* * * VERTICAL 10/40 MT FOR PORTABLE, by IK4DCS * * *

 

 

               PORTABLE 10/40 MT. VERTICAL  GOOD ALSO FOR THE CAR RACK.

Since I got started with my activity connected to the DCI (Italian Castles Award)
and decided also to become an active "activator", It was necessary to prepare 
the most suitable antenna to that purpose.
The usual 10/40 crossed dipole mounted at the end of a fishing rod limited so
much the possibility of quick displacements in case of passengers on the car.
I therefore made up my mind that a vertical would solve this problem, but, of
course, not a usual vertical.
The necessity of rapidly passing from one band to another compelled me to create 
a 10 to 40 mt. single rod antenna.
So, what to do?

 
Go down into the  garage , put everithing upside down looking for that 
special trap that had to be there since long.
And there it is, full uf dust, with some spider inside, of course. Just clean it
and there it is as if it was new! A trap for 10/15/20 mt.
Then....where is that damn car rack that I used so many times for my several 
house changes? There it is, in that dark corner!
Ok, let's get started! 
Just take a metal plate and fix it to the vertical base.
Take the necessary pipe for the 10 mt., calibrate it and then mount the trap. 
Check the situation of 20 mt.and:  everything is ok.
At this stage you must make a trap  with a coax cable for the 20 mt, couple it to 
the vertical and check that this does not change  the resonance frequency of 20 mt.
So prepared, the antenna  could stand up without any problem but, for using it 
on 40 mt. you should make it a little longer.  But not to make it too long, 
I used a capacitive hat using two pieces of unipolar cable of 2 mt. each fixing
them to the car bumpers with a rope.

 
Then I put on a 1:1 balun and made the grounding of RTX by means
of a couple of unipolar cable and a steel rod of 30 cm. 
With this antenna I have no more problems, I can go anywhere, rapidly, since 
I can lay it down  on the car-rack during my displacements, and the be quickly 
back on the air. This solution takes also no room inside the car in case
of any passenger.
The antenna works very well also without any grounding but in this case you may 
have RF problems on your microphone.
The scores and results I had with this antenna where also better than
expected. Give a glance to my logs for DCI Ref. MN054,MO040,MO053/054/055 and RE027
and you will understand what I am talking about.
I must admit that even if self-made in the barn and not being so invisible,
it is really a good antenna.
My friends, I remain, as usual, at full disposal for any further information.
Update for GP 20/40 mt
                              
Considering the insufficient presence of interested to the DCI
on other frequencies, the vertical  in issue has become only 
for 20 and 40 mt.
The total length of the stilo becomes clearly more along, having
to work directly in 20 mt like first band, but 5 mt they are 
supported comfortably always with the same system used previously
for the connection between stilo and luggage rack .
The trap for the 20 mt we already have, therefore it does’nt remain
that to hoist all, add a good ground for the present usual RF and
begin to call CQ DX!

Good dx!

IK4DCS - Franco