Hi
    You will need to subtract the DB loss of the feed line from your radio 
to the antenna before multiplying it by the gain of the antenna.  You can 
also subtract your feed line loss from the antenna gain and then use the 
resulting number  to calculate the ERP.

                    God bless,
                    Mark WZ0K
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----- Original Message ----- 
From: "Colin McDonald" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, March 08, 2006 9:45 PM
Subject: Re: thinking of changing rigs


> if you want to know your true input power, that is, the power being input 
> to
> the final transistors, it won't be what you are actually transmitting.
> Remember, the concept of input/output went out of style with the use of
> transistorized radios.
> However, a more common measurement now is input power into the antenna,
> which is actually the radios output power, say 100 Watts, and the ERP, the
> measurement of your power multiplied by the DB gain of the antenna.
> 73
> Colin, V A6BKX
> ----- Original Message ----- 
> From: "Ed Malmgren" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, March 08, 2006 6:17 PM
> Subject: Re: thinking of changing rigs
>
>
>> Are you sure that is input power, I haven't heard anything for  years
> about
>> input power.  That was the way of measurements in years gone by   Ed K7UC
>>
>