[Elecraft] K2 KPA100 Adjusting R26 and R27

[Don Wilhelm]

  Michael,

Sorry about the blank message - messy mouse clicking!

Check the value of R26 and R27, they should be 100k (labeled 104).  
Check the orientation of diodes D16 and D17 (the cathode identifying 
bands should be toward the left if the rear panel is to the rear and you 
are looking at the component side of the board).

Are you using a DMM?  If you are using a VOM to measure resistance, the 
voltage may be causing the diodes to conduct.  Try reversing the leads 
of the DMM.

Yes, unless you have something wrong, you should be able to adjust the 
trimmers to 43k - the trammer resistors should be the only thing that is 
conducting in the circuit and you are measuring the resistance between 
the midpoint position of the trimmers and ground.

73,
Don W3FPR

On 2/21/2011 6:52 AM, Michael van Hauten wrote:
> Hi elecrafters
> i am building up my 2nd KPA100 and i got some problems when i had to adjust R26 and R27 to 43 ohms.(see page 48 ). in the manual This was not possible. I could only reach 38 ohms. Adjusting the swr in the next step was no problem and i could easily reach 1.0 to 1. Is there a problem anywhere or is this within the normal tolerance?
> Thanks for your assistance.
> Michael, DC0ZO
>