[rescue] OT: Linux and USB on Intel

Dave McGuire mcguire at neurotica.com
Mon Apr 21 13:22:52 CDT 2003

On Monday, April 21, 2003, at 01:56 PM, Kevin Loch wrote:
> According to FCC rules part 97:
> http://www.arrl.org/FandES/field/regulations/news/part97/
> Output power on most bands is limited to 1500W PEP (peak envelope 
> power) output from the transmitter.  "Peak Envelope Power" is a 
> function
> of the voltage output of the transmitter and the impedance
> of the antenna system.  Therefore the power output of the transmitter
> is limited, but not antenna gain.  In no case is there a
> limit of power into the 'final stage' of the transmisster.

   It's certainly possible that I'm misremembering this, but I'm pretty 
sure about it.  I have an FCC rule book here; I will look it up this 
afternoon to see where I've gone wrong.

   But for now, a quick google turned up this:

 > Under the old rules the limit was 1,000 watts input to the final 
amplifying stage for CW. > Well, if you tuned up on the air, which 
nobody ever did, the theory was that you
 > calculated the power input from B+ voltage and total of grid and 
plate current. At 65%
 > efficiency you could legally pump 650 glorious hot watts into your 
antenna. Halleluiah!
 > But, for phone I believe the limit was 2,000 watts peak envelope 
power (PEP) input to
 > the final amplifying stage. God help me if I make an error here.
 > Big Brother was lobbied by somebody, or they blinked or caved and 
legal limit was reset
 > the to 1,500 watts output, CW or PEP, at the amplifier output 
connector. Halleluiah!
 > Another but, isn't there a correlation between the power of these 
wonderful amplifiers
 > and gravity? Let's see - 650 watts to maybe 1,500+ watts. I dough no, 
twice, thrice the
 > weight?  They used to make some of em in two pieces, with separate HV 
power supply on the
 > floor and RF deck on the table. Hell - they're twice, thrice as heavy 
now and they put
 > every thing in one big box and I can't pick the son-of-a-bitch up.

   ...which suggested that those rules have indeed been changed, so 
ignore what I said earlier, and I apologize if I misled anyone.  This 
was found at:


> Such a limit would have no effect since any ammount of
> gain could be applied in the 'final stage'.

   Not true...the output power of an amplifier cannot exceed the power 
fed into the amplifier.  I'm talking the *power supply* here, not the 
RF drive.  If you have, say a 2.5kV plate supply capable of supplying 
100mA of current, you won't see more than 250W of power out of that 


Dave McGuire           "She's a cheek pincher.  I have scars."
St. Petersburg, FL                          -Gary Nichols

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