[Elecraft] K2 KX1 K1 More advice sought on Elecraft radios

[Ron D'Eau Claire]

It's true that linearity and low noise are often sacrificed for larger
dynamic range. How much we sacrifice for the performance we need is a
tradeoff that is has been with us for a very long time: ever since passive
detectors like crystals and electrolytic detectors were replaced by the
Audion and its successors.

The common regenerative detector is not only wonderfully sensitive -
matching most of the modern receivers available today - it produces a clean,
crisp audio that is hard to beat. That is, on CW. The common form we usually
see in the old handbooks was a triode "grid leak" detector made to
regenerate. They were not very linear when demodulating A.M., but they
usually sounded better than most of the superhet receivers of their day, and
better than many today.

The underlying problem with a regen, as with any "tuned radio frequency"
(TRF) receiver, is that they are either fixed in frequency with exotic input
filters to provide good selectivity or they are tunable with less complex
input filters and have fairly poor selectivity compared to a superhet.
Indeed a superhet is simply a fixed-frequency TRF receiver with a tunable
"converter" ahead of it, and it's that added complexity that adds noise,
spurious responses and most of the other ills we suffer with modern
receivers.

Like everything else, engineering is an exercise in compromise. Different
compromises are important in different situations. 

Up through the 1990's large ocean-going ships had two independent Morse
stations built into a common console: one was the main station and the other
was a completely independent backup station. The backup station receiver was
usually the one that had become obsolete as new technology became available
sometime in the past. It was common to find the backup was a simple
regenerative receiver. 

One time I overhauled the regenerative backup receiver for a ship. When I
was done I installed it in the console and turned it on to show the radio
officer (Sparks) that it was working. We were dockside in the San Francisco
Bay and as it came alive we were greeted by an awful howl of cross mod and
heterodynes produced by the powerful broadcast band transmitters that
literally surrounded us all overloading it. I mentioned to Sparks that would
not be the case at sea. 

Sparks cast a baleful eye on me, stroked his beard and said, "Sonny. If'n
this tubs a'sinkin in the middle of the ocