DEI Transistors

[bevis]

View attachment 46527

aluminum foil is good for 250-ish. Here's the redneck fuse guide.....

View attachment 46530

LMFAO
Priceless and TRUTH

 

[TRASHYTRAM]

Amp now holds steady at 650 watts of PEP @ 42 Amp draw. Power idles at 14.2 volts and pulls down to 14.0 volts under modulation.

42 X 14 =588 so your watt meter may be a bit loose.

 

[144inBama]

Some useful info here......

https://www.arworld.us/PDFs/appNotes/AppNote49.pdf

and here:

http://faculty.sdmiramar.edu/faculty/sdccd/wnorth/109c/AMT109Cfive.pdf

 

[Greg T]

42 X 14 =588 so your watt meter may be a bit loose.

Two meters show the same and the one I use is the Daiwa, which is tighter than my MFJ. In any case, the power wire upgrade made a huge difference.

 

[144inBama]

Here's where ohms law fails me in RF.... If you use Ohm's Law with 14.7VDC and say 65A, it gives you .226 ohms and 955.5 watts.... Where does the 50 ohm load (coax) come into play for the calculation? The entire transmission length has a 50 ohm load yet you cannot figure that into the equation.

 

[Shockwave]

Here's where ohms law fails me in RF.... If you use Ohm's Law with 14.7VDC and say 65A, it gives you .226 ohms and 955.5 watts.... Where does the 50 ohm load (coax) come into play for the calculation? The entire transmission length has a 50 ohm load yet you cannot figure that into the equation.

The amplifier is converting DC input to RF output. The .226 ohm input resistance is what it takes to draw close to a thousand Watts from the DC line. To produce a similar output power into 50 ohms, means the RF voltage is much higher than the DC voltage. Someplace over 200 volts of RF. With approximately 200 volts of RF applied to a 50-ohm antenna system, we are delivering 800 watts of RF to that antenna.