Nebula tilt base progress 3/1/2021

So an early start pondering more programming and exam revision – have to say that I dont write a MSc blog, maybe i should… hmm. Anyhow more work on the Nebula today as soon as the sun came up and i could safely work in the daylight. First job, take down the 40m and 20m antennas I have been using for the last few weeks.

I was really happy how well both the dipole 40m and the buddipole vertical on 20m worked the last few weeks, they was quite quick to setup and kept me able to do the things I enjoy, also making telphony SSB contacts on 40m was great as well. I was glad that the buddipole went up with no damage and came down equally as well – I have packed it up nicely (as always!) for its next outing.

Having a free area to work in I started to measure up 5m diameters for the guying stakes to go in the ground. I started with the measurement from the guy I would ‘walk’ i.e. attach the last rope to, then work out the other angles/positions for the two attached. I was able to mount the nebula with relative ease onto the mast base, the scaffold diameter and length being ideal and not having any lateral movement.

I had not guyed any points yet as i wanted to be sure that the bolts and pivot action worked correctly. I created some temporary supports from the garden furniture we have, which proved to be an ideal height for the mast at rest. I noticed that the position of the mast the trees to the right would need some trimming back as not to catch the elements on when they was attached to the nebula.

I had already done one test run, but I asked my good lady to take some pics of me raising the nebula up, as you can see here, the tilt base is doing an excellent job and it makes raising and lowering the mast no harder than the ‘classic’.

Next i measured out the necessary positions of the guying stakes, i had enough room in all directions, but would require some pruning of the trees/bushes to allow access. The electric saw I used to cut the base-posts made light work of that and I was soon able to access the 5m distance from the mast to where the guying post is located. I also took down the other branches which would interfere with the mast as when doing the ‘test’ push could see they would constantly be tangled if I left them.

It took about 4-5 attempts to get the guy ropes the right lenght. I opted to use Mastrant-P 4mm diameter as I have used that in the past and can trust it to keep the mast up. As is I dont have enough to complete all the guying for point 2 & 4, so have ordered 100 meters more to compelete the guying. I will keep the guy rope callum provided for my other SOTA beams.

Having completed the first unsupported upright I then took it down until the additonal guying rope arrives. I’ve put up some posts around the mast to keep people safe and avoid any damage to the mast.

As it gets dark quite quickly here during the week and I have a massive backlog of Uni work to get thru I think the earliest I will have to work on the antenna again is the 9th/10th – my plans are for ‘during the week’

Complete the countersink for the bolt exterior nuts/washers. (A quick drill/cut job)

Waterproof the wood so it lasts as long as possible (due on Wednesday)

Measure 80/40/20m vertical elements and create (measuring outdoors/sun/daylight needed!)

Create radials for 80m (reckong on 8*10m to start with, i have *loads* of radials pre-made)

Then come Saturday/Sunday I should be able to get the 80m wire going vertical attach the radials and see what the initial S.W.R report is like !

Hopefully this will all come to frution, but depends on how well i’m doing with my assignments in the evening and the weather next weekend.

Until then, stay safe and hope to catch you on the airwaves soon !

73

Alan / 2E0FWE

Nebula tilt base progress 2/1/2021

Another sunny start to the day down here in IO90, having started the day early playing catchup to some cool python programming waiting for the sun to come up, i was soon out working on the nebula tilt base as soon as it was light ! (8:30 UTC).

I assembled my progress and tools and looked at the next steps, i always enjoy watching Calum’s videos so I could see where i am upto in the build. One thing stood out tho, there is a plate at the very bottom of the tilt base. See pics below from Callums videos.

I’m lucky enough to already own 2* Classic DX Commanders – I’ve used them in a very good parasitic array before, so i could identify the plate calum is using as the radiating plate for the classic. I headed out to the garden to source one !

So having sourced the required plate and safely keepng the parts so I only need another ground plate to get the classic working again, i set about checking that the plate would fit on the scaffold pole. Here I ran into an issue, my scaffold pole was thick in diameter, probably only as much as 1cm but enough that that the plate wouldnt slip over.

I used an offcut of scaffold as a template and tried to find the best way with the tools i have to cut a bigger hole, but excessively big, so it would still be a reasonable fit. I used the saw with a metal blade to make small 1cm depth cuts the circumference of the inner-circle, where i was then able to cut the ‘teeth away’. Sure enough, although it looked very ugly, it worked !

I marked out the part to ‘hack’ out so it fitted reasonbly ‘snug’ to the bolts and tilt, i ‘popped’ the base out the Nebula cap and fitted over. This looked like the same base as Callums ! I was making real progress ! Hurrah ! Now the time came to make the supports. I took the other end of the fence-post and cut it in two. This would give me an ok-ish 6cm either side to play with for supports, but then this is a nice bit of 10cmX10cm post.

Having made the supports i needed to get them onto the tilt, the wood is 10cm deep, and need about 5-6cm plus to make any kind of secure connection. I had a quick look online, but was coming up with nothing, darn, was making such good progress ! I am very reluctant to goto any shop, but needed to get this done, so headed to B&Q to get some essential screws. I found the staff incredbly helpful in helping me choose the best screw for the job (self-tapping wood, thickness/end screw type) which I wouldnt of been able to do via the internet, so although I was a bit stressed with going to the supermarket, i was glad of the help i got.

