[Amps] Where is power measured ?

[Mike McCarthy, W1NR]

On 04/06/2011 08:38 AM, Roger D Johnson wrote:
> On 4/6/2011 8:11 AM, Jim Thomson wrote:
>> Someone mentioned that in the US, the power is measured at the back of the amp.
>> Your rules don't stipulate where it's actually measured.  Dave Leeson, and other's,
>> contacted FCC officials, and the FCC said it was reasonable to measure the power at the
>> load, IE: ant feed-point.  US broadcast TX are measured at the feed-point, or close to it, not the
>> output of the amp at base of tower.
>>
> FCC rules 97.313
>
> (b) No station may transmit with a transmitter power exceeding 1.5 kW PEP
>
> 73, Roger
>
>

Broadcast stations power in many cases, especially digital TV, by ERP
rather than TX power.

I knew a QRP'er who had 5 watt amps at the antenna feedpoints to
maximize ERP and eliminate feedline loss.

Mike, W1NR