Author: RVZ via TowerTalk <towertalk@contesting.com>
Date: Tue, 15 Jan 2019 04:38:03 +0000 (UTC)
Guys, I've got a 160m. Inverted L with the vertical wire spaced 4' from a grounded steel tower at the base and 6' at the top. The radial system isn't perfect but it's decent. Based upon the Inv. L'
On 1/14/2019 8:38 PM, RVZ via TowerTalk wrote: 1) I'd appreciate some guestimates on what percentage of input power may be getting shorted to ground? 2) Any guestimate on what percentage of power may
How tall is the tower? The taller it is the more power is likely coupled to the tower. I can try it in EZNEC+ if I know the height of the tower, the diameter of the tower, and the diameter of the w
In Illinois I hung a vertical wire off of a Phillystran cable many feet away from the tower and had good results. My model showed that the tower slightly skewed the pattern, if I recall the tower act
My thoughts would be the following on this: Bringing the feed point about 20 - 25 ft away from the tower and letting it slope up to the high point would help to de-couple. Obviously the radial system
Where does the idea come from that a grounded tower holding up an inverted L is a problem. Is this just some notion that took hold? The tower is some how an RF sponge? Hams have been doing this for d
Pretty much this. I modeled K9OM's setup for him, and although I couldn't accurately copy his ground conditions and radial field, the model said there was virtually no interaction at all. He doesn'
From the work done by K2AV in conjunction with the FCP: http://k2av.com/ In particular, pay attention to the information on a *separately* fed inverted L (with or without the FCP) hung off the side o
On 1/16/2019 9:43 AM, Rob Atkinson wrote: Where does the idea come from that a grounded tower holding up an inverted L is a problem. Is this just some notion that took hold? The tower is some how an
That's not true. It matters a lot. Compare a 125 ft tower that is insulated at the base with one that is grounded at the base. On 160M, the grounded tower is near resonance, but nearly an open circui
Hi, Jim. That's not what I meant, and I think you probably know that. But yes, I should have been more precise like I often preach. ;) What I meant was in the context of my comparison to elements f
I put the base even a little further away than that so lower antennas can rotate and there is less coupling. From my modeling the tower can skew the pattern even 100+ feet away. Antenna placement is
Hi Dave, Do you mean that with the tower tuned to 160 it seems to become a reflector?? Many Thanks for your info on this subject... 73, Ted K2QMF _____________________________________________________