For the side-supports i used 4 self-tapping screws to start with 2 of them went in very easily, the othe 2 needed a ‘manual’ finish to tighten up. I think what helps the most is doing a manual ‘screw’ for 4-5 turns so the screw is nice and vertical, then going in with the dill. I liked the way the combo of a SDS/Manual chuck adapator worked with a torx screw holder, it saved me a fair bit of work !

I then used the last two bolts I had to attach the tilt-base to the pallet boad, these went in the easiest by far, and as you can see the result was really good in that the tiltbase had a very secure ‘ground’ to work from on the pallet.

tilt base in rough location

I then moved the tilt base to the ‘antenna’ area of the QTH, pointing it in the general direction of how i will walk it up. I made a short video that hopefully helps in explaning the positioning.

Having spent around 4 hours it was time to take my doggo for a walk !

I’m hoping for more good weather tomorrow and after tidying away the current 40m and 20m antennas to do a ‘test’ erection of the Nebula !

Until then stay safe and 73

Alan / 2E0FWE

Nebula Tilt Base Progress 1/1/2021

Firstly HAPPY NEW YEAR ! Ok, thats that done 🙂

Its a bank holiday here in the UK and I made good use of the lovely bright sunny morning to get cracking with work on the tilt-base for the Nebula. It gets dark pretty quick here now in the afternoon so maximizng daylight hours and me not getting too tired really means making good use of the free-time.

I set about getting my tools together I would need to continue the build. I had left it at the point where I didnt have metal drill bits and the ones I had ordered were not SDS, so then had to get a SDS adaptor. After a couple of minutes of working out how the adaptor fits, i was able to drill the hole in the scaffold pole. Have to say the drill bits done an excellent job cutting through the scaffold pole like it was butter !

Having now successfully drilled the hole through the scaffold cut off i spent a few more minutes watching callums tilt base video (will post again below for reference) – the next step was to construct the base.

https://youtu.be/v0xrqmoKC_s
Callums video on the construction of the tilt-over base

I was lucky enough to hold onto an old pallet that came with some goods i ordered on line, as there was no instruction or request to return it, I was able to use that. It had plenty of wood to cut down and move forward with the base construction. I already have a good electric handsaw, but its more designed for ‘flat’ cutting, so I purchased a Reciprocating Saw, HYCHIKA 18V Cordless Saw with 2x2000mAh – at £83.99 this is not ‘cheap’ but compared to other tools in the price range, it certianly is good value for money. I have ot say i was expecting it to be ‘will do the job’ but was really impressed that it came with two batteries (3/4 charged) and several wood and metal cutting blades. I can see myself using this tool alot on other projects, it certainly made light work of cutting up the bits i needed from the pallet !

Having cut the wood I wanted to get an idea of how ‘wide’ to make the base, so i popped around to see the Nebula mast and do my daily antenna inspection (yep, I check the knots/stakes are safe *every* day). Have to say the QTH antennas look quite seasonal.

Having got the Nebula radial plate i could then size up the base and fix it together. I have a number of electric drills, ironically the most expensive (Bosch) being utterly useless. I have a hand-held black and decker one and I added this electric screwdriver for £21.99 to the armoury of tools. Now for £21.99 you’d not really expect something that was particualy brilliant, in the video Callum uses a gorgeous Makita drill (envy) to get his screws in, but I have to say i was amazed that this little USB charged drill had plenty of torque to get the large screws into the wood. Only the last screw (which I think I put it in at an angle) required manual intervention.

Next I wanted to check i had got the holes aligned, and amazinly i had got them inline to about 50mm of each other. I did take a bit of a ‘wack’ with a lump-hammer to get the bolt thru, but sure enough, it went in !

testing the rod fits

Getting the rod out was interesting.. i used an old drill bit and hammered away, this did cause some slight damage to bolt, but nothing that wouldnt be seen or stop the build. I then went back to watch the you-tube video to work out the placement of the bolts and washers with the tube, making a sketch so i would get them on right.

At this point i could see that i have either drilled the whole too high up the pole or got a measurement wrong from the guesstimates made from the video. I was able to use the saw with a metal blade to shorten the scaffold pole so it would tilt fully.

I was now able to tilt the pole into position. I made some adjustments with the bolts and used the saw again to cut the excess off the bolt. By now my dog Sweety (yes hes a boy) was also after my attention and had been doing this for about 2-3 hours. I felt i had made really good progress and it was time to take Sweety for a walk and enjoy the afternoon with the missus 🙂

Having tidied up all the tools etc, I started to think about the next steps. I’m going to counter-sink the bolt-holes so they are not protruding and use some good all-weather protection for the wood. Next steps will be to secure the tilt-mechanisim to the larger pallet base, where by it should almost be ready to test out ! Hopefully the bright, but dry weather will continue over the weekend allow a few hours each day to get ever nearer completing and getting the Nebula up and operational !

Stay safe and 73

Alan / 2E0FWE