RSGB 70MHz UKAC 16th February 2017

This is another first for me! I have never been on 70MHz before since I got my licence in the 80s. So this one was going to be interesting! I can see from the previous entries that activity levels are lower than most of the other bands but I think it is on the up and the Hereford ARS does have a few members active on this band.

I don’t actually own any 70MHz equipment myself at all but Matt G8XYJ has loaned me both a transverter (actually both of his) and his 4 element DK7ZB portable yagi. It was small enough to take on the roof bars which is a nice change and helps speed up the rush of building the station and tearing it down to get home when you are operating out in the the sticks portable.

I found it a bit harder work than usual but still better activity than we had on 432MHz in the 80s! I came in 4th in my low power section which I am pretty pleased with. Top of my agenda though was a new longer beam as a few stations I could hear just couldn’t hear me but I am sure a much longer yagi will make a good difference.

My QSO map:
70MHz UKAC 2017-02-16 map
Claimed scores (top 10):
Claimed scores 70MHz UKAC Feb 2017
Final scores (top 10):
Final scores 70MHz UKAC Feb 2017
Hereford ARS member scores:
HARS members results 70MHz UKAC Feb 2017
70MHz Local club standings so far:
Local club standings 70MHz UKAC Feb 2017
Full result list (PDF)

RSGB 50MHz UKAC 9th February 2017

Second time out with the long yagi for 50MHz. This time I have the side guys finished for it. These not only help protect the thin 20mm boom from the wind but also help me assemble it. There is considerable sag on the boom and as I assemble the boom to the mast the forces on the clamping of the boom supports to overcome are quite massive. Imagine holding a long pole out horizontally by only the amount you can get in your hand at the very end. But once the side guys are fitted and supporting the boom and boom supports all is great and easy to assemble:
50MHz 6 element yagi side guys
So far the side guys have not been properly tested and I hope it stays that way! That said I have good confidence the system should survive in any wind I am still able to erect it in by myself.

My QSO map:
50MHz UKAC 2017-02-09 map
Claimed scores (top 10):
Claimed scores 50MHz UKAC Feb 2017
Final scores (top 10):
Final scores 50MHz UKAC Feb 2017
Full result list (PDF)

Hereford ARS member scores:
Hereford ARS 50MHz Member scores
50MHz Local club standings so far:
RSGB 50MHz UKAC Local club standings Feb 2017
Full result list (PDF)

RSGB 144MHz UKAC 7th February 2017

Round two of the 144MHz UKAC series in 2017. This is the first year I have taken part from the start so I am intending to put a good effort in and hope I can continue to do well as I did in the end of 2016. Also now as part of a participating club team I feel it important to contribute as good a score as I can. This month we have the addition of Dave G4ASR adding his score as well as a few more of the club.

Anyway, business as usual and crack on. This is being written a month later as it has been a busy month for me with more bands and more jagi building, so memory of details is now faded. Activity was good for me which is essential as although I often do very well on QSO points based on basic points per km, the biased B2 bonus system makes it hard to stay ahead of those with those in good reach of the juicy 2000 point red squares. Anyway, soap box over all we can do is bash away and if I can get 3G signal try and find some mults on KST chat. recently I have had 3G access a few times and this contest may have been one of those. Even so I got the lowest bonus points in the top 3 places in my section.

My QSO map:
144MHz UKAC 2017-02-07 map
Claimed scores (top 10):
Claimed scores 144MHz UKAC Feb 2017
Final scores (top 10):
Final scores 144MHz UKAC Feb 2017
Full result list (PDF)

Hereford ARS Members results:
HARS members results 144MHz UKAC Feb 2017
Hereford ARS standing in local club section:
Local club standings 144MHz UKAC Feb 2017

RSGB 144MHz UKAC 6th December 2016

This was my last contest session of 2016 on the back of two successive section wins. So the pressure was (put) on myself to try for a hat trick of section wins.

No changes to the actual transmitting station this time but some refinements to the overall station environment.

First up was a quickly deployable rain shield for the generator. I have the Honda EU20i suitcase genny:
Honda EU20i Generator
This is a great little genny that is electrically quiet on HF and at the low power I am running doesn’t change a beat between receive and transmit running on the economy mode. In that mode I reckon it should do 9 hours easy on one tank. However the AC outlets on this model are normal BS 1363 three-pin 13A sockets which are not very rain proof. So far I haven’t had this in the rain but I no doubt will so for my UKAC site I made a simple shelter to stop direct heavy rain (it was very low cloud for this contest and with flash the picture is not great!):
Generator shelterIt is a £1 tarp 1 square metre from Tesco with an eBay lightweight key ring size karabiner on two corners and two tent pegs on tent guys. Takes literally 20 seconds to deploy here as the genny is set up next to a chain link fence.

