[Elecraft] K3 on-channel strong signal overload?

[Leigh L. Klotz, Jr WA5ZNU]

Jim,
I have some questions.
> DUH! Why are you surprised by this? You had the K3 set for maximum 
> sensitivity and then hit it with a 100 watt transmitter. OF COURSE 
> it's going to overload! 
I don't think this is follows naturally.  Doesn't the automatic gain 
control ("AGC") do the same thing as the RF gain control?  As Oliver 
pointed out, he didn't have the preamp on.

It seems to me Oliver is describing a failure of the AGC to properly 
engage the HAGC , staying only in the DSP gain control area.
I've asked Oliver to report the firmware version, as I believe there 
have been updates in the firmware since the "official" release that are 
in the beta releases only.

>
> These are fundamental concepts of radio. It's too bad that they are seldom 
> taught today. Most of us old farts learned them as Novices when we put our 
> first rigs on the air. In those days, there were no transceivers. You had a 
> transmitter and you had a receiver, and when you transmitted your receiver 
> overloaded. 
>   
A few minutes of search would have shown that Oliver is the person who 
originally reported this problem with the K2 in 2003, which resulted in 
the back-to-back diode clamp.  You may be right that Elecraft doesn't 
design for strong in-passband signals, but it's not clear that that's an 
fundamental limitation of RF technology, especially since the RF gain 
control can handle it manually.  It doesn't seem to me an unreasonable 
request that the firmware be able to detect this same situation and 
properly handle the gain stages (hardware and DSP) at least as well as 
manual RF gain control.  You might want to re-read this message: 
http://www.qsl.net/ve3mcf/elecraft_reflect/K2_Howling_Fix.txt


Leigh/WA5ZNU