click on photo for bigger size
For the use of HF bands i have made a wire antenna. I have mad this decision for i'm living in the center part of the village, which consists out of low buildings with small gardens. For me it's a big issue to even consider putting up a big tower in these surroundings.
Wire antenna's can be found in different shapes, like dipole, inverted V, with or without traps exc. exc.
I was looking for a practical solution and with the experience of other Ham's i came with this solution.
I was determent to make a maximum effort out of the possibilities, knowing that i could only construct 30 meter (98.4 ft) of wire. So i did put the maximum distance of 30 meter up, and on the frond end of my front garden put a 5 meter (16.4 ft) wooden pole up as at the back end of my rear garden to raise the legs of the antenna. This makes a inverted V made out of plasticized copper litze wire.
|
|
|
click on photo for bigger size |
||
It's a known fact that this kind of antenna needs a tuning device. For this antenna a homebrew a tuner on which you can find information here.
After a while working with this setup i came to the conclusion that the higher HF bands are hard to tune. For this problem i found a solution to make a secondary antenna of 2 times 3,5 meter (11,48 ft) on the same feed point. This combination is working fine.
The antenna is put up in may 2003 and in march 2004 i received a letter from the city council in which they mentioned that i illegally build a structure without a permit. In fact they mend the 5 meter (16.4 ft) poles in my frond an back garden (see photos). After i send in the application for the building permit the council dismissed this application on ground that the poles didn't comply with the standard in street scene and zoning plan, in spite of my well-founded reasons.
Now it was time to come in with the big guns in the form of a lawyer and a book called "amateur radio antennas, juridische leidraad" (translation "amateur radio antenna legal guideline"; a big book published by dutch radio amateur association about legalities on antenna's and towers).
This action had the result that the objection committee has ruled that the council didn't do it's job properly (read not interested in the case, typical bureaucratic stuff). This resulted in a building permit at last, issued 10 june 2005.
Back to the wire antenna. I wanted to use open wire for feed line and went for the cheapest for of this, make it yourself. I used the same plasticized copper litze wire. For spreader i used 5/8 inch pipe that we in holland use for putting in electrical wire, in which i drilled small holes to put the plasticized copper litze wire trough. To keep the spreaders in place i put a tyrap inside the spreader pipes around the wire. (see photo graphs below)
 |
 |
Click on picture for a bigger view |
|
Sa far so good, and now the last problem....... how on earth do i get the feed line into the shack, without compromising the impedance. On the Dutch amateur net on 80 meter someone told a story about this and had the solution to put two iron bars with thread right through the wall. On each end of those bars you can screw on the copper litze wire.
On a amateur really a bought some small insulators, witch i used on the wall.
 |
 |
Click on picture for a bigger view |
|
I'm working regularly with this installation and i'm happy with what i manage to make of it, considering the the little possibilities i have on this location.