[Elecraft] troubleshooting elecraft k1 voltage checks

[Don Wilhelm]

Ed,

I am not certain how you have 5.8-6.2 volts at P1 pin 15 and zero volts 
at P1 pin 16.

The number of components you have installed at this point is not large, 
so I suggest you trace the voltage from the input.  Check the following 
points in order (stop when you find one that is substantially lower than 
I indicate because further checking is futile).  I will assume a 12 volt 
power source for the initial readings so adjust anything that I have 
indicated 12 volts as expected for your actual supply voltage.
It may be helpful for you to follow along in the schematic to see "what 
is connected to which".

The center of the coaxial power jack (J4) - expect 12 volts
The anode of D16 - expect 12 volts
The cathode of D16 - expect 12volts minus 0.3 volts
Both ends of the RFC8 position on the bottom of the board (RFC8 is a 
jumper at this point) - expect 12v minus 0.3v.
The "IN" pin of U5 - expect 12v minus 0.3 volts
The "OUT" pin of U5 - expect 7.5 to 8.5 volts
The "IN" pin of U6 - Expect same as above
The "OUT" pin of U6 - expect 5.8 to 6.2 volts.

If all those are correct (these are the voltage sources), check the 
soldering at the U6 "OUT" pin and U3 pin 6, and check the soldering at 
P1 pin 16.

73,
Don W3FPR


E Neubauer wrote:
> Hello:
> I am in the midst of building the rf board for the K1.  All went well until page 30 in the manual.  
> I performed the voltage checks and the only one that works is the one at p1 pin 15.  The others read "zero" on my DMM.  I rechecked all soldering - no solder bridges or cold joints.  I went back to the beginning of the rf board assembly and double checked every component's installation and orientation - all fine.
>
> Has anyone got suggestions about where to start to diagnose the problem?   Thanks very much.
> Ed
>   
>