I just did some quick modeling on Eznec using a 6m 30' boom yagi model I
Case 1: Only mast (tower) 45' tall, 4" dia over perfect ground, 3.65MHz
Source impedance 13.3 - 146j ohms, SWR (50ohms) 36
Case 2: Mast with a 30' boom 6m yagi just above it, NOT touching
source impedance14 - 137j ohms, SWR 31
Max current in boom 0.03A (for 1A feed feed current)
Case 3: Boom connected to mast, not insulated
source impedance 30 + 5j ohms, SWR 1.7
Max current in boom 0.3A (for 1A feed feed current)
My bottom line - No connection - No good. There is some effect if the
antenna is insulated but not much.
Perhaps you could put in a relay to short the boom to tower/mast when
----- Original Message -----
Sent: Friday, June 07, 2002 2:57 PM
Subject: [Towertalk] is an LP a good sloper top hat?
> I have a tower mounted half-sloper, with an log periodic
> on top of the tower. Problem is, the log is completely
> insulated from the mast on the tower. Does it still work
> as a top hat to the tower for the sloper to work against?
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