Using an isolator between a 100-watt transmitter and a perfectly matched antenna still only gets you 90 watts out. A typical isolator loses 0.5 dB on the forward path.
73, Paul, AE4KR ----- Original Message ----- From: Gary Schafer To: [email protected] Sent: Thursday, June 05, 2008 11:06 AM Subject: RE: [Repeater-Builder] Re: Folded Diploles or Vertical antenna/Power Readings This is not entirely true. A transmitter with an isolator on it will absorb all the reflected power that reaches it. There will be no re-reflected power back up to the antenna. In this case reflected power does subtract from the power that is available to be radiated by the antenna. 100 watts out of the transmitter, 10 watts reflected, leaves 90 watts that reach the antenna to be radiated. Improve the match at the antenna so there is no reflected power and you have a full 100 watts to be radiated. 73 Gary K4FMX > -----Original Message----- > From: [email protected] [mailto:Repeater- > [EMAIL PROTECTED] On Behalf Of Laryn Lohman > Sent: Wednesday, June 04, 2008 7:36 PM > To: [email protected] > Subject: [Repeater-Builder] Re: Folded Diploles or Vertical antenna/Power > Readings > > --- In [email protected], Wayne <[EMAIL PROTECTED]> wrote: > > > Note that forward power can sometimes read higher than true if > there is > > more reflected power. > > > Very true. Power coming back down the line is RE-reflected in the > transmitter and adds to the forward power, producing an *awesome* > forward power reading. > > > > And to answer something that one person came up with a while back, > > decreasing the reflected power does not add it to the true radiated > power. > > > ...Another way of saying that reflected power does NOT subtract > directly from the power that is radiated by the antenna. > > >
