So with us coming out of winter into Spring (20/3) I really wanted to tidy up. And tidy up everything. My shack had become a really bad ‘mess’ and as an engineer/student/professional this is my ‘small home office’. I’ve had used these Keter Store-It Out Midi Outdoor Plastic Garden Storage Shed around my back garden for storing various things and they have proved really good, in capacity and being waterproof. With an electric screw driver i was able to put it up and thanks to a mild Friday evening, started filling it. Swiftly I had reclaimed my floor and alot of other space in the shack/office 🙂 I then turned my attention to outside the office !
With the bad weather forecast I had already lowered my Nebula, as it look pretty high wind forecasts. I’m pretty sure my mast would of been ok, but I don’t like to take a risk where its not necessary, so the best part of the week I was without HF on my main right (IC7300). The end fed antenna for receiving Weefax was still doing a grand job thou pulling in the images
I took the opportunity to inspect the Nebula and i noticed the main pivot bolt had got seriously bent out of shape, so I took the decision that i would have to rebuild the swivel base with a much larger bolt for the scaffold pole to go thru. I six hours then tidying down the Nebula and al its components. I think for now I wil keep my DX Commanders (I Now have 4) for when I can construct a full phased array with them. I know how good the Nebula is and the classic, so getting a phased array for amazing DX. What I do have now thou is a lovely clear garden, free from antennas apart from my 40m dipole for WSPR and my end fed an NVIS heights for RX.
I have a staggering amount of uni work going on as well as work-work, and I feel that i could get my shack and all my equipment really in tip-top order before mounting another antenna, be it HF, UHF or VHF. Hopefully the weather and longer evenings will mean that I’m not off the air for long (other than WSPR) and soon trying out a new and exciting antenna.
So its already ‘hump’ day (aka Wednesday) – i’ve had very little time to even go outdoors and the weather is being typically English.
I did get a chance to survey the Nebula as to what work can be undertaken this weekend, well looking like Sunday is my best hope !
So i think i will replace several elements with fresh wire from the Nebula kit. I will measure the wire in place. I think its physically stretched hence why it has become so slack. There was quite a gale blowing last week, so maybe it got stretched then ? I will take measurements and replace either way. I will also be taking more time with the guying and guying the mast where ever i can to ensure the wires cannot stretch again (if thats the case).
So list of work for the Nebula this week
Remake 80, 60 and 20m elements
Guy/Tether spreader plates at 1,2,3, 4 and 5 if carabinas fit
So I’m looking forward to hopefully some sun/dry weather. I’ve got another project going on with the bongo, but not all the parts are here yet, but it will be nice to have a cross over between bongo and hamradio blogs !
The weather in the QTH has been particularly bad for the past week and the opptunity to do any amateur radio activties overtaken by university assignments. Thankfully today though, both the weather and a bit of respite in the amount of course work to do meant i could focus on the nebula.
Having operated 80, 40 and 20 the next step was to multiband the nebula. I’ve done various configs on the DX Commander Classic before (adding 80 as L, different band makeups) but this was my first time with the Nebula in moving elements and adding new ones. As ever my first port of call was the instructions to review what was ahead to get from 3 to 6 bands.
I set out first thing in the morning, probably around 8, to start measuring the elements. The surveyor’s tape measure really is great for these long pieces of wire and getting the lengths right. My ad-hoc spool shystem formed from some mast brackets and securing pin done the job in being able to pull the wire off easily. Note the nebula still had its existing 80, 40 and 20 meter elements. These would be taken off with all the tape/elastic as well as they would need repositioning.
I set about cutting the longest element first, being for 60m. I cut longer and trim, based on experience this allows to get it close to the lengths required. As you can see the sun was coming up and thats not smoke from the fire, thats the ice evaporating ! As you can see the Nebula had a good amount of ice on it from how cold it had been overnight, and was still quite chilly in the morning !
With the lengths of wire cut for the new elements, i returned to the ‘shack’ and stripped the wire to fit into the connectors. I stip/tin, then crimp to ensure electical connectivity and mechanical strength.
I started with the 80 meter element, by far the longest, and most complex to get right. I do not like ‘floppy’ wires for elements, so I have a good amount of tension. Getting enough ‘slack’ into the top takes a bit of time and install fettling to get right, but taking time and getting the right lengths of elasticcord makes a big difference. I was able to get good tension on my 80m elements and even should the wind blow hard causing the mast to ‘flex’ it will enough ‘give’ to not snap/come off.
