tighten this connector on both sides.

Connect the long side to the original U section and tighten.  In the workshop version the kebab skewer was used in the middle of two of the connectors so that it strengthens the gap section.

Effectively, the antenna is now complete and ready for use.  You could now tie a piece of string to the top and hang it somewhere (or tie spare bit of bent metal to the end and hang it over something).

Alternatively, the antenna can be bent through 90 degrees to make a table top version.  Let’s come back to that later.

Testing

Connect the antenna to your analyser – BUT DON’T  DON’T WORRY IF YOU DON’T HAVE ONE!

Testing can also be done by connnecting your 2 meter transceiver, low power setting, with your VSWR meter inline.

(OR if you only have a handheld, and no VSWR meter, then try listening on the 2 meter band.  If you can hear signals (especially if they are stronger than on a rubber duck antenna), chances are it will work fine.)   

Adjust the feed point as required to give the lowest reading you can.  Once you have reached the lowest point you can also adjust the overall length of the antenna from the various connectors.  This may increase or decrease the VSWR readings.  This is a bit experimental but that’s what the hobby is about.  The analyser plot below gives 1.5 or better right across the band.

The antenna should also work on 70cms – two for the price of one!

Analyser plot for the coat hanger slim jim

Optional Base

If the option of base is required here is an option that was put together in the workshop.  A length of 30mm wide pine was left over from lining the workshop roof so this was used for my base.

Foldable wooden base                                       Close up of skewer

Cut the base slightly longer than the bent section of antenna.  Glue two 30mm square blocks on the underside, one at each end.  Measure another length to be fitted in the gap in the underside.  Make this section 20mm shorter than the gap to allow for rotation to make a foot.  Place this strip in the middle of the gap and screw so that strip can be rotated.  You might want to drill a pilot hole to allow free turning.  If you use a long enough skewer you can use it to stabilise the upright.  Drill a hole small enough for a tight fit and push the skewer in to place.

I hope these instructions worked for you and you enjoyed it as a little project.

You can print off these instructions as a pdf by clicking here.

Neil – G1TZC

Neil, G1TZC, a Wythall Radio Club member, writes about his experience with a little Vector Network Analyser….

My local club runs monthly activities and this month there are activities on 80m to 30m and 20m to 10m.

As good as the 1/2 sized G5RV is it just doesn’t cover enough bands for this.

Recently I purchased a four inch screen version of the NanoVNA. I decided to pay a little more for a premium version.

I hadn’t realised when I made the purchase that part of the extra money went on the fact it has a much better antenna connector – the N type connector – mounted to the metal case.

My main advice is read the menu flow chart and take the time to download the online manual. The windows software is the right side of basic.

This has given a great chance to make a couple of antennas for the 12m and 30m. Using the analyser makes the whole process so easy.  You can see some of the screen shots below.

I shall be purchasing some more pvc covered wire to add extra bands. I think this will become my portable “go to” antenna for holiday operating.

It has also allowed me to check my 3 element 2/70 beam and the two colinears. I’ve even found that one of the 2/70 colinears works ok on 23cm.

If you have a little bit of spare cash and you want a handy test tool this is great. It allows you to check that antenna from the end of the coax.

Check out Neil’s qrz.com (G1TZC) page for more of his blogs.

Cayman, Puerto Rico, Madeira, Cyprus, and Malta were among the many islands contacted by Wythall Radio Club members in our November DX Challenge.

KP2M in the US Virgin Islands was a big signal into Wythall on 40 meters.  This station is the home of the Radio Reef DXers group. 

We also contacted several stations on the Aland Islands located between Sweden and Norway including OHoR and OHoZ.

And back in the Caribbean, contact was made with radio amateur Daniel, ZF2MJ, on Cayman Island.

Congratulations to Chris G0EYO and Neil G1TZC for topping the total DXCC and unique DXCC tables. Neil also just pipped Chris in the 40 meter tables.

On 80 and 160 meters, there was a close contest between the Chris’s G0EYO and G3YHF, with each taking honours on one band.

You can find a list of countries contacted here

We are continuing the 160 meter tables through December, January and February to see what DX members can work during the 4 winter months. 

For December and January, there will be two tables – one for the low bands (80,40 and 30 meters) and one for the high bands (20, 17, 15, 12 and 10 meters).  Each country will count once in each table regardless of the band or mode used.

Afghanistan (T6AA – see right), Madagascar (5R8AL ) and Trinidad were amongst the countries contacted by Wythall Radio Club members in their October DX Challenge.

The aim was to have two-way contacts with other radio amateurs in as many different countries as possible on the 20 and 40 meter short wave bands.

With 85 countries worked on 20 meters and 76 on 40 meters, Club members had lots of fun talking to people in other parts of the world.  They used digital, voice and Morse Code transmisions at all times of the day and night.

Here’s a list of countries we contacted.

And below you can see the way the contacts built up…  John 2E0XET (photo left) contacted the most countries, although he was using low power (50 watts or less from his KX3 and small power amplifier) to a simple wire antenna (a doublet) and Morse Code only.  Nice one, John!

Finally, the overall result….

November’s Challenge is on 160, 80 and 40 meters.

Wythall Radio Club members have been active contacting Scout groups around the world during JOTA/JOTI (Jamboree on the Air/Internet) 2020.

Les 2E0LRV spoke to Scouts from 2 JOTA stations last week end. 

