[TenTec] eagle

[Dr. Gerald N. Johnson]

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 at 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
>
>