The other issue I addressed for this contest is in car lighting. I log on a Micro$oft Surface Pro 3 tablet with keyboard. I turn of the key lights to save battery, and even if I leave them on they go off after no use to save battery, so I like to have a light on to see the keyboard so I can spring into action when I get a call. This current car as well as having the first headrests that are a nightmare to get off (and needed mods to make that fast) the rear light will not stay on. It has some stupid timer on it so I am probably often heard on air slamming my car door as I have just opened it to get the lights on again. In these winter months it doesn’t help keep me warm. My daughter was throwing out her touch bedside lamp as the touch part doesn’t work any more and it is on permanently so it seemed a plan to recycle that for contesting. Sorted!

Anyway, the contest went well although a LOT of QRM from a couple of local as crow flies stations tonight, more than usual. Not as many QSOs as last time but some good spells of activity. But this was the first contest this year (and century!) where it was judged I had a perfect log!

My QSO map:
144 UKAC 2016-12-06 QSO map
Claimed scores (top 10):
Claimed scores 144MHz UKAC Dec 2016
Final scores (top 10):
Final scores 144MHz UKAC Dec 2016
Full result list (PDF)

UK and Europe VHF Contesting Maidenhead Locator Map

With the introduction of the B2 scoring system in 2017 I decided it was time to update my VHF contesting map that I use to help me aim the beam and find multipliers and bonus squares when out portable.

I have beam heading marked centred on my portable locations. They are close enough together at this scale to us just one point.
G1YBB B2 contest Locator map
I usually take an A4 print of this map with me to refer to but the PDF file is fairly high resolution and should be printable at least A3 size at decent quality. Here is a 100% view of the map to see the detail:
100% scale view of detail

You can download it if you wish but if you wanted one centred on your location you can always email me (my email is on the home page here). The annotations are all done in vector layers and can easily moved around to suit. Here is my PDF for a look but it’s probably only any use to David G4ASR and other portable stations in my area.

G1YBB B2 Contesting Locator Map of UK & Europe (15.4MB PDF)

However several people have asked for a copy of the map centred on their locator so one of these below may be of use for you. The centre point of the beam headings covers a couple of squares around the actual centre so one near yours. If not you can always email me.

