开云体育

I built my first 30m beacon and it worked first time, but I have not been able to get the power out up to 100mW (20dBm). I only get about 54mW (17dBm) into a 50 ohm load. I measured this several ways and verified it.

So I built my second kit and I get he very same results. I think this verifies that I didn't make an error on the first one. I have verified the output filter with ELSIE and it agrees very well. The apparent problem is excessive loss in the LP filter, but I don't think that that is the case.

73,

Cash KD5SSJ

Hi,
Verify the total DC Current. I remember about 85-90 mA from my unit when set at 100 mW output when it was in FSK CW mode (now CW).
Is your RF cable OK and correct impedance (75 ohms can throw a curved ball if you are not careful)

Check DC volts on stages etc/ Mine is run on 5V.

On another topic
When I modified my 30m TX to CW as on the Hans Summers site. the CW back wave was only 13 dB down and added a 56 pF to ground from FET gate which improved it down to 33 dB or so. (Other bands might require experimenting.Drive RF was driving the FET into Class C.

Kevin
ZL1UJG