Luc,
Before offering any specifics, can you make some RF Voltage measurements
during a TUNE operation please? With that information, the problem can
be isolated to one stage.
Measure the following points for both 40 meters and 20 meters:
Q1 gate
Q1 Source
Q4 base
Q5 base
Q5 collector
Q6 base
Q6 collector
Please also tell us whether the voltages are peak to peak, zero to peak
or RMS values.
73,
Don W3FPR
luc Favre wrote:
Hi all,
I got a problem building my KX1: receive is OK, but transmit power is far
too low (40 m < 2W, 20 m <0,5 W with 13,5 V).
Of course, I checked and double checked solders, solder bridges, components
and values. BPF and LPF are OK as measured with RF generator and
oscilloscope. Output waveform good. Frequency right.
Transmit voltages are all OK, but Q7's transmit base voltage is minus 1,1 V
(minus) instead of the requested plus 0,7 V. Resistances and other
components Q7 circuit are OK? 6V_2T is + 5,5 V. Q7 replaced Q7 without.
Any idea will be welcome !
73
Luc/HB9ABB/F6HJO
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