Ever wanted to install a shortwave receiving antenna FAST?!!! Then I am almost sure that you will want to learn more about the “Inverted L” antenna… About the easiest effective skywire to build …
Just two supports… may be two masts, a mast and a tree, a mast and a nearby building… it need not be perfectly horizontal above ground… as a matter of fact if the inverted “L” is installed in a slightly tilted angle it seems to work better.
Although strictly speaking a true inverted L has the downlead connected to one end of the horizontal section… my version calls for connecting the downlead (a single wire) to a point about 20 percent from one end.
The antenna should be connected to your receiver via an antenna tuner with a real wide matching margin. For a 10 to 15 meter horizontal section, strung between two masts of about 5 to 7 meters each, you may expect very nice performance on frequencies extending from about 3 to 30 megahertz.
Using the inverted “L” for transmitting, does require the installation of a good ground system or a “floating counterpoise”, a device coming from the early days of radio that provides an amazing improvement in performance of many antennas…
You may want to build your inverted “L” with copper wire of no less than no. 16 gauge.. I prefer to use PVC covered copper wire of no 16 or no 14, same type as used by electricians for home installations.
Overall antenna length is not really critical, but the inverted “L” does need have a horizontal section of no less than 5 to 7 meters and a vertical section of no less than 3 to 5 meters to work effectively.
The most tested version here has a spacing between masts of 20 meters, a height above average terrain of no less than 5 meters and I used a single wire floating counterpoise, installed below the horizontal section of the antenna.
Do remember than in order to obtain optimum performance from this very simple, yet effective, short wave antenna, you do need to install it properly, solder the antenna downlead to the horizontal section, and use an ANTENNA TUNER…
Arnie Coro C02KK