[Elecraft] [K2] KAT2 Question

[Brian Handy]

Hi All,

To follow up on this thread for the archives...my problems are resolved.

I actually had two issues:

1 - I had mis-wired J7 on both ends originally!  The instructions are clear, and the proper orientation of the cable is even imprinted on the card, but I looked at the picture and interpreted the floppy-looking conductor as the ground strap ... not the center conductor.  

2 - I stared hard for a while at my toroids and solder joints, and slapped my head in disgust when I noticed that one of the relays was in backwards.  Fixed that, was able to complete the tuning section of the manual, works great now!

On to the KSB2 module ... that's another email.

Cheers

Brian Handy AE7JW


________________________________
 From: Don Wilhelm <w3fpr at embarqmail.com>
To: Brian Handy <holy_tire_iron at yahoo.com> 
Cc: "elecraft at mailman.qth.net" <elecraft at mailman.qth.net> 
Sent: Friday, February 15, 2013 12:53 AM
Subject: Re: [Elecraft] [K2] KAT2 Question
 
Brian,

Are you certain you had the J7 connector backwards?  The coax shield should be toward the right side panel.
The results you are now getting indicate that you have something wrong with what you changed.
That power reading is likely coming from the K2 RF board RF output detector rather than from the KAT2.  If that is the case, the KAT2 is not being recognized - check the connector to the Control Board.

An inability to achieve a null on C55 is usually an indication of a problem with T1.  Check that it is wound in the same direction as shown in the manual.  Check that the proper color leads are in the right holes.  Look at the solder side of T1 - there should be no rings in the solder around the leads - that is an indication that the leads were not well stripped and tinned.
I would suggest removing T1 and re-winding it.  It MUST look just like the diagram in the manual or it will not function properly.

73,
Don W3FPR

On 2/14/2013 9:18 AM, Brian Handy wrote:
> Hey all,
> 
> I've been working on the KAT2 module for my K2.  Mostly making progress but stumped in the bridge null adjustment.
> 
> I was having problems with C55, and getting silly readings on U4 Pin1, so after staring at my board for a while, I went to the web for a while and read about other folks' problems and figured out I had wired J7 backwards on the control board.  I fixed that, which brings us to my problem...
> 
> I set ATU CALn in the menu, exit, hit 'TUNE' like I did before, and instead of getting the mV reading like I was before, I just get a power reading - e.g. "P 4.5".  I can't seem to get back to what I was looking at before.
> 
> I went back and checked the other tests again ... I have everything in ATU mode in the menu, I can make the relays go clicky-click when I run through that set of options in the ATU menu, but I can't get this null mode to work.  I was able to get it to work when I had the RF cable J7 wired up wrong.
> 
>