“On Saturday I spoke to several groups of Scouts in Lillehammer, Norway. Their call was LA2L and was being run by Anders Forgen LA6UIA.

On Sunday I spoke to the Scouts from Crystal Lake Illinois, USA, who were using the call K9AT belonging to David J Holmgren, who sent this link about the event. 

Both Anders and David have passed on thanks from the Scouts.”

Les made both contacts through Hub Net using a Yeasu FT 8800 feeding a small colinear and back in to an All Star node connected to the wonderweb.

Both scout groups were trying various modes to make contacts and the feedback was that the contacts made using Allstar/Hubnet were by far the most popular and rewarding for the Scouts.

Meantime Tim M6OTN worked EA2KV in Spain on 40meters, leaving another happy group of Scouts!

This continues Wythall Radio Club’s support for Brownies, Beavers, Guides and Scouts – see our earlier posts, for example here.

Shields have now been awarded to Wythall Radio Club members for their achievements in the Easter Contest and Morse May, delayed due to the pandemic.

Over 40 members participated in the Club’s annual Easter Contest, and highpoints were QSOs with some of our more distant members in Scotland, Torquay and Derby. 

In the 2m/70cm FM section, the winner was Kev 2E0NCO (photo left), who was awarded the Colin Baker G6ZDQ Easter Contest VHF/UHF Shield, in memory of our former Club member.  Over the 5 days of the contest he achieved 124 QSOs with 37 different Club members  giving a total score of 3071 points!

There was very close competition for the top places in the all bands/all modes section.  David G7IBO came first (photo right) with 124 QSOs with 43 Club members over the five days, and a total score of 3655 points. 

He was awarded the David Dawkes G0ICJ Easter Contest all bands/all modes Shield, in memory of our former Club member.

Stuart M0SRZ (photo left) is the 2020 recipient of the Lew Williams Shield.  This annual award recognises a member’s progress with CW (Morse Code), and is in memory of Wythall Radio Club’s former CW tutor and President. 

The shields are shown in the order given above.

The RSGB has just launched today a series of videos to help the thousands of people who have taken their Foundation exam via remote invigilation whilst the Covid restrictions have prevented the practical assessments taking place.

The full 30-minute video highlights six practical tasks and each segment stands alone rather than being part of a single ‘story’ through the video. As well as this whole video we have published the different segments as separate short videos to make it easier to go back to just one or two parts again.

As the National Society, RSGB “wanted to create a video resource that people could use and return to whenever they needed some support.

We know that many clubs and individual radio amateurs have created online training courses and have been helping new licensees with these skills too and we’re really grateful for all the support being given by the amateur radio community.

With the launch of these videos we now want to add to the resources that new licensees have available to them.”

If you want to find the page quickly or share a link, this short url will be the easiest way: www.rsgb.org/foundation-practicals

Find out more about Wythall Club’s training courses on the ‘Training’ tab on our web site and for latest info click here

Yes, Wythall Radio Club members contacted exactly 100 different countries in their September DX Challenge!

Highlights included contacts with Western Sahara, the Falkland Islands and tiny Sant Marten island in the Caribbean.

The ‘ton up’ was reached using digital mode FT8 on the 40, 20 and 10 meter bands.  Not bad for this stage in the sunspot cycle and in late summer.

Lee G0MTN contacted 76 unique counties (each country counting only once across the three bands) while Ian M0LQY contacted 136 overall (the total of countries worked on each of the three bands).   

Lee and Ian shared the top 3 spots with Chris G0EYO.

As expected most contacts were on 40 and 20, although several countries were reached on 10 meters.

For a full list of countries worked, click here.

There was quite a race to the finish……

There are lots of counties to work on 30, 17 and 12 meters – as the results of the August DX Challenge at Wythall Radio Club show.

Mali (TZ4AM – QSL card left), the Falkland Islands and Trinidad and Tobago were amongst the more exotic countries reached by Club members.  For a full list, click here.

Tim M6OTN contacted 95 unique counties (each country counting only once across the three bands) and 152 countries overall (the total of the countries worked on each of the bands).   Chris G0EYO had 71 uniques and Neil M0LUH was close behind at 66. 

These three station were all using FT8, a digital mode of communication, and modest power with simple wire antennas.

This graphic shows how Club members’ unique countries increased over the month… 

FT8 is well suited to poor propogation conditions – which may be why the CW-only stations of Chris G3YHF and John 2E0XET were not as successful. 

However it is rumoured that some FT8 ops monitored the bands while they were doing other things – which is harder for CW ops to do!

The September DX Challenge is a FT8/FT4-only event on 40, 20 and 10 meters.  

Good luck and we hope for some excellent DX results!

STOP PRESS – THE INTERMEDIATE COURSE IS NOW FULL.  FOUNDATION COURSE STILL AVAILABLE.

Wythall Radio Club will be running ONE online courses in September.

The 8 week Foundation course starts on the 13^th September .

The examinations for both these courses will be done under the RSGB’s new remotely invigilated on-line examination scheme in the candidate’s own home.

Practical Assessments for the Foundation course have been suspended until such time as the COVID lockdown makes it safe for them to be re-introduced and the Practical Assessments for the Intermediate have been taken out of the syllabus altogether.

There is no charge for doing these courses and we do provide individual tuition via quizzes etc.  Please note that there are specific IT requirements which have to be met for the online examinations.

If anyone is interested in doing these courses with us please contact Chris G0EYO g0eyo@blueyonder.co.uk  ASAP.