G5RV JUNIOR

 I've been away for a long time. Haven't run across much that I thought was worth posting until now.

I was running EZNEC simulation on a G5RV Junior yesterday and ran into the following. I simulated 40 through 10 meters on a friend's proposed installation. The plan was to put the center at 24 feet and the ends at 10 feet. The following graph shows the problem with 10 meters with that installation.

Definitely not a good DX antenna and 28 MHZ is too high frequency for NVIS operation. So I changed the simulation so the ends of the antenna are at 20 feet. 

Certainly a more acceptable installation for 28 MHz. 

All of the lower frequencies bands provide a more acceptable patterns even with the ends at 10 feet and moving the ends up to 20 feet made little difference to the lower bands.

Turns out even raising the entire antenna by 5 feet produces an acceptable pattern.

Just thought you'd find this interesting and hopefully useful.

UPDATE TO FEED LINE CHOKE FROM COAX

 I recently received an email from a reader asking to what the Length in the following chart referred.

Admittedly at first I was at a loss to answer his question. It refers to the height of the coil when using RG-174. Poor choice of a word on my part. Length should be replaced with height throughout the paper.

The following chart gives a list of coaxial line chokes for various ham bands. 

      Turns         Diameter*         Height*     Coax type         Band Coverage

      13             8                   3.25           RG-174           160 meters only

                                                              RG-58

                                                              RG-8x

      9              9                    3                RG-174           80 meters only

                                                              RG-58

                                                              RG-8x

      8              6                    2                RG-174           40 meters only

                                                              RG-58

                                                              RG-8x

      9             4                    2.25            RG-174          40 – 30 meters

                                                              RG-58

                                                              RG-8x

      8            4                    2                  RG-174         30 – 20 meters

                                                              RG-58

                                                              RG-8x

      5            5                    2                  RG-174         20 - 15 meters

                                                              RG-58

                                                              RG-8x

     6             4                    2                  RG-174         17 - 10 meters

                                                              RG-58

                                                              RG-8x

     4             3                    1                  RG-174         6 meters only

                                                              RG-58

                                                              RG-8x

  * -   Height and Diameter are in inches.

Thanks for pointing it out Tim.

Thirteen of RG-174 is 1.43 inches high. You will need to space the turns to achieve a coil height of 3.25 inches.