[Elecraft] dBi dBd correction

[Augie Hansen]

Guy, K2AV wrote:
> The way the regulation reads, hams are being told they can put 50 watts PEP
> on an antenna, up to the gain of a dipole, and call that 50 watts ERP. 
> Higher gain must be referenced to the dipole and the 50 watts reduced
> accordingly. 
>
> For mobile stations there is no mention of the idea that a LESSER antenna
> may have the 50 watts increased. 100 watts appears to be in excess of
> regulation.  Stated another way, 50 watts max regardless, unless the antenna
> has more gain than a dipole in which case power must be reduced by a factor
> representing the gain of that antenna over a dipole.
>   

Where did you get that interpretation? The ARRL Q&A, based on the FCC 
rules, says the following:

<quote>
The "best" antenna configurations are those with a proven track record 
on the lower bands, keeping in mind that using a loop or an array of 
some kind will require you to "do the math" to ensure you are not 
radiating more than 50 W ERP /in any direction/. The math is fairly 
straightforward. You must reduce your power by the number of decibels 
your antenna gain exceeds 0 dBd (0 dB relative to a half-wave dipole). 
Conversely, you can increase your transmitter power if your antenna 
exhibits loss compared to a dipole. Be prepared to document these 
situations in your station records, however.
<endquote>

Gus Hansen
KB0YH