G1YBB B2 Contesting Locator Map of UK & Europe from IO93EG

G1YBB B2 Contesting Locator Map of UK & Europe from IO90WX

G1YBB B2 Contesting Locator Map of UK & Europe from IO92FI

G1YBB B2 Contesting Locator Map of UK & Europe from IO92IR

G1YBB B2 Contesting Locator Map of UK & Europe from IO93KE

G1YBB B2 Contesting Locator Map of UK & Europe from IO90HX

G1YBB B2 Contesting Locator Map of UK & Europe from JO02KM

G1YBB B2 Contesting Locator Map of UK & Europe from IO82PC

G1YBB B2 Contesting Locator Map of UK & Europe from IO93TB

G1YBB B2 Contesting Locator Map of UK & Europe from IO93KH

G1YBB B2 Contesting Locator Map of UK & Europe from JO01JK

G1YBB B2 Contesting Locator Map of UK & Europe from IO70SS

G1YBB B2 Contesting Locator Map of UK & Europe from IO71LX

G1YBB B2 Contesting Locator Map of UK & Europe from IO82RJ

G1YBB B2 Contesting Locator Map of UK & Europe from IO83PN

G1YBB B2 Contesting Locator Map of UK & Europe from IO93MG

G1YBB B2 Contesting Locator Map of UK & Europe from IO93RF

G1YBB B2 Contesting Locator Map of UK & Europe from IO71VO

G1YBB B2 Contesting Locator Map of UK & Europe from IO83MR

G1YBB B2 Contesting Locator Map of UK & Europe from IO91QN

G1YBB B2 Contesting Locator Map of UK & Europe from IO91WP

G1YBB B2 Contesting Locator Map of UK & Europe from IO76XA

G1YBB B2 Contesting Locator Map of UK & Europe from IO70TQ

G1YBB B2 Contesting Locator Map of UK & Europe from IO85NS

G1YBB B2 Contesting Locator Map of UK & Europe from IO92PU

G1YBB B2 Contesting Locator Map of UK & Europe from IO82KR

G1YBB B2 Contesting Locator Map of UK & Europe from IO70UM

G1YBB B2 Contesting Locator Map of UK & Europe from IO86JV

G1YBB B2 Contesting Locator Map of UK & Europe from IO86GB

G1YBB B2 Contesting Locator Map of UK & Europe from JO02MA

G1YBB B2 Contesting Locator Map of UK & Europe from IO83VT

Portable 6 element 50MHz DK7ZB long yagi

Towards the end of 2016 the rules and days for the UKAC series of RSGB contests was changed. The 50MHz and 70MHz UKAC events were moved to the 2nd and 3rd Thursday of the month respectively. This opened up more opportunities for me as working a Tuesday night contest means rescheduling my Tuesday to a Wednesday and means my Wednesday is busy as heck and it’s at least Thursday before I can even look at the tablet to get the log updated. But a Thursday I am usually free so I can get on another band. As I have no 70MHz Tx capabilities I decided 50MHz was the way forward for me. I have an old home made 5 element yagi we used to use but I wanted a newer better performing yagi. I am getting awesome results with my 144MHz 9 element yagi I decided another DK7ZB sounded ideal.

I chose the 6 element 7.2m boom version as I plan to only use it car portable and it’s only 1m each end longer than the 144MHz yagi I’m using. Also it has a great SWR curve. All dimensions are available on Martin DK7ZB’s site:
6 ele DK7ZB yagi dimensions
This design only had figures for 12mm elements. That was OK as I can get 12mm pipe clips like I used in the 144MHz yagi. But it turns out buying 12.0mm tube in lengths greater than 2000mm in the UK is exceedingly difficult. It had been suggested to me to use 12.7mm tube as that would be easy to buy in the UK but would require recalculating the element lengths. Not only that it would prevent me from being able to use the fast fit pipe clip I wanted to use. After much searching and asking in various places I had to admit defeat and arrange with Attila at to ship (at some considerable expense) some 3000mm lengths of 12mm tube, along with several other antenna parts and also some 3000mm lengths of 10mm element tube.

For this yagi, unlike the 9 element for 144MHz, I had no plans to take it backpacking portable so I decided it only needed a 2 part boom. I was easily able to get 5000mm lengths of 20mm boom for this. 20mm is quite small sized boom for a yagi of this size but my element mounting plates are designed for 20mm boom only. I’ll be using truss supports and side supports if required to stop it flexing too much. The 5.1m long 2m yagi was nice and sturdy with its trusses in high winds on the top of the Black Mountains. Although it’s only 1 metre longer each end, it makes for a big boom!
7.2 metre long boom
Once the element positions were marked up the 5 parasitic element clips were fitted in the same manner as the 144MHz 9 element. On this yagi the driven is too big for the element clips so that will need a more conventional box:
element clips fitted to boom
For the feed box I decided to go for a beefed up version of that I did with the 144MHz 9 element. I chose an ABS box from Farnell as it is quite thick walled and with a decent lid should be pretty stiff and is also IP65 rated (before I start drilling it). In order to get a suitable height so the driven element 16mm sections could be on the same plane as the parasitic elements it came in quite large at 200 x 150 x 55mm but that is OK as the driven on this 50MHz is quite big:
Farnell 1526658 box
Here it is marked up for drilling. Marking needs to be spot on as this is what makes the driven element parallel with the parasitic elements in both planes so is crucial!
driven box marked for drilling
This is the centre point of the dipole box used for locating it on the boom in exact position:
dipole box centre locating hole
To enable stability and strength for the 3 metre driven element I am using some 19mm angle. The sighting hole above lines up with the centre of the scribed line:
dipole box supporting angle
To mount the two halves of the dipole I got my good friend Paul to 3D print some two part clamps in ABS to my design so the centreline height of the driven element above the boom matches the parasitic elements so all elements are in the same plane. Here are the clamps after drilling and fitting to the box with some 16mm tube to check alignment:
driven element clamps fitted
To fit the dipole box I drilled and tapped an M2 hole in the centre point of the boom on the scribed line as seen above and screwed the dipole box in place using the 2mm sighting hole. I then fitted the reflector and first director and ensured they were all parallel and drilled the box to fit the two angle pieces:
fitting dipole box to boom
When I bought the element materials from I also bought their dipole centre for 16mm tubing:
nuxcom 16mm dipole centre
Which is very chunky and strong. But the 16mm tubes fit inside the joiner and I couldn’t see how one would get a good secure contact to the elements. So I got another good friend Ed to turn up a piece that would fit inside the elements like the nuxcom one for 10mm elements does. Here is the mechanically finished dipole centre:
finished dipole centre
The eagle eyed may be wondering what the red things are in each end. Well as I am using jubilee clips to clamp the 16mm tubes down onto the 12mm main driven element parts, once they are removed for transport (this yagi is for portable use remember) the jubilee clips are free to fall off unless clamped down. So my I got some plugs 3D printed to clamp onto to retain the jubilee clips and also prevent any dirt ingress during transport and storage:
jubilee clip retainer plugs
Now the dipole needs the DK7ZB match. I’m using the same WF100 75ohm coax I used on my 144MHz DK7ZB, which is fairly low loss for its size, and is not too big or heavy. Its claimed velocity factor is 0.85 so I worked out the length as so:

300/50.150 = 5.982m full wavelength
5982/4 = 1495.5mm for quarter wave
1495.5 x 0.85 = 1271mm

As before I used a section of boom to tame the curling of the coax to allow accurate measurement and cutting of the lengths:
making the DK7ZB match
DK7ZB match one end
DK7ZB match other end
One end of the match fitted:
dipole wired to DK7ZB match
A picture of the process in operation in the ‘workshop’:
the G1YBB construction workshop
Other end of the DK7ZB match completed:
coax feed box
Apart from the bracing the antenna is pretty much complete except for the fact that the element mounting plates are not really man enough for 3 metre long 12mm elements. They were designed for the 144MHz yagi and only 1m long 10mm elements, which they are perfect for. With the larger elements this is how they were flexing with gentle persuasion:

A quick chat with Paul and he drew up a two part brace that he could 3D print me and soon they were in the post!They utilise the same holes already in the element plates and wrap underneath adding strength without interfering with the element clips at all. I used M4 nylon screws to add extra fixings without adding extra metal, the only metal nut and bolts holding the element clips on:
element plate brace fitted
After fitting the new bracing parts this is the flex with quite boisterous provocation:

Much better!

My next consideration is bracing. Long supports were made and fitted utilising the same fittings as on the 144MHz yagi. In fact as I write this I have started work on a 70MHz yagi. All three will fit on the same fittings on the portable mast, and the 70MHz yagi will re-use one of the 144MHz yagi braces and one of the braces for this yagi. The angle of the supports is quite narrow but they do support the boom and keep it straight. This yagi also will need side guys to protect it from the wind. I have several bottom sections of 4m fishing poles left over from HF antenna projects so I utilised two of those. Again Paul quickly produced some parts for me. Some ‘plugs’ to fit to the mast plate to mount the poles onto:
side guy pole fittings
And some stoppers to go in the end of the poles for the 3mm dacron cord, which is very strong and has very little stretch. The stoppers are a good interference fit:
side guy rope stoppers
side guy with rope fitted
Side guy poles fitted to the mast. These are a friction fit to the ‘stoppers’ and quickly assembled on site:
side guys poles fitted
The sides guys clip onto a plastic bushed (thanks Paul!) bolt on the boom supports with a single karabiner each end. Very quick to deploy:
side guys and supports fitted
Next step was to test it! This was done after work on the Wednesday before the first 50MHz UKAC in Jan 2017 the following day! It was reading 1:15 throughout the SSB portion of the band, which was slightly disappointing. There was no time to look into this as I needed to get back home (testing was done in a mountain’s car park) and pack for the next night’s contest!

On the night of the contest the in radio SWR reading was quite low so I was happy the radio was feeling OK about the match and used the new antenna for the first 50MHz contest I have done in 20 years. The yagi seemed to work pretty good and I even managed to beat G4CLA in the AR section of the RSGB 50MHz UKAC January 2017, which I was delighted with!

This is the only photo I have of the yagi on a mast so far, I’ve not seen it fitted in daylight!
first test of 50MHz 6 element DK7ZB

RSGB 144MHz UKAC 3rd January 2017

In this first UKAC of the new year many things have changed. Not my station or location but most notably changes to the rules. Causing much controversy a new B2 bonus scoring has been brought in to replace the M7 multiplier giving a heavy bias to Scottish squares. More than enough (and some!) has been said about it so I will not pursue it any further here. Instead of multipliers for squares like M7 we get a different bonus values for squares to this map:
RSGB B2 bonus scoring system

Anyway, my plan is to crack on and see how it goes and hope the VHFCC’s promise of a review comes to fruition, and sense!

