[Elecraft] K2: first snag...

Don Wilhelm w3fpr at earthlink.net
Fri Jun 8 16:01:29 EDT 2007


Mike,

OK, if you have checked the stuff in the troubleshooting area, it is 
time to make some in-depth measurements to determine what is working 
properly and what is not.

First thing to do is to look very carefully at your soldering - that is 
the most likely cause of failure.

Second is the verify that all components in the left front area of the 
RF board have the correct values.  Also be certain ICs, diodes, 
varactors, and transistors are inserted the 'right way around'.  Use the 
placement diagram at the back of the manual to help determine the 
correct orientation.

If everything has passed the tests above, then check the voltage at RF 
Board U6 pin 5 - it should be 4 volts (or very close).  If it is some 
other value, you have a problem on the thermistor board (likely a solder 
bridge).

Next, see if the VFO is oscillating at all - put the counter probe into 
TP1 and enter the K2 menu CAL FCTR.  What is the frequency indicated. 
If you are tuned to 4000 kHz, the proper frequency should be 
approximately 8915 kHz, but it is not likely that is true until the 
PLL/VCO loop is operating properly, so just tell us what the frequency 
really is.

Check the frequency at TP3 in the same manner - tap BAND+ and the 
frequency should read near 12100.00 KHz, tapping BAND- should read a 
lower frequency (12 to 13 kHz lower).

Try these tests and get back to us for further steps.  I know these 
tests will not 'cure' anything immediately, but it will tell us where 
you should look next.

73,
Don W3FPR


KU4YP wrote:
> Hello all, 
> 
> 	Well, I hit my first snag. The voltage at R30 is maintained at 2.33
> volts. I checked and made sure the values at C72 and L30 are correct. 
> 
> 	The manual makes reference to checking troubleshooting but when I
> look in the troubleshooting reference, it is not readily visible to me where
> the instructions are. 


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