Re: 80 Meter 50 Watt PA


Shirley Dulcey KE1L
 

Also, the output power is rated at 20V input. Your laptop power supply is rated at 19V, and it may not deliver that full voltage under what is likely to be a near-maximum load for it. Check the actual voltage being delivered to the 50W PA; if it's well under 20V, the output power is going to be less than 50W.


On Mon, Jul 6, 2020 at 1:09 PM Ronald Taylor <wa7gil@...> wrote:
Ralf, speaking only from my own experience, I did the same thing. I actually built a multi-band version with switched lowpass filters and got similar results on 80. I noticed the amplifier performed best on 40 meters with a slight decline on 80. Remember it was designed for optimal performance on 40, 30 and 20 meters. But 40 watts on 80 will certainly perform very well. And it's only 1 dB down from 50 watts. I would say enjoy it as is... 73 ... Ron

On Mon, Jul 6, 2020 at 9:38 AM Ralf Rosche <ralf.rosche@...> wrote:
Hi all,
i am using my 80m 50w PA since some time now. 
I took 50-2 toroids and 470pf and 1200pf silver mica caps.
I tested the low pass with my nano VNA and it works perfect as expected.
Bias adjustment was no problem. Works good out of the box :-)

Regarding the output power, what do you achive?
I took a 19V Notebook power supply and getting about 40watts with 3350mA current drain.
It peeks at 45w at keydown and goes back to 40w.

My QCX is powered with 12V and has 3w rf output.

Is 40w usual or should I optimize my PA?

Ralf

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