After a comment by Adam, VK2YK on 20m today, I was reminded that I had not posted this SWR plot since I moved the 20m radials about and got it happening. Well, as you can see its much improved now on 20m. The only way to fix 10m is to shorten the aluminum radials. Not sure I am keen to drop it and cut a CM or 2 off each radial LOL. Most of the needed parts of 10m is under 2:1, but if I get keen I will shorten them.
As far as the antenna goes, this is a huge improvement over what it used to be like with only 3 radials. Really, it needs 4 per band. Not the 1 per band it comes with.
Spots on RBN:
Not overly strong to anywhere, but its being heard and getting out.
Making antennas is a shit business LOL. I have never found it to be a fun aspect of the hobby. But as the focus of my dxcc chasing is moving to 10m and the fact that I have completed 20 and 15m using the same antenna I have been using for donkeys nuts, I figured it is time up upgrade to a Yagi. 3 elephants on 10m is a reasonable antenna and as you can see in the image below, I have all the tube sitting there as left overs.
After looking at the various design options, what crap I have on hand and the like, the easiest yagi for me to build is a through the boom design with a gamma match. So then, if i cannot build a gamma matched dipole for 2m on the bench, there is no way in hell that I could build a yagi for 10m.
I know this looks dodgy as, and that is because it is. Crap is held together with duct tape, love and a hope and a prayer. This is the 3rd edition of dicking about here. The gamma match calculators were, well to say the least, kind of fucking useless. So I isolated the variables and just went at it one variable at a time to see the effect they have. Added capacitance first, moved the tap point second and finally changed the distance between radiator and match and in the end, I think i got a bit of an understanding of what does what.
A few hours later and I have this plot, not bad all things considered, like is connected to a bit of wood in a vice, its got alloy tube really close to it, its right next to the work bench and its stapled together with duct tape. But, I think I am now able to take this knowledge and turn it into a 10m yagi. For shits and giggles I might take what I have here and turn out 4 elephants for 2m and point it at the local repeater for full quieting HAHAHA.
On 40m i use 40m quarter wave. Its a hellically wound wire on a sota beams light weight fiberglass poll. At each joint in the pole I have used electrical tape to stop the pole from collapsing in wind and rain. This is only temporary till I get arsed to drive into Brisbane and buy some aluminium tube. Or so i said 18 months ago LOL
Anyway, if you look closely the blue tape is evenly spaced out up the pole but is missing in places. When i taped the seams I taped all of them. I only noticed yesterday that some were missing, when I saw the thief in action.
A Satin Bower bird, who has his bower in my neighbors yard, flew in, landed sideways on the poll and started to undo the tape. He started by pulling with his beak to get a hold, then swung around the pole like it was a swing until the tape fully unraveled and he dropped to the ground. Then picked up his bounty and flew back to his bower hoping to impress his girlfriends.
My mistake? Using blue electrical tape. Satin Bower birds collect blue things. When it comes to blue things they are kleptomaniacs and this one has decided to steal my antenna. HAHAHAHA
Here he is in action, trying to steal the blue tape from my antenna. HAHAHA
Doing a permanent install of the 40m vertical that I use and figured it needed a radial plate to make it look all pretty like. So I made one out of some 2mm aluminium scrap i had laying about.
A little bit of marking out.
A little bit of cutting out with the grinder cause I was lazy.
And finally a little bit of drilled out and ready to rumble, I added the angled bracket for installing a balun, unun or a remote tuner on.
Actual doing stuff and building stuff ham radio kind of stuff has been rather absent from the blog for some time. Mostly I have been doing things around the house and in the garden. But I have fully reassembled the radio room now and have all my toys setup. Son inlaw the electrician was down a couple months back and connected all the power up that I ran. So The room is now A1, tip top and ridgy didge.
I have actually not been as absent from radio stuff as it might seem. There has been stuff going on in the background and others taking up a lot of my thinking time :), you know, old men need to think a lot or as the wife puts it, PROCRASTINATE.
So what has actually been taking up my thinking time is antennas. Namely, now i have the space and lack of noise, what am i going to do for the antenna situation. After lots of iterations and ideas, I think a beam is actually in my future, a dual band, maybe tri band yagi.
Sun spots are on the up, 10m has been open for days and 15m as well and they are only going to get better for the next 4 years, so i will start there. With that in mind, I needed to play with traps and trap design to get that solid in the mind so I can focus on the interesting part of mechanical design and engineering.
A trap is simple enough, its an inductor paralleled with a capacitor. So i knocked one up to test and play with for 29Mhz. 1.1uH and 27pF and well, it came out at 28Mhz but that’s ok, for now, its not like I can use a 50V cap on an antenna that’s seeing 100’s to 1000’s of volts, at one port. The actual cap used will be made from aluminum tube most likely.
Next is to make another and use them in a wire dipole and get that working dual band for 10 and 15m before i head to the big smoke and buy the tubing I need and other bits to make a yagi. I am not really an antenna guy, but sometimes one has just gotta do what they gotta do.