I repeated this for all the other elements. The process I used was to first to re-markup the vertical plate at the base of the mast, then rotate the spreaders, using the ‘dx commander; stickers as visual line up, I was able to install all elements quite easily, even 60 was ok to install despite its length. I had run out of paracord, but getting the tenion in the rope has done the trick for 17m and 20m verticals.
As you can see from the Rigexpert output SWR results are satisfactory to excellent. All the bands where I have elements are tuneable on the IC-7300’s internal tuner, and in some cases not even needed. I was amazed at the results for 60m, being a ‘new’ element to me on how well the SWR was. 10 and 6m look good as well, but think with a dipole conditions would need to be very good in the ‘E-Layer’ t pick up any signals.
The S.W.R. reports for each frequncy mid-band demonstrated the effectiveness of the Nebula. As a Intermediate licence holder, i cannot transmit on 5Mhz, but I will tune in and listen for sure ! I think the SWR’s for all the bands is quite acceptable.
When I’m not using my radio, or my antenna is down, i put this dummy load on. Whilst not rated for 100W, its better than not having anything on there. I’ve never tried to transmit without an antenna in place, but this strikes me as a good idea to ensure the longevity of the rig..
By now i had taken our dog Sweety for a walk, as well a few bits and bobs around the house. I do enjoy taking a break and having a cup of tea with me missus, it keeps things at a sane pace.
I knew at around mid-aftenoon it would be slightly close to get the antenna fully vertical and all the radials reattached before night came along, thankfully we are getting slightly more sun now and dusk is getting later everyday (well until the clocks go back…)
I was really happy with how I ahd really enjoyed the build and the results from it in acceptable S.W.R. readings on the desired bands. The tilt-base was awesome and I finding easier and easier to get the mast vertical and guyed each time.
The Nebula is my most recent additon in terms of antennas, but I’m very confident it will be one that i will be using for many, many years.
Heres a video of the mast up with all the elements attached.
At last the nebula is vertical and with 80, 40 and 20m elements added. I had a very hard time de-tangling the radials and manged to get 3 out of the ‘ball’ of wire i had managed to produce.
Adding 40 and 20 was quite straight forward and same process as on the classic. I dare say i could re-use the old vertical elements from the classic on the nebula, but its nice to start a fresh.
With just 3 sets of radials (4*10m wire each) i set about putting the antenna analyzer to work !
Initial results are very encouraging, I’m happy that the S.W.R. readings are close to what they should be, esp as the full set of radials isnt in place. I was able to test (and tune) easily on 80/40 and 20, making sucessive QSO’s on FT8 around Europe.
I still have all the radials from the ‘classic’ and these had worked well before on both 80 and 40m, so in the last bit of sunlight added these to tne Nebula. The results speak for themselves
I then wanted to experiement with some of the features of the rig-expert i seldom use, low SWR is often good enough for me, but as I’m going to upgrade the feed cable, went and got more measurements.
Now I’ll be the first to say I dont understand all the metrics on here, but I know that the return Loss of 19.9dB is very good !, likewise I’m happy with 11 and 10 for 80 and 20 metes as well.
I will find out more on what the other values mean.
Very happy with the clear reading sfrom the SWR meeter on the Rig Expert. I’m hoping i can get 80 and 20 even lower SWR and better return loss.
The all band analysis gave me a good visual on where the Nebula was resonant with just 3 elements. I’m looking forward to taking it upto 6, but with just 80, 40 and 20 these ar ethe main bands I use, so am happy with them. I could pull out my MFJ ATU – which I used to use to get me on top-band easily, so will see how i get on.
I’m going to manufacture the new feed lines, i’ve heard such good things about the coax and M&P connectors, i cant wait to see what happens.
End of the day I’m hugely satisified with how the Nebula is performing.
So as Storm Chistoph arrived in the UK the chances of any vertical work was off the planning today. At 8AM the weather looked abysmal with gusts and rain prevaling. I’m not adverse to bad weather, but given the limited time, risk factors and no real urgency to do this, held back on any vertical work.
When the rain did stop, i got out and measured the distance between the shack and mast base.
At approximately 7m, i think 10m to the shack and a 1 meter post-filter will give me enough ‘length’ to play with. The db loss of the cable is really impressive, you get what you pay for with M&P. I am looking forward to learning more on my antenna analyzer on how to measure cable performance as well.
I got as far as lifting the reel of cable from its resting place (think its nov/dec when it arrived!) but the bad weather and lack of time really prevented me from even cutting the cable to length, and didn’t fancy doing it indoors due to the size/weight of the reel.
