On 4/2/2011 6:21 PM, Don Jones wrote:
Power dB = 10LOG*(P1/P2).
That's fine formula for gain and loss based on power ratios, but not a
great benefit in figuring power to a dummy load with a voltmeter. And
what you use as a indicator for the dummy load affects the way you
compute power. For DC its P = E * E / R. For a half wave peak reading
meter (and pure sinewave) its P = 0.5 * Ep * Ep / R. For a peak to
reading like get on the oscilloscope its E = Epp / 2.828427 where
2.828427 is the square root of 8.00000, then apply P = E * E / R. Or P =
Epp * Epp / ( 8 * R)
73, Jerry, K0CQ
Question #1, do you have a calibrated volt meter? Might be useful to check your
input voltage.
Question #2, is your "50 ohm load" calibrated?
Question #3, I am not familiar with the Motorola Comm Analyzer... Is it rated
for HF freq's? It is my impression that the Motorola stuff is mostly VHF/UHF
rated equipment.
Good question on its frequency rating.
Go back to the post from 9JML about his experiences comparing final
tuning test bench results with QC at a Motorola factory building two way
radios. He fought differences with "calibrated" equipment all the time.
Peace,
Don Jones ko7i
Arlington, WA
-----Original Message-----
From: Mike Bryce [mailto:prosolar@sssnet.com]
Sent: Friday, April 01, 2011 6:37 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] eagle
I have access to a very expensive motorla comm analyzer. $50k, calibrated to
traceable standards.
My personal coaxial dynamic watt meter and if course a 50 ohm dummy load.
So, I am not using an old radio shack CB watt meter, but calibrated RF test
equipment.
Mike
Sent from my iPhone
|