Where to start?
Placing two antennas 4 inches apart will affect performance on both. Bad idea. Rule of thumb; place antennas at least 1/2 wavelength apart on lowest frequency. In this case 1 meter apart.
If you want a dual band antenna build or buy one. If you are using two radios, with one on each band, or a radio with a seperate port for each antenna, be aware that transmitting on 2m may desense the 440 receiver. This is a common issue for satellite ops. Typical solution is to use a filter or isolator.
Author of: Mr. Fred, Nuke This Forum (Danger Close)