One more major rule change is the splitting of the club categories from one overall category to a local and general. As all our members (bar one!) are covered by the local category it gives us a bit more of a fighting chance not being grouped in with groups recruiting from all over (and outside) the country.

The other big change for me this year is in terms of my club, Hereford ARS. One of our existing members Matt G8XYJ is now putting his efforts in UKAC in for HARS and we have two new members Tristan M0VXX and Craig M0BUL. All three are winning VHF contesters meaning HARS will get four times as many points a month in 144MHz. Not only that but the several other club members are also joining in to build up the scores! Amongst these are Stuart G3WRA, Bob G3IXZ, Richard G4FAD (on SSB not CW!!), Alan G7RHF, Nigel G4XTF, Derek G3WAG and Duncan M0OTG. This is great to see and I hope we can get even more members interested.

Anyway, the actual contest went well for me. Activity was very good and I managed to work 153 QSOs, which in 150 minutes of contest is the first time I have averaged over 60 per hour for an entire contest. I’ve done 80 or so an hour in a couple of hours of a 24 contest but this is the first overall average over one a minute! Well chuffed.

Even better after adjudication I still had 153 QSOs, my second perfect log in a row!

My QSO map:
144MHz UKAC 2017-01-03 map
Claimed scores (top 10):
Claimed scores 144MHz UKAC Jan 2017
Final scores (top 10):
Final scores 144MHz UKAC Jan 2017
Full result list (PDF)

Hereford ARS Members results:
HARS members results 144MHz UKAC Jan 2017
Hereford ARS standing in local club section:
Local club standings 144MHz UKAC Jan 2017


RSGB 50MHz UKAC 12th January 2017

For 2017 the RSGB VHFCC have moved the 50MHz (and 70MHz) UKAC events to a Thursday night. Whilst a lot of UKAC regulars are not happy about this it suits me much better than a Tuesday so I have made myself a 6 element DK7ZB yagi for the 50MHz series!

It was a rush to get it done in time as Xmas break slowed my building of the new yagi down but I managed to get it usably finished mechanically on Wednesday the 11th after work and then drove out to test it electrically, getting home by 10.30pm on Wednesday night. The match to 50ohms wasn’t as good as I would have liked at an SWR of 1.5:1 but I decided it was usable anyway so headed out on the Thursday after work.

This is a terrible phone picture of the yagi on the mast taken on the Wednesday test night. The yagi is actually longer than my normal size 6.1m scaffold pole mast:
first test of 50MHz 6 element DK7ZB
On the evening of the contest several heavy snow showers were forecast and then changed to some light ones. I decided to head up to my usual spot anyway. On arrival on site I was pleased to see no snow at all. However getting out of the car to start unloading the car I nearly slipped over. The single track dead end road apparently was covered in frozen rain! Undeterred I started to unload the car. Shortly after the snow started! This is how much had fallen in the short time it took me to fit the mast to the base and set the guys (which takes a few minutes):
snow starting to stick already
Boom supports set down for about a minute!
boom supports gathering snow
There was nothing for it really other than to carry on setting up and worry about getting down the hill after the contest.

This was my first time on 50MHz since the late 80s so it was a relatively first time for me. I found conditions weird. They seemed very poor but for the first hour I had a lot of activity. It was a lot harder work in the last 90 minutes though. I was surprised to have G4CLA call into me! Only two of the very controversial Red Scottish 2000 point bonus squares. It was pretty cold, the first time I have had to put on gloves whilst operating as I don’t run the car engine normally when operating.

The second the contest ended I switched off and started to pack away. The genny had collected a little snow despite being in its little shelter:
generator collecting snow
The snow on the mast base. This was actually on the sheltered side of the car:
mast base collecting snow
Just as I finished packing away it started blizzarding again so I was lucky to have a small window without snow to tear down in. I used the Passat Alltrack’s descent assist to get down the hill on the 2 inches of fresh snow. It worked really well and felt completely in control and secure.

I ended with 104 QSOs which seemed disappointing, but it turned out to be the highest QSO count and highest claimed score of the event which I was very pleased with. All the frantic work on the long yagi looked to have paid off! Not many portable stations out tonight though.

