[Elecraft] K60XV no tx power problem

[Don Wilhelm]

Stephen,

 From the behavior you indicate, I would believe you have something 
wrong with the VRFDET signal.
Check first by removing the K60XV - install a low value capacitor (4.7 
pf is ideal) between the output two pins of J15 and install a wire 
jumper between pins 3 and 5 of J13.
With those 'unmodule' connections, see if you have proper operation on 
all bands (60 meters will not work, of course).   If operation is not 
restored, check the wires added to the bottom of the RF board carefully 
against the manual instructions, and be certain there are no solder 
bridges at J13.

If proper operation is restored with the temporary jumpers, then look at 
the soldering on the K60XV board, particularly at P1.

My best guess is:  If you have an older K2 (SN less than 3000), you did 
not make an adequate cut on the trace to J13 pin 6, or if you have a 
post SN 3000 K2, there is a solder bridge from the '8T' point near J13 
pin 6 to the 'X' point near it.

The reason for this guess goes to the heart of the K2 power control 
mechanism.  If the 8T line is connected to the VRFDET signal line, the 
K2 microprocessor thinks it is putting out a lot of power and reduces 
the BFO injection to attempt to reduce the power to the requested 
level.  The result would be an indication of high power out (19.1 watts) 
due to the voltage on the VRFDET line but no actual power output since 
the microprocessor has reduced the BFO injection to as low as it can 
possibly be reduced.

73,
Don W3FPR

Stephen Prior wrote:
> I have just spent the afternoon here putting the K60XV board in my K2 s/no.
> 4930.  It works fine on rx and tests out okay until I get to the part on
> page 13 where I have to set to 2W and peak C1 and C2 on the 60 metre board.
>
> I have no power output, nothing registered on a 5W fsd external meter and
> full scale deflection on the K2's meter with 19.1 Watts shown irrespective
> of the position of the power control.  The same behaviour is seen on every
> other band.  Yet the rx works fine on all bands.  At this point I have the
> K2 bare except for ssb and noise blanker modules, and of course the K60XV -
> the KAT2 and KIO2 are still sitting in the top lid on the floor beside me.
>
>