[Elecraft] KPA100 Initial Test Problem

[Don Wilhelm]

Gene,

Check RP1 pin 7.  If you do not find close to 8 volts there, you will 
need to track down the source of the problem in the 8R input to the KPA100.

If you find the voltage at RP1 pin 7 is not anywhere near 8 volts, check 
the source - what is the voltage on the K2 Control Board Q2 collector - 
that is the source for 8R.  If the two points have significantly 
different voltages, you will have to find the discontinuity in the 
wires, connectors and PC traces between those two points.

If RP1 pin 7 is OK, but U1 pin 27 is lower than normal, that may be OK - 
pin 27 of U1 is simply drawing a bit more power than usual - as long as 
the 5R and 5T outputs from U1 at pins 13 and 14 work OK, you will not 
have a problem.

73,
Don W3FPR

On 10/25/2011 11:26 AM, Eugene Worth wrote:
> Hello all:
>
> I am building a remote KPA100 in an EC-2 enclosure. The KAT100-2 has already been built and tested correctly.
>
> My K2 is S/N 5717 with firmware 2.04P.
>
> Problem: All the test point voltages are nominal (+/-10%) except U1 pin 27. The voltage listed is 5.8 … I got 3.99 volts. Everything else in the section of initial tests is flawless.
> U1 pin 20 = 5.04
> U1 pin 28 = 5.56
> U2 pin 10 = 13.65
> U4 pin 1 = 13.65
> U4 pin 11 = 5.04
> All of the other values are 0 as noted in the checklist.
> On initial power up, the K2 power supply voltage was 13.8 and current 0.36.
>
> Any hints on where to look for the problem?
>
> Thanks.
>
> gene
> WG7GW
>
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