Re: 0.03w RF output, 1w at transistor drains, Help


Jim Painter
 

Jim, good information. Thanks...

Jim...kq3s


On Wed, Aug 19, 2020 at 8:50 AM, James Daldry W4JED
<jim@...> wrote:

PUH-LEEZE!!

When applied to a point with a DC voltage, the "wattmeter" reads the DC as "watts". Any DC voltage above a certain level (Hans could probably tell you what that level is) is read as 5.2 "watts". Meaning, any "watt" readings on the drains of Q1,2,3 are meaningless. It only tells you that the DC is getting there. If you were to touch the 12 volt input connection it would read 5.2 "watts". Look at the schematic. There is no blocking capacitor to keep the DC out of the A to D converter. Before C29, MEANINGLESS. After C29, sorta OK. At the antenna jack (where there is an actual sine wave) something like an actual reading, provided it is connected to a 50 ohm dummy load. Not an antenna, because the impedance of an antenna can be all over the place, and the reading will change with impedance.

73

Jim W4JED

On 8/18/20 8:57 PM, spam via groups.io wrote:
I'm measuring '5.2w' on the input of c29, and only 0.14w on the other side, I'm assuming this is not correct here

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