RE: [amsat-bb] Explain the RG62 thing to me, please...

["Howard Long" <howard@xxxxxxxxxxxxxx>]

Jim,

Adding to my previous answer, I failed to say that you might want to
consider the use of a Pawsey stub balun too between the antenna feed point
and the phasing/impedance matching section(s).

You could do this with two 1/4 wavelength pieces of RG-59 [75 ohm] inside
some small bore copper pipe.

Remember to take into account the velocity factors of the individual coax's.

RG-59 - 66%
RG-62 - 84%

                                                           |
                                                           |
                                 outer connected           |
                                    to pipe                |
                                       +-------------------+
                    ----1/4wl RG-59----+----1/4wl RG-59----+ inner connected
to pipe
                   /  phasing section  +------------------ |
                  /                        Pawsey stub     |
            1/4wl RG-62                    RG-59 inside    |
                /                          copper pipe     |
               /                                           |
-----50ohm-----
               \                        |
                \                       |
            1/4wl RG-62                 |
                  \                     |
                   \+-------------------+
                    +----1/4wl RG-59----+
                    +-------------------+
                         Pawsey stub    |
                                        |
                                        |
                                        |

73 Howard G6LVB

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