azraphale said:
Get a decent antenna and get it as high up as you can. If you wanna do mostly milair, get yourself a quality milair discone and mount it high, with the best quality coax you can get (and the shortest run!), would be my recommendation (for a single omni antenna that can cover the full milair band with fairly even gain throughout).
You have made my morning cup of coffee. So it is time to open up the mil antenna talk shop.
LOL, omni antennas with gain -- not gonna happen!! This myth has been pushed for years by manufacturers who wanted to make their omni antennas sound better on paper than the competition. A rubber duck antenna is a good antenna compared to the non-real antenna, but it is three db short of a dead short in my book.
In order to have true antenna gain you MUST have a directional antenna. I can make an omni appear to have gain over a theoretical antenna that doesn't exist or if I mount it on the side of a metal pole (creates directionality and thus gain). But with that scenario the antenna loses its omni characteristics which is most desirable in the milair world.
As for coax, there is also a point of diminishing returns. You can buy the most expensive coax in the world, and add the greatest preamp in the world, but if the scanner has a noise floor higher than what the coax and preamps provide, you have flushed it all down the drain.
Sorta like I need more receive signal and it is already full quieting on the receive end.
Hard line and other coaxes are a bear to work with, expensive (including connectors), and in "most" installations bring nothing more to the table.
If you are using an off the shelf consumer scanner for milair, then a nice omni or discone of your choice mounted clear of obstacles, some RG-6, and in some instances, a good low noise preamp may bring something to the table. But running out here spending big bucks on 9913, high dollar omni antennas and putting them at 50-100 feet into a Uniden BR-330 or some such, you have more money than sense and I could use some of your money. ;-)))
Now if we are talking milsats, totally different discussion. But that will be left for another day and another venue.
73 de Chief