I’m glad i got one small thing done despite the weather and am hoping that the rain and wind will stop before the weekend so i can do some testing on 80m
Another fine day of English weather, typical for the season herald the morning. Having been up early to start the bread-mix off, i set the alarm for day-break at 8AM. It was still quiet dark, but enough that i could wipe the mast down and look at the next set of tensioners for the 80m wire.
The initial tensioner at the 3rd spreader plate had held up over night, and was pretty good, having wiped the mast down to remove any moisture/rain i looked at the 4th and 5th plates for the next set of tensioning. I dont mind saying that i found it more wordy than how-to, so i watch Calum’s video again on how he done it and tried to remember how to do it out in the garden !
I managed to get the intial tension into the 4th spreader, and by now the aroma of bread was fillng the house. I took the bread out onto a rack to fim up and then tided up ready for a day of work – cant complain for 50 minutes of time – i like making small, steady progress.
By now panda (aka Monica) had woken up for her breakfast, we both really enjoy havign fresh home made bread with no salt or sugar in it, it tastes lovely and is safe for both of us. I popped out to look at what i could do during lunch, and put the pipe-tube tensioner on to give me an idea of how all the upper side tensioner should work.. but to be honest i was still quite confused of how to get some decent tension.
I spent my lunch break putting in the tensioners for the 4th and 5th plates. I don’t mind saying i found this quite stressful as I really wasn’t happy with the tension I had compared to what Callum had in his video.
By now i was honestly a bit miffed by it all and was eager to get back in with my day-job. I felt i had made some progress, but I wasnt very happy with the tension of the wire and also worried that the ‘doubling’ for the loops will create a linear load that will off-set the S.W.R. readings.
I came in, a little frustrated, but still glad i had made some progress midweek. The weather tomorrow looks quite abysmal with warnings for rain and wind where the next thing i have to do is to vertically erect the mast and guy it, before adding all the radials.
I will see how things are tomorrow morning, the worst thing would be to catch a cold/cough in the current climate and I’m not adverse to finding other ways to progress. The forecast for the weekend looks promising, but if anything this has been a ‘standard’ documented build so far, what comes next is the hard part, with all the unknowns of wire-lengths, loops and metal guy wires that could effect how the antenna performs..
Even thou a monday, i took advantage of the pre-daytime WFH sunshine to get small amounts of progress on the antenna.
I set about alining the radial plate and spreader plates. I actually make use of the ‘DX Commander’ stickers as an easy visual way of aligning the spreader plates, whilst I do have each of the vertical holes labelled (80/40/20) its still easier to see the stickers from a distance.
I threaded the 80 meter wire thru the top eyelet, which by now was totally rock-solid on the mast.
I also used my lunch break to attach the SO-230 – i found the tape very fiddly to work with, but nevertheless got it on to waterproof the connector. I’ve left the shield on for now. I then started on putting the tensioner loops into the 80m wire, which took me a bit longer than expected (sorry no photos!). but got the first one done at the 3 spreader.
I’m hoping the weather is ok tomorrow morning and I can get the last of the tension loops on the 80m wire in place, and all being well, get the mast vertical with the 80m wire going up it. A know the radials will take plenty of time to get out, so whilst I’m optimistic i might get a S.W.R. test tomorrow, realistically the first reading might not be until Wednesday.
So I treated myself to a bit of a lay-in this Sunday, which for me is getting back into bed at 6 when i usually wake up, At 8 it was a gorgeous sunny morning and I was full of get-up-and go to complete the final bit of rigging/guying for the antenna.
There was some tension in the top spreader as can be seen in the final picture, but i know that slacking that off will give me a nice straight vertical. It took me about 30 minutes to complete, but its a quesiton of being safe and methodical.
Next was to start the construction of the radial elements, i had brought these into the shack and they was already creating a quite bit of mess and getting tangled.
When dealing with this much wire, its essential to have a process and method, else wire/construction materials just get all over the shack and making working not the fun it should be.
So i wanted to keep 4 radials to one connector so seperated them out that way from the big ‘rats nest’ of wire i had. I then stripped, tinned and when all four were tinned, inserted them into the lug. I could then use the glue-tube and some tape to keep everything waterproof. With all four radials on, i would then take them out the shack to the garden, ensurign a ‘clear’ workspace to continue working.
By now it was getting close to 4 and the time to tidy up and think about what i would do in the coming week. I was really pleased with my progress today, albeit not quite transmitting, but with a well rigged antenna and the majority of the radials (batch 1) completed.
