[Lowfer] " XR's " first WSPR weekend

[John Andrews]

Andy,

> *** How ever accurate the power test may be; the meter shows
> 1-1/2 watts output into the 50 Ohm dummy load MAX, and distorted,
> using a 1500 cycle tone. For a clean output, it shows .75 watts .

That's 17 volts peak to peak across 50 Ohms. That's more than enough to 
drive any 1 watt Class D. PA. Did you have a 50 Ohm termination at the 
input of the PA? Is there a schematic of the PA available?

> I can connect the radio directly to the 50 Ohm LPF, and see
> 60 mW of RF current on the RF ammeter running wide open........
> I connected the radio output thru a .33µF cap to the input of the
> Class " D " amp, and got 90 mW of RF thru it.. Disappointment !!

Are you doing a calculation to get those mW readings from the antenna 
ammeter, or are you talking about the antenna current in mA?

John, W1TAG