[Elecraft] K3: Receiver recovery time

[Dave Cole (NK7Z)]

Thank you Don!!  I was trying to get a general feel for what to expect, 
a  ms, or us type of answer...

I was thinking of using the IF to avoid the DSP filters for just the 
reasons you cited.  I am sure you are correct about testing-- time to 
break out the scope...

Thanks again for your insight!

73s and thanks,
Dave (NK7Z)
https://www.nk7z.net
Award Manager, 30MDG Grid Contest
ARRL Technical Specialist
ARRL Volunteer Examiner
ARRL OOC for Oregon

On 1/13/19 1:08 PM, Don Wilhelm wrote:
> Dave,
> 
> I would be cautious about looking only at the IF.  That is all in front 
> of the DSP.
> Certainly the DSP creates some latency, but that is not what we are 
> talking about.  The DSP latency will delay all signals.
> 
> So test in the configuration that you will likely use.  If using the IF 
> output, then test only at the IF.
> 
> Your question relates to the recovery time for the entire receiver.
> And that does include the filters, both roofing filters and the DSP 
> filtering.
> 
> Don't forget that the Hardware AGC cannot be turned off, but that does 
> not come into play until the signal is greater than S-9+60
> 
> As A result, I believe you need to do actual testing with your 
> particular K3 under various filtering conditions.
> In other words, you are asking a very complex question, and you have not 
> given us the other configuration settings and filters to be used - other 
> than AGC OFF.  For that reason, your K3 may have a different answer than 
> others.
> 
> 73,
> Don W3FPR
> 
> On 1/13/2019 3:43 PM, Dave Cole (NK7Z) wrote:
>> Hi Don,
>>
>> Thanks for the combined brain power!  I have a plan for testing if it 
>> ever gets that far.  I am just trying to see if the K3 receiver 
>> recovers sufficiently fast in a general sort of way first.
>>
>> I believe I could look at RF levels on the IF while transmitting, 
>> (using a different transmitter and a storage scope to look at the K3 
>> IF), then just drop the carrier while still looking at the levels with 
>> that scope.   When I see signals return to the IF I have the recovery 
>> time of the receiver.
>>
>> I am just trying to skip that step hoping someone actually knows the 
>> recovery time of the receiver, as opposed to actual testing.
>>
>> If the K3 is even close, I will set up test jig for it, if not, then 
>> I'll look for a better way.
>>