SM7UZY



The city stealth antenna project



December 2018


When i lived in the city, i had no chance for any antennas outside. I did’t have any balcony or like that, just a flat on the 3:rd floor. But i had some stealth antennas for 2m/70cm and HF. Here are them.


The 2m/70 cm dipole



I used a 2m home made 5/8 inside my apartment for a while that worked... well.. ok. This 5/8 is really great outside for it’s size, but not inside. So i started to think of a stealth dipole outside my window because i had some problem to hit on direct frequencies.

So i grabbed some transparent acrylic plastic that i cut into small lengths that i used for the boom (i used two of them). Then i took some 1.4mm2 copper wire (insulated copper wire for coils) and made one dipole for 2m and one dipole for 70cm, connected together to RG-58 cable.
That’s it!

The length of the total 2m dipole is 0.980 M or 3ft. 2 - 5/8in. One leg is 0.490 M or 1ft. 7 - 5/16in.
The length of the 70cm dipole is 0.328 M or 1ft. 0 - 15/16in. One leg is 0.164 M or 0ft. 6 - 15/32in.

But make the legs longer, put up the antenna there you want it and then cut the legs to better SWR. The wall etc. will have an impact, but you can get a perfect SWR on this one, 1.1-1.2 without no problem if you have the antenna not to close the wall. I had mine about 35 cm from the wall.


If you stand on the street, you had to look really close to see the antenna, and look at it. Otherwise.. you did’t see it!

As you can see on the picture, you only see the RG-58 and the connector (tape), not the boom or the antenna wires. And yeah.. you can paint the cable and the connector for even more stealth.

This is just an dipole, but it work if you can't put up any antennas. I lived on the 3:rd floor and you couldn't see it.



The HF antennas




The HF antenna no. 1


I used the Difona antenna inside my apartment. You can read about the antenna here.


The HF antenna no. 2
Upcomming

The HF antenna no. 3
Upcomming