I used the industial strength superglue to attach the fish-eye for the 80m wire to loop thru and tidied the ropes on the upper two spreaders. Keeping things as tidy as I can helps with getting the mast vertical well and reduces any tangles/issues with getting it vertical.
So I have a few more radials to make up to get the full compliment of 30*10m ready, then completing the vertical construction with loops/hooks and feeding. Having built the ‘classic’ and Callums videos, I’m sure this will be quite straightforward.
I’m hoping that this time next week I’m measuring SWR on 80, 40 and 20 meter bands and they are close to being useable, if not perfect, but I know things can not always go to plan !
Heres looking forward to getting the Nebula on air – i think some form of naming ceremony will be required 🙂
So following on from the mid-week rigging exercise I could see some more adjustments would be required before adding elements or radials. I set about with my trusty spirit level and a whole load of energy to get the nebula as straight as i can.
So it was quite clear with the spirit level the direction and severity of the tilt that had to be overcome. I set about correcting the lenghts of the lowest ropes.
A bit of patience and some re-tying and adjust lengths soon had the mast in a better vertical postion when attached from the bottom most rigging point. I then set about the 2nd stage.
The caribinas for the second stage attachement are just about visible in the above picture. What I learned from the previous days rigging is that when attaching the ropes at this level I hneed to detach them each time from the ground stakes each time. Whilst this takes time, its stop a tangled mess and getting caught around the house, its more imprortant to take time and get it right, then rush and make a mess/get it wrong.
By now i was getting a little tired, and had quite a few other things to do (including walking me doggo sweety) – with the mild weather it was nice to get a socially-distanced walk and enjoy the flowers in the gardens in our neighbourhood. I came back home and had a good rest before attempting the next stage of guying as its quite suprsing how much effort/energy it takes to raise and lower the mast each time.
So the mast was looking far more aligned and well tethered vertically as I attached each level. The downside to this is that the trees do tend to tangle the ropes each time, but no real hardship in getting them untangled. I will be glad when I dont need to bring it down quite so much though !
As you can see the higher i go, the more the house blocks the ropes passage. Whats good about taking time is that as each time I do this, I get more used to simply unclipping the carabinas from each section. It is tiring with lifitng the nebula each time, but it was satisfying to see the rigging going so well.
So the days are getting ever so slightly longer, where it used to be pitch black quite quickly from 4pm, its staying brighter that little bit longer. I had guyed all the lower sections but still had one last rope on the highest section. At this time I thought, i’m tired, it will soon be dark and i need to get the mast back down safely and packup for the evening.
I done just that and have everything ready to get the last rope in place tomorrow. I will re-measure the vertical alingment with the spirit level once more, but its looking far better than it did, ensuring the mast will stay up in inclement weather. I’ve not had the time to solder radials or verticals yet due to uni assignments/exam revision, but am hopeful i can make some headway into that tomorrow as well.
Was lucky enough to have a few extra hours of sunlight to get work on the antenna done as my house was having an electrical certification inspection (i.e. no power on at all) for a couple of hours.
In that time i set about rigging the rest of the nebula !
One thing I did not anticipate is how much the trees would interfere with the rope. I was glad i had this extra hour or two to take my time and just focus/learn about the rigging. I started off with the ‘^’ of the triangle in the rigging on stage 2, that went really well with the rope and could hitch it with a carabina no problem. Continuing with the nearside left hitch point, which is too tight, i was able to connect this to stage 2 without problem, where as stage 2 right side required a bit of work to get the rope thru the trees, but a quick bit of of trimming and I was connected !
The mast was quite a bit off center, but it was good to practice and see where this was. Having not ‘rigged’ a mast this tall before it was a question of take it down and put it up each time to get the rope lengths in a good approximate distance. This worked reasonably well and I’m building up a better procedure of bringing the mast down without tangling the ropes.
Undoubtedly I will need to spend more time on the ropes to give them a better ‘balance’ I think the main culpurate is the bottom left point (if you draw a ^ and take the tip as front-center). AS the guying distance is just before 5m its slightly asked compared to the other amount of seperation the other guy-stakes have, but I will be able to correct this so it doesn’t ‘tug’ at the mast and it will be vertical in all directions.
Overall for an hours work i was happy to get all the guy ropes attached. The picture above exaggerates the tilt somewhat as its on .5 zoom and naturally ‘bends’ the shot somewhat more (as you can tell from the bricks in the house). I will get my spirit level out and get the mast truly vertical and set about adding the vertical elements.
Still, i’m still learning and enjoying every moment of it. Fingers crossed will have the nebula on the air not before too long !