I have a 20m dipole in my attic. As a stand-alone antenna it is resonant at about 48 ohms. I installed another antenna that runs parallel to it. The second antenna is a compact 40m dipole, where one leg is a 1/4 wavelength wire and the other leg is a 3-foot 40m mobile hamstick. It is resonant at 54 ohms. The two antennas are not connected to each other - they each have their own feedpoint. I don't have any feedlines or baluns connected to them yet. Their separation varies between 8 and 14 inches. With the 40m antenna installed I connected the analyzer to the 20m antenna again. I was shocked to see that now the 20m dipole was not resonant anymore, anywhere! It is as if the parallel 40m dipole has de-tuned the 20m dipole. Can these parallel antennas be made to work together? If so, should their spacing be closer together or farther apart? Should I use spacers between them to keep them apart at a consistent distance? If so, how close should they be?