[Elecraft] K2 - Problem With KAT2 Installation

[Peter Barville]

Many thanks once again Don.

I agree with your thoughts, but KAT2 is currently a 'stand alone unit' 
with the RF connectors not connected. I'm only connecting J8.

So, like you, I am at a loss to understand what is happening.

Even with a very strong (and loud) signal at the Rx input, no audio is 
present when J8 is mated with P4. Just a full scale reading on the S meter.

Understood re "keying J8".

73 Peter G3XJS



Don Wilhelm wrote:
> 
> Peter,
> 
> While I should say "That can't happen", it obviously is happening.
> There is no signal on the P4/J8 connector that should cause those symptoms.
> It sounds like, when the KAT2 is connected, there is some signal being 
> injected at the antenna which is causing the AGC to fully activate and 
> that reduces the audio significantly.  I cannot conceive how the KAT2 
> could create an oscillation, it is only an L network with parallel C and 
> series L elements.
> 
> The other possibility is that somehow connecting the KAT2 is causing 
> your K2 to go into transmit - that will create no audio and a deflection 
> of the S-meter - However, if that were true, you could not navigate the 
> menu during transmit, so I don't think that is what is happening.
> 
> Try connecting the cable to CB P4 but do not connect the KAT2 RF input 
> (coax cable) to RF Board P6 - is the problem still present?  If not, 
> then the KAT2 is picking up some strong local signal and injecting it 
> into the receiver.
> 
> What I meant for the keying of J8 was to stick something in the pin 4 
> position on the connector and it will be impossible to plug J8 into P4 
> the wrong way.  Pin 4 has already been removed from P4 during the 
> installation of the KPA100.  Use the same technique to key J8.
> 
> 73,
> Don W3FPR
> 
> Peter Barville wrote:
>> Hello Don
>>
>> Firstly, my apologies as I am currently experiencing a few mail 
>> problems, and this note won't 'flow' as part of the original message 
>> thread.
>>
>> I am very grateful to you Don for your reply. Over the years I can't 
>> imagine just how many you have patiently helped.
>>
>> I obviously didn't explain the problem very clearly, but will try and 
>> clarify things.
>>
>> J8 is oriented correctly, with the green wire towards the top. I have 
>> checked the other end of the cable and confirmed there are no shorts, 
>> or open circuits.
>>
>> As you suggest, P4 pin 4 has been removed as part of the KPA100 
>> installation, but I'm not sure what you mean by "Since you have 
>> already removed P4 pin 4 for the KPA100 you will have U8 also keyed."
>>
>> No doubt I'm being a little slow, but perhaps you would put me straight?
>>
>> To clarify the symptoms (I hope):
>>
>> With KAT2 *not* connected, the rig will power up and perform normally.
>>
>> With KAT2 *connected*, when I power-up the rig, the S meter goes full 
>> deflection, and there is no audio output. However, the rig does allow 
>> me to navigate to, and through, the KAT2 options.
>>
>>   
> 
> 
>