Recent content by nav2010

Try using Eznec to work out the reactance of the antenna when you have transmission line currents in parallel and in series with antenna currents simultaneously. Good luck.

Now imagine if we took this to an extreme as per pictured below. The vector sum half wave cross over would still be in the same location because of the dead short between the cone and the monopole at the base. Now you'd end up with massive cone and a short exposed stub and the cone angle would...

I'm not saying the crossover point has moved from half wave downward from the tip. On a 3/4 wave antenna it will always have the crossover point at half wave. If you have a half wave monopole above the basket and a quarter wave basket then the crossover point is level with the basket. What I'm...

Unless of course the antenna uses the top 1/8th wave of the basket in phase with the 3/8ths wave monopole leaving a quarter wave basket again below the phase crossover point.

Not strictly true. It's an open sleeve design similar to a folded dipole in electrical operation. They are not strictly radials but more like the shorter tuning stub on a J-pole but with more complex current and voltage patterns.

Why would you want the 1/4 wave basket version to perform better? An 1/8th wave extra on the basket ain't gonna cause any stability issues weather wise and you may have dropped on a unique design upon which you can further elaborate and experiment. You won't find that out until we do a one for...

Like thus

Technically it should be worse than the quarter wave because increasing the basket length reduces the length of the upper element akin to increasing the braid length of a coaxial dipole and shortening the upper element.......but - it's not a dipole and it doesn't deal with the same...

No this was in the United Kingdom

An important note: On Sirio tuning charts for this antenna, the tuning length is measured from the radials to the tip and not the length of the driven element.

My son ordered a Sirio Tornado 50-60 as a Xmas present for me. On opening the box on Xmas day I was presented with the correct paperwork for a 50-60 but the wrong antenna, they sent the Tornado 27 by mistake. Bob85 and myself discussed the options, it was either send it back with $25 shipping...

I would but its raining really bad, the swr has gone to hell again so the tape didn't work. My 11m dipole worked fine even in rain but had two aluminum radiators, this has a coaxial lower element and its shockingly poor in the rain.

...And the reason I know the choke is lowering the impedance rather than increasing it is because when it rained the vswr went up from 1.3:1 to 1.7:1 @ 50mhz. But it then tuned at 1.3:1 @ 47mhz which is an increase in electrical length. The upper radiator cannot change because its aluminum so...

I've just put the antenna up with an vswr of 1.3:1 There is rain forecast today so I'll see if the tape protects the choke from lowering the impedance. I didn't have this problem on my half wave dipole I made for 11m, I used two aluminum radiators which were centre fed and the coax ran up the...