My XV50, fed by my K2 through an XV60 transverter adapter always
emits 20 watts of power regardless of the power setting on the front
panel of the K2.
The XV60 ALC circuitry seems to be working. I've measured pin 6 of J13
on the XV60 using various power control settings and I get the
expected results.
At 1.00 LP, pin 6 measures 3.51V, the K2 LCD reads 0.94 and the watt
meter reads 22 watts.
At 0.50 LP, pin 6 reads 2.50V, the K2 LCD reads 0.48 and the watt
meter reads 21 watts.
At 0.10 LP, pin 6 reads 1.54V, the K2 LCD reads 0.10 and the watt
meter reads 21 watts.
I can't measure at K2's R66 as the KNB2 is in the way but I did do a
continuity check between pin 6 of J13 and R66 and had a good
connection.
I tried adjusting the RF power level with R22 on the XV50 and had good
results. R22 controls the output power fine. Using R22, I dropped the
maximum XV50 power out to 10 watts and rechecked the voltages at pin 6
of J13. They remained the same as listed above with the exception of
the watt meter which consistently read 10 watts out instead of ~20.
So now I'm stumped. The XV60 ALC is correctly reading and responding
to the TXRF on the XV60. There is nothing between the XV60 TXRF and
R22 on the XV50 and R22 provides a bias to Q6 which, in turn, controls
the output level.
I've checked all the components on the XV60 ALC circuit and all those
associated with the Q6 level control circuitry; I've also checked and
double checked the all the jumpers for the XV60 low power installation
and they are correct.
The XV50 both transmits and receives on frequency, so the basic
circuitry seems to be OK.
Either Q6 is bad or I'm missing something (probably the latter).
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