Do you not have a SWR meter? If it's popping transistors then it must be no good, or you have a bad connection. I can't answer your question, however. I know a roof can help bounce more of the signal in a horizontal direction which can help, but height is more important when it comes to VHF.
For simplicity and ease of installation I just use dipoles. I know the gain is not as good as a 5/8 wave but they are simple to tack on to any mast and the SWR never changes.
Regards,
Ross.
----- Original Message -----From: M.B & J.D DuffyTo: LPFM_Radio@...Sent: Saturday, October 02, 2004 10:32 AMSubject: [LPFM] AerialsHi just to change the subject a technical ?
I know that higher = better but is there a maximum above the mounting point
that a 5/8 wave aerial will work?
I ask because I have been experimenting with raising my aerial on a pole.
When it is placed on it's usual hockey stick appox 4' above a metal roof all
is fine.
If I raise it to about 20' it will go fine, get a bit better range but
enevtably pop goes another difficult to get 2sc1947
Same tx, coax just different heights.
Does the aerial need the metal roof for grounding?
Any thoughts?
Maurice
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