My QSO map:
50MHz UKAC 2016-01-12 map
Claimed scores (top 10):
Claimed scores 50MHz UKAC Jan 2017
Final scores (top 10):
Final scores 50MHz UKAC Jan 2017
Hereford ARS member scores:
Hereford ARS Member scores
50MHz Local club standings so far:
RSGB 50MHz UKAC Local club standings Jan 2017
Full result list (PDF)

End of year contesting roundup 2016

The first year of my return to Amateur Radio contesting (or Sport Radio as it is often known as these days) came to a close for me after the December 144MHz UKAC event.

Overall I have been delighted with the results I have had both as a single op and also the invaluable help and second pair of ears from Paul G1YFC.

My year started late in the season, partly because I was still building a new 144MHz yagi and partly because I did have a few failed starts.

My first attempt in the UKAC was in March. I decided to try operating from the Blorenge as it is a drive on site and I’d planned to set up in or next to the summit car park. That was scuppered by extreme wind and my finding the ground adjacent to the car park was just too rocky to take the guy pegs I would need to have a chance of keeping a free standing mast up in the strong winds. This is what happened to my yagi while still strapped to roof bars on the car:

Myself and Paul G1YFC next planned to give some points away in the RSGB March 144MHz contest and duly arrived on site and set about erecting one of my old DJ9BV yagis. When it came to attaching the coax feeder we discovered a small issue in the fact we had different coaxial connector types and no adapters! Fail.

Finally I did get on air successfully in the April 144MHz UKAC event, backpacking to a site I used to use in the 80s. I managed 3rd in the 10W low power section with 5W from the FT-817 so was pleased I could still do the business under contest conditions. Here is a brief clip from a later UKAC event that Paul took of me, notice the signal report I receive and the fact I am using an FT-817 barefoot (5W):

We were now away and managed to enter all the contests we could attend bar a failed attempt on a UKAC later in the year (wrong battery to power lead adapter, doh!). As the season went on I honed the UKAC station, adding a rotator, new generator to power the rotator (after first using an inverter) and stop needing to use the backpacking battery, and a drive on mast base and scaffold pole. All changes were primarily to make the UKAC station quicker to erect and tear down. The scaffold mast and drive on base making the most significant gain.

Here are the events entered over 2016 with the results and sections where applicable:
G1YBB 2016 results list
Very pleased with EIGHT 1st place results from 13 entries! Also of note is the 4th place result in the Open section of the 144MHz Low Power contest. That event is 6 hours long and up to 25W RF output and any antenna array. Our entry was the 3 hours of the 4th Backpackers event that co-incided with the 6 hour event, and we were using 2.5W and a single yagi ! We did have a fantastic location and good conditions, but still very pleased with that.

Final standings in the RSGB Backpackers series (which was the main goal at the start of the year, along with PW):
GW1YBB 2016 Backpackers results
Full results table of the 144MHz Practical Wireless QRP contest:
GW1YBB 2016 PW 144MHz QRP results
G1YBB station final section standings in RSGB 144MHz UKAC (top 20 from 193 entrants) 14th from entering 7 out of the 12 sessions:
G1YBB 2016 144MHz UKAC results
In the UKAC 144MHz section Hereford Amateur Radio Society managed to get 38th position from 105 clubs and groups, but bear in mind that is a one station entry (until some help in last two events) up against groups and clubs with dozens of team members. In 2017 we are hoping to do better!
Hereford ARS 2016 144MHz UKAC results

Updates to portable car table

I have been using a piece of ply for years as a car portable operating table in many cars and still do, described here:

After I made a post on the UK VHF Contest group on Facebook I got a reply from Dave G3WCB showing his cool car portable setup. I had already very recently thought of doing something similar but seeing his setup gave me an idea for a simple and quick update to my plank of wood.

I already locate it over the steering wheel for some security to stop it toppling over and trashing my radio gear but seeing Dave’s set up I realised I could secure the other end with two simple locating pegs and make it virtually idiot proof. Out with the 3D design and quickly knocked up a tapered peg to fit the headrest sockets. I included a recessed hex to take an M4 nyloc to save having to over tighten a bolt onto wood and split it:
3D modelled headrest peg
Shortly sent the file to my very generous friend Santa Paul who 3D printed me some and they were in the post!

A quick measure in the car and drilling and job done:
pegs fitted to board
Fitted to top of driver’s seat:
fitted ready to use
Just needs a radio and rotator controller:
ready for radios