Note: groups.io will be down for maintenance on Monday, September 26th, starting at 9AM Pacific Time (4PM Monday September 26, 2022 UTC), for approximately one hour.
- 0.03w RF output, 1w at transistor drains, Help
Re: 0.03w RF output, 1w at transistor drains, Help
toggle quoted messageShow quoted text
Jim, good information. Thanks...
On Wed, Aug 19, 2020 at 8:50 AM, James Daldry W4JED
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.
On 8/18/20 8:57 PM, spam via groups.io
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
Join QRPLabs@groups.io to automatically receive all group messages.