[Elecraft] K2 alignment part 2 question

[Don Wilhelm]

  Ron,

It is very difficult to detect a 2nd pulse on the DAC2CS signal with a 
regular 'scope - a digital 'scope that is conditioned to trigger on 
events where DAC2CS goes low is required to capture the culprit.

Did you confirm that U5 pin 7 goes to a high state and stays there when 
BAND- is tapped?
It should do that.  If it stays high for a while and then goes low, the 
problem has to be that the DAC2CS went low in the interim period.

Failure of parts in any kit is a rare thing.  Assembly problems are the 
usual cause of failures.

73,
Don W3FPR

On 7/8/2011 7:39 PM, R Thompson wrote:
> Hi Don,
>
>      I took it in to work today, to use some of the test gear during my
> lunch hour.  U5 pin 3 (LD/CS) looks good.  There is a steady high on
> this pin (measurements made on the IC pins, not on the board, to rule
> out soldering problems at the board) with good well shaped pulses
> pulling it low.  Pulses on pin 2, DIN, appear to be OK.  VOUT on pin 7
> makes sharp transitions between the high and low states.  Unfortunately
> I was working with only one scope probe, I really wanted to see if there
> was a second DAC2CS pulse on pin 3 that coincided with the undesired
> toggle back to the high state (on VOUT), but failed to catch it.  My
> lunch time is too short, I used some of it to go over the Part II
> alignment using the calibrated shop gear.
>
>     At the moment, it appears to me that it may be software or digital
> problem.  The software level on my PIC is 2.04R.
>
>     Any thoughts?  Everything else in the part II alignment went well, no
> problems, error codes, or other discrepancies of any kind, thankfully.
>
>                 Ron VE8RT
>