I've finished my second U3s.
Again in the sturdy professional BOPLA ULTRAMAS case. The DC voltage regulators are simply LM317 based ones.
The PA in this U3s is running with 9VD and features the bifilar output transformer in the PA. In this U3s I've added two PA FETs which results in this output:
Band | Power | Power |
10m | 24dBm | 251mW |
15m | 25dBm | 316mW |
20m | 24dBm | 251mW |
30m | 25dBm | 316mW |
40m | 26dBm | 398mW |
60m | 29dBm | 794mW |
80m | 30dBm | 1000mW |
I assume the low power on the upper bands is due to the gate capacity of the BS170 FET.