[TenTec] power output of ten tec delta

[Steve Berg]

As a living fossil I can weigh in on this one.  Until the advent of the 
Bird wattmeters, which none of us youngsters could afford, there was no 
common way to measure output power of transmitters.  Input power to the 
final stage could be determined with a Simpson 260, a cheap imported VOM 
or a couple of surplus meters. That, we could afford.  My first HF 
transmitter was a Knight T60 which did not even meter power input.  We 
just hoped it was the advertised 60 watts, and peaked up the relative 
output power meter on the front panel.  Now we is much more 
sophisticated and debonair and the price of reading RF power is 
relatively much lower.  Even the FCC responds to improvements in 
technology.

Steve WA9JML

Ken Brown wrote:
>> this was a regulatory issue. Until sometime in the 1980's the 
>> FCC specified that the DC Power Input to the Final Amplifier stage was 
>> the Power of record. In other words, the actual output power was never 
>> considered for purposes of testing a station's compliance with the 
>> rules.
> In the days of link coupled outputs and open wire feeders, rather than 
> standard impedance coaxial cables, it was easier to measure it this way. 
> Another detail was that you could run up to 900 watts input without full 
> metering, and above 900 watts you were required to have both the plate 
> voltage and current metered.
>>  
>> The ones who lost out on this rule change were the AM operators. They 
>> had been allowed to run 1000 Watts DC input power, netting perhaps 500 
>> Watts out. 
> Only the final PA input power was included, not the modulator power. 
> With a push-pull class C final RF PA and 1000 watts DC input you could 
> perhaps have 75% efficiency, resulting in 750 watts of unmodulated 
> carrier output, and at 100% modulation that could be 3000 watts output 
> on the modulation peaks.
>> was to be measured as the Actual Output Power, they set the maximum 
>> Amateur Output Power as 1500 Watts PEP. This meant that the AM operators 
>> had to Reduce their Carrier Power to 250 Watts to comply with the new rule.
>>   
> I think you can have a 100% modulated 375 watt carrier and just hit 1500 
> watt peaks.
> 
> With some many OTs accustomed to the final PA input power as the way to 
> express a rigs power rating, what company would want to start using the 
> output power in their advertising when it is only half as impressive.
> 
> DE N6KB
> 
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