10W HF Linear PA kit assembly
1.00
34
The next image shows the same thing but the vertical scale is expanded to 2dB/division:
2) Operation at full power into open output, shorted output, 20-foot long open cable, open
cable with short
– all with no oscillation or damage
3) Amplifier is still capable of 10W at 50MHz (6m band) though gain is down by 4dB compared
to HF
4) Gain is 8dB down at 70MHz (4m band) compared to HF
5) With sufficient drive, the amplifier is capable of producing 20W output at 13.8V supply using
+15dBm input, over the range 3-30MHz
6) Operated with +20V supply
7) At 10V supply still over 7W output
8) A clean 3.5MHz (80m band) source running at 10W output had 2
nd
harmonic at -38dBc and
3
rd
harmonic at -31dBc
– very good linearity
9) Operated at full-power continuous key-down, 100% duty-cycle for 1 hour, without damage
or degradation in performance.
