MAY 1973

       Hank Holbrook, 7211 Chestnut St., Chevy Chase, MD 20015 GMT, QSLed

         8-1: 1610, KIF 355   37.26  McMinnville, TN (100 watts)
        9-16: 0008, N984MA   119.7   ov Chesapeake Bay Bridge (John J. McDon-
                                     nell; Piper Navajo PA-31; 2-eng.,6-seat)
       12-16: 1612, N734N    132.5   ov Phil., PA (Piedmont; Boeing 737; 25 w)
        1-13: 1939, CF-QBO   134     90 mi north of Norfolk, VA (Quebecair;
                                     BAC 1-11; 60 watts)
      ------------------------------------------------------------------------
       Now, my loggings. Allied A-2586 with 30-ft indoor random-wire antenna,
       50-MHz with Swan 250 and 3-element CushCraft horizontal Yagi at 14 ft;
       all are F2 (* backscatter) unless noted; peak unID daily F2 noted if
       40-MHz or more; Sp.-Spanish, rtty-radio teletype, Col.-Colombia, sol.
       noise - solar noise matching Boulder bulletin; CST, new underlined

       3-11: 1332, sol.noise      30: 1035, KAI 927 (Es) 6: 1400, 46.7-Sp.
         12: 1152, sol.noise          1049, KDN 407 (Es)    1833, KMA 829 *
             1214, sol.noise          1230, 45.1-Sp.     8: 1250, 46.9-Sp.
         15: 1224, sol.noise      31: 1659, KLF 527         2320, KDN 407 (Es)
         17: 1722, KMA 829 *     4-1: 1320, sol.noise    9: 1132, sol.noise
         19: 1305, 46.9-Sp.           1500, 50.075          1322, sol.noise
         21: 1340, 42.5-Sp.           1655, WB5AHC *        1325, 45.1-Col.
         24: 1425, 45.1-Sp.        2: 1300, 45.3-Sp.        1405, 47.3-Sp.
         29: 1410, KFL 943 (Es)       1616, KLF 527         1535, 44.7-Col.
             1650, L Beach (Es)    3: 0920, KDN 402 (Es)10: 1311, sol.noise
             1959, S Diego (Es)       1335, 46.1-rtty       1635, KLF 527
             2104, KMA 829 (Es)    4: 1425, 46.7-Sp.        1729, KMA 829 (Es)
             2110, KDG 872 (Es)    5: 1345, 46.3-Sp.    11: 1340, 45.1-Sp.
      -------------------------------------------------------------------------
       KAI 927  35.34  Denver, CO            KLF 527  35.22  Honolulu, HI
       KDG 872  33 +   Los Angeles, CA-f     KMA 829  35.58  San Diego, CA
       KDN 402  35.54  Omaha, NE             WB5AHC   50.12  Irving, TX-a
       KDN 407  35.22  Co Springs, CO           -     35.58  Long Beach, CA
       KFL 943  35.58  Las Vegas, NM            -     35.46  San Diego, CA-mp

       a-amateur, f-fire, mp-mobile phone; rest are pagers with A2 tone Morse
       ID from KAI 927, KDN 402, KDN 407, and KMA 829.
      -------------------------------------------------------------------------
       The following table is a condensed version of previously run ones (this
       column in Aug 1970 and July 1971 and 1972) and gives the M-factor for a
       non-tilted Es patch at 105 km using the 'secant law'.

       1400: 1.000       1000: 1.062       600:  1.380      200: 3.087
       1300: 1.004        900: 1.105       500:  1.566      150: 3.681
       1200: 1.015        800: 1.166       400:  1.849      100: 4.423
       1100: 1.033        700: 1.254       300:  2.304       50: 5.207

       To use this, suppose you have 40-MHz skip down to 600 miles, then the
       1420-mile skip (the maximum for the given height) should be 40 x 1.38 =
       55.2 MHz. Recall that the Es must be near the path midpoint, so getting
       short skip in the 30-50 MHz range will not always give you TV skip.

       By plotting the above on graph paper, intermediate distances can be
       interpolated for. This can also be used to determine minimum skip range
       for frequencies below the MUF. Additional explanations and data for
       those interested are available for an s.a.s.e.
       ------------------------------------------------------------------------
       The Es season should be well under way when this appears. Again, it is
       desired that some DXers with 108-118 MHz rcvrs check for VOR's when the
       MUF is up above FM. The slow A2 Morse ID's are continuously sent.

                                                  73,    WA5IYX