09-09-2017, 07:26 PM
Ah! I thought the masthead amp was for the log!
Being so close to the transmitter, have you tried the aerial without the amp in case it is being overloaded? You might be benefiting from refraction over that high ground. Also, your aerial could be higher AGL than the 10m default.
The closest I could emulate your signal profile is this:
![[Image: chart?chs=680x227&chma=30,8,20,25&cht=lc...0,31,63,95]](http://chart.apis.google.com/chart?chs=680x227&chma=30,8,20,25&cht=lc&chd=e:-jCE,-j.y.y.l.l.L-9-j-W979u9H858S8E7d616o6A5m4-4x4J3v3H2t2F1r1D0c0Bzay.yKx9xIwuwGvsu3uqt1taslr-rjqvqUpfpFoQn2nOm0l.lkkvj7jgiriEhPg0gAfleweWdUc5cEbqaoZzZZYXX8XHWgVrVDUOTnSySKRIQGPsOqOCNAMYLWKvJfI4HoHBFkEvCE,-j-9-w-W-J9u9h858f737q7C6o6A5z4-4X4J3V3H2S2F1Q020Oz0zMyyx9xVw7wGv5vEuqt1toszsYrjrJqhqHpSodoDnbnBmMlxk9kijtjTieiEhPgagAfLewd7dhcscSbdbCaOZzY-YkXvW6WSVeVDUOT0SySXRjRIQGPsO3N1NaMYL-K8KhJfI4IDHbGZFxEiD7CE,-j8s8E616O5L4k3i3H2F1r0p0OzMyyxww7whvevEuPt1szsYrjrJqHpto4oDnom0mZlklKkVjti4iehphPgagAfLejeJdUc5cEbqa1abZmZLYXYJXVWgWFVQVDUOT0S.SlR9RjQuQhPsPROqN1NaMzMYLxLWKhKUJfJSIdIQHbG0GmFxFkE9EiD7DtDGC4CeCEB2BpCE,-j737C5m4-3v3H141Q0Oznylx9w7whveuct1tAsYrWq8qHpfoqoQnOm0lxk9kijtjGiRh2hCgnfyfYeWd7dHcsb3bCaoZzZZYkYXXiXHWSV4VDUpUBTMSyR9RwQ7QhP5PeOqOcNoNNMlMLLjK8KhJ6JfI4IdH2HoG0GmF.FxFKEiEVDtDgC4CrCRCEBpBcBCBCA0A0CE,oDoDlkkVh2ejYxVrQuOcNaLxMlQhRjRIQGN1L-J6I4G0E9G0JSMzOqU2WtVrW6X8XiXHV4VQU2TMSyR9RIQuPsOPOCMzMlLjMLMlMYK8LWL-MlMlLxLJIQF.GMJSKhLJK8KHJtJfKUK8KHIDHOF.FxFkGZH2HoGZFkFkFKF.G0KHJ6IqHoHoHoGME9DTBPCrDgBPAnAN,nBnBkijTg0dhXvUpQuOcNaLxMlPeQhQGPEMzL-J6I4GmE9G0JSMzOqT0VrUpV4W6WgWFVrVDUpS.SlRwQ7QhPeOCN1MlMYLWL-MYMLKvLJLxMYMYLjK8IDFxF.JFKUK8KvKHJtJfKUK8KHIDHOFxFkFkGZH2HoGZFkFkFKF.G0KHJtIdHbHbHbF.EvDGBCCeDTBCAaAA,AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA,AAAA&chf=bg,s,CCCCCC|c,lg,90,336699,1,6699CC,0&chco=000000,FF6600,FF3300,FF3300,FF6600,663300,009900,000000,000000&chm=b,FF6600,1,2,0|b,FF3300,2,3,0|b,FF6600,3,4,0|b,663300,5,6,0|b,009900,6,7,0|b,000000,7,8,0&chxt=x,y,t&chxs=0,000000,10,0,lt,000000,000000|1,000000,10,1,lt,000000,000000|2,000000,10,0,lt,000000,000000&chxtc=0,6|1,6|2,6&chxr=0,0,8.73,1.0|2,0,14.04,2.0&chxl=0:|mi|1:|m|100|200|300|2:|km&chxp=1,0,31,63,95)
But raising the aerial gives this improvement:
![[Image: chart?chs=680x227&chma=30,8,20,25&cht=lc...0,31,63,95]](http://chart.apis.google.com/chart?chs=680x227&chma=30,8,20,25&cht=lc&chd=e:-jDG,-j.y.y.l.l.L.L-w-j979u9U9H8f8S7q7C616O5z5L4-4X383V3H2S2F1Q0p0cznzMylyKxjxIwhwGvRvEuPt1tAsYr-rJqvqHpto4odnonOmZl.lKkikIjTi4h2hcgngNfYe9eJducscSbdaoaOZLYxXvXVWgV4VDUcTnS.SKRIQhPePEN1NaMLLxKhJ6IqIDGmFxDG,-j-9-w-j-W9u9h858s8E7q7Q616O5z5L4k4J3i3V2g2S1e1Q0c0Bzay.yXxjxIwhwGvevEuPt1tNszr-rjq8qhptpFoqn2nbmmmMlklKkVj7jGirh2hCgnfyfleweWdhdHcSb3bCaoZmZLYXXiXHWSV4VDUpTnTMSXR9Q7QhPsOqOPNaMzL-LWKhJ6I4IdHOG0FkE9DG,-j8s8E616O5L4x3v3H2S1r020Ozay.x9xIwhvsvRucuCtAslrxrWqhqHpSoQn2nBmmlxlXkikIjTi4iEhpg0gnfye9ejdudUcfcEbdbCaOZzY-YkX8XHWtV4VrU2UcTnTaSlSKRjRIQTQGPROqOPNaNNMYMLLWLJKUKHJSJFIdH2HbG0GZFxFkE9EvEID7DTDGCrCrDG,-j737C5m4-3v3H141e0OznylyKxIwhveuquCtAslrxrJqUpto4odnbnBmMlXkvj7jgiriRhchCgAfleweWdhdHcSbqbQabaAZLYxX8XiW6WgVrVQUcT0TaSlSXRjRIQhQGPePEOPOCNNNAMLLjLWKhKUJtJSIqIQH2HbG0GmF.FXFKEiEVD7DgDGC4CeCRCEB2B2B2DG,oDoDlkkVh2ejYxVrQuOcNaLxMlQhRjRIQGN1L-J6I4G0E9G0JSMzOqU2WtVrW6X8XiXHV4VQU2TMSyR9RIQuPsOPOCMzMlLjMLMlMYK8LWL-MlMlLxLJIQF.GMJSKhLJK8KHJtJfKUK8KHIDHOF.FxFkGZH2HoGZFkFkFKF.G0KHJ6IqHoHoHoGME9DTBPCrDgBPAnAN,nBnBkijTg0dhXvUpQuOcNaLxMlPeQhQGPEMzL-J6I4GmE9G0JSMzOqT0VrUpV4W6WgWFVrVDUpS.SlRwQ7QhPeOCN1MlMYLWL-MYMLKvLJLxMYMYLjK8IDFxF.JFKUK8KvKHJtJfKUK8KHIDHOFxFkFkGZH2HoGZFkFkFKF.G0KHJtIdHbHbHbF.EvDGBCCeDTBCAaAA,AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA,AAAA&chf=bg,s,CCCCCC|c,lg,90,336699,1,6699CC,0&chco=000000,FF6600,FF3300,FF3300,FF6600,663300,009900,000000,000000&chm=b,FF6600,1,2,0|b,FF3300,2,3,0|b,FF6600,3,4,0|b,663300,5,6,0|b,009900,6,7,0|b,000000,7,8,0&chxt=x,y,t&chxs=0,000000,10,0,lt,000000,000000|1,000000,10,1,lt,000000,000000|2,000000,10,0,lt,000000,000000&chxtc=0,6|1,6|2,6&chxr=0,0,8.73,1.0|2,0,14.04,2.0&chxl=0:|mi|1:|m|100|200|300|2:|km&chxp=1,0,31,63,95)
So it might not be as bad as you think.
As for the switch, I would expect it to terminate the unused feed in 75 ohms but the selected feed to be connected straight through, as you have found.
Being so close to the transmitter, have you tried the aerial without the amp in case it is being overloaded? You might be benefiting from refraction over that high ground. Also, your aerial could be higher AGL than the 10m default.
The closest I could emulate your signal profile is this:
But raising the aerial gives this improvement:
So it might not be as bad as you think.
As for the switch, I would expect it to terminate the unused feed in 75 ohms but the selected feed to be connected straight through, as you have found.
