We are almost done. Now on the last step we have to measure the SWR and cut the antenna to the right lengh.
We will have to put the antenna to some height. I have choosen a 10m fiberglass mast and an Umbrella stand.
You will have to put the antenna up and down a lot so if you are not usig a foldable mast make sure you can put the antenna up and down easily. I have choosen a inverted V setup.
Get your SWR analyser or a radio with a SWR Meter and set it to the 10m band. I have choosen a center frequency of 29mhz.
Tune for the lowest SWR on your Analyser. When the frequency is under (in our case 29mhz) you have to shorten the antenna. If the frequency is over your intended frequency you should make the antenna longer. Wich would be bad.
Now if the antenna is too long let the centerpiece down and cut the same lengh of wire away on both sides. I have began with about 4cm. Just loose the knot a little, make the antenna shorter and tighten the knot again a little.
Not put the antenna up again and measure again.
Do this to get a good swr (i would say 1.0-1.3)
When the first band is ok let the antenna down again. Unisolate both wires on the first isolator and connect them by twisting them together.
Now put the antenna up again. Set your analyser for the 20m band (in my case i choose a frequency of 14.200mhz).
Now again measure the SWR and shorten the wire for a good SWR.
Do this for every band until you have a good SWR on the 80m band.
We are almost done. It took me about 2 hours but it was my first try and i fckd up one time by closing the connection on one band and a different on the other side. 🙂
When you are done solder your connectors on the unisolated wires. I have choosen some small banana plugs but you can also use some crocodile clips or something similar.
Now we are done. 🙂
Wind the wires on the centerpiece and wait for some good weather to try your new antenna in the nature.
So we have all the parts and the wires cut to a lengh where we have a little spare lengh.
Solder on the cables for the 10m Band a Ring and secure it with the nut where the cables from the Balun are mounted.
Put the wire throu the upper hole and make a secure knot. Make sure you have a little spare wire so there is no force on the ring on the screw.
Put a knot on the wire like on the picture.
Now, on the other side of the isolator put the wire from the 20m Band. Go on for every wire from every band until you reached the wire for the 80m Band.
On the last isolator put about 4m of some kind of string. I have chose some thick fishing wire. On the other side of the string put a loop for fixing it later.
On may 1st was the yearly All Austrian Contest. The goal in this Contest is to reach as many Austrian Stations as possible. You get multipliers for every new district, for a stations from the state and when you operate with a power supply off the grid.
This year was the first time i participated in this Contest and it was a Hell of a lot fun. 🙂
The location i have chosen was our small “chalet” on a mountainside where i life.
The main thing why i have chosen that location is because we have a water turbine on there. All energy needed there comes 100% off the grid wich is nice because of the extra multiplier. 😉
The antenna i wanted to use was a NVIS antenna that i have build according to a pdf from OE7OPJ. I was using i 3d printed Topcap. You can find the designfiles for 3d printing on Thingiverse.
The feederline was 45m long Coax Cable. I put the coax cable on some electric fence posts so it doesnt lay on the ground and gets wet.
On 6 in the morning local Time the next day i drove again to my improvised shack to setup my Station. I have chosen to use my “Portable/Emergency Station”.
In total i have made 57 contacts in the first period and 78 contacts in the second period. I have only worked on 80m because the 40m band didnt work that day. (At least not for me ;))
I dont know if that is good or bad and i would really like some comments from other participants to see their results.
As said before. It was my first contest and it made a lot of fun. I am looking foreward to next year. =)