Full and Half Size G5RV Antenna

You either love em or hate em. I have never heard anything else about a G5RV. Simply put a G5RV antenna is a compact multi band antenna for which the full size version is good for 3.5 Mhz all the way up to 28 Mhz for those thinking of bands thats 80m - 10m. The antenna is most efficient on 14Mhz - 20m especially if hoisted up where by its 34 ft off the ground which is around the optimum height for a 20m dipole.

Although it looks like a dipole and has about the same size of one it isnt. I wont go into the details of it all but to say it will allow you to go on all those bands and its a comprimised antenna. It wont outperform seperate dipoles cut to resonate on each band from 80-10m and neither does it give out the radiation pattern as a dipole-well at least not on all bands and requires a tuner to operate as its not perfectly matched on each band. But if you live in a constrictive lot like I do its better to have this up and be semi out of sight and be on all bands than to explain to the neighbours why you have 12 clothes lines up ;-)

Construction

Its fairly simple to make. Use the graphic below as a go by. The top section is two (2) wires each 51 feet long. Connected at the center is the matching section shown on the graphic as X. The matching section can be various type of wire. Preferably 300 Ohm windows type but can also be open wire and standard 300 Ohm wire. Use the guide below to find the length.

300 Ohm windowed type wire...30.6 feet
300 Ohm Standard.............28 feet
450 Ohm......................31.5 feet

At the end of this matching section attatch any regular 50 Ohm coax and feed it into your shack to your tuner, tune then talk.

Special Notes:

For this antenna to be at its greatest potential you should have the flat top straight like a dipole not an inverted V sort of shape. If the full antenna wont fit on your lot 10 feet off each end can be allowed to drop or slant down at some angle and performance will not be comprimized or at least not to any major extent. If and only if its a must to have the antenna sloped like an inverted V then do not slope the wires down any less than 120 degrees. If this is still difficult see the very bottom of this page on the 1/2 sizes version

The matching section should hand vertically all the way down from the top and not touch or be laid along the ground. You may slant or curl it upwards slightly to make it fit in a tight space but ideally it needs to be straight vertical.

Sometimes you may get higher than normal SWR, TVI, RFI, or some other type of interfearance. if so make a choke balun just back from where the coax cable meets the matching section. Make 6-10 turns of a radius roughly 6 inches. This will prevent or greatly minimize any feedback and interferance

Half (1/2) sized G5RV

To make a 1/2 sized version is simple. Take the measurements from above and divide by 2, just take each measurements and construct it exactly half of a full size version.

Due to the lesser size the 1/2 sized G5RV antenna will be operational from 7Mhz - 28Mhz or 40m - 10m. It is possible to operate the 1/2 sized version on 80M (3.5Mhz) however results are not as good. I personally use the 1/2 size version and the only time I use 80m is in the evening where we have a local province wide net and the 1/2 size antenna allows enough good output for that. However dont expect to work DX on 80 with it. Other than that its as great as its big brother