Sirio Tornado 27 Antenna

[nav2010]

Like others have said, it is not a good idea to remove parts of an antenna that are part of its resonance. It could be done but you would more than likely have to re-tap the tuning coil to make it resonant with the driven element at the same height.
However, there may be a chance that you could compensate for that in a simple manner. There isn't much chance of you being able to work out the inductance of the radials you remove but what you could do is this:-
Measure them and make your mounting pole the exact same length as one of them, then get a piece of 4 inch plastic tube about 6 inch long and where your coax is parallel with the bottom of the mounting pole (antenna already launched) wind 6 turns of the coax around the plastic tube in a sequencial manner so than each turn is at the side of its previous turn (like a slinky coil). Tape it up so that you have a nice neat job.
You will never get the antenna to radiate in the way that it was designed but you might have a chance of making it happy electrically.

 

[hotrod]

I thought I would have the room for it, now I realize that I dont. The Sirio will fit if I make the radials short they are adjustable from 4 feet to 6 feet. I will try it with 4 feet and see what happens.

im thinking adjusting the lenth of the radials also tunes the antenna to some extent.
i maybe wrong ,not sure.far as getting hit by lighting ANY antenna even if its only 1 foot
could be hit by lighting.having it low does not guareentee anything.id mount the antenna
on your pole and attach it to the house on a coner of roof. then try turning your antenna
in a slight circle to see maybe you miught be able to straddle each radial between the
coner of roof.far as tuning if you have a mfj 259b i highly recommend you use it, or if you know any locals with one id ask them for help.cause if the radials do help tune the antenna
i dont think you,ll see it on a stndard swr meter

 

[pkmak12]

update on Sirio

I finally got the Sirio Tornado up its on a 18 foot mast and the bottom section is about 2 feet underneath the gutter line of the house which I will be raising the antenna up higher in a week or so above the roof line. So far compared to the Imax and A99 that I had which were alot higher they were 20 feet above the top of the roof, the Sirio out performs them both in Tx and Rx, very very little noise level, its one quiet antenna. I dont think I would ever go back to fiberglass again. Im actual looking at getting another Sirio as a back up antenna and toss my A99. Thanks to everyone for their advice and feed back.