Synchronus transformmer.

[tree@cmicro.com (Larry Tyree)]

The JULY-AUGUST 1981 issue of the NCJ shows how to make one.  I have used
these to convert 75 Ohms to 50 Ohms.  If you don't have the NCJ, cut
0.08165 wavelength lengths of 50 Ohm coax and 75 Ohm coax (mind your
velocity factors!!).  Splice them together and connect the 75 Ohm end to
your 50 Ohm load/tranmistter and connect the 50 Ohm end to your hardline.

The NCJ shows the following lengths for Regular RG8/11 or foam RG8/11:

         regular (.66VF)        foam (.79VF)
    80M    14' 8"                 17' 7"
    40M     7' 5"                 8' 10"
    20M     3' 9"                 4'  6"
    15M     30"                   36"
    10M     22"                   27"

They work!!

Tree  N6TR