Antennas
How I made my two metre HB9CV
Antennas have been constructed for 6 4 and 2 metres, 70 and 23cms but with varying degrees of success. At the moment there are only two homemade base station antennas in use, a 4metre HB9CV (centre antenna on mast) and a 6metre ¼ wave, but in over twenty years of mobile operating I have never used any commercial mobile aerial, it is probably why you can hardly hear me!
Horizontal and Vertical
Here is how I can change from horizontal to vertical polarization and back with just the one antenna.
In the photos you can see the cross boom that is pivoted at the main mast. At both antennas I have attached a length of string, yes string I find it lasts well outside, with this string I can pull the cross boom and turn it through 90degs resulting in either horizontal or vertical polarization or any angle in between.
17metre Mobile antenna
The tube The coils
The tube that runs the length of my van contains copper pipes. It is also my 17metre mobile antenna!
Wound on the end of the tube are several turns of multi stranded wire, in front of them another coil has been wound around a former allowing it to slide back and forth enabling me to tune the antenna to a near prefect match. From the second coil a length of wire runs along the top of the tube, it is about 3metres long. When I have to add or remove copper pipe from the tube, the antenna can be easily retuned by adjusting the position of the second coil.
How efficient it is I do not know but I have had 59 from Sweden, Estonia and SP with the 10watts that humble M3s are allowed. As the coils are wound now, I can also match on 15metres and I suppose that with a different number of turns etc I could match it on other bands as well. I might just try that one day!
Any suggestions as to how I can turn this tube, containing copper pipes, into an efficient antenna on any band would be very welcome!
