Well, some quick mental arithmetic suggests to me that 12' is approx. 0.025 wavelength at 160 and 6' would be approx. 0.0125 wavelength. Pretty tight coupling it seems to me. - even if we double those fractions for 80m! Thus far, I don't think I've seen any indication of what the height of the tower is?
Charlie, K4OTV -----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of N1BUG Sent: Friday, September 06, 2013 10:16 PM To: [email protected] Subject: Re: Topband: Are stacked verticals feasible? On 09/06/2013 09:26 AM, ZR wrote: > I would think that at 6-12' spacing from the tower it would minimize interaction on 160 or 80? I don't know, Carl. I'll leave it to the experts. What I do know is I have made several attempts to erect a vertical for 80 meters near my 160 meter tower, using the same radial system. At 10 foot spacing from the tower, the base resistance of an 80 meter quarter wave vertical was less than 5 ohms. That to me suggests significant interaction with the tower. At 5 foot spacing the base resistance was less than 2 ohms! I don't have the data handy but I seem to recall having to adjust the length considerably from a quarter wavelength to cancel a reactive component. 73, Paul N1BUG _________________ Topband Reflector _________________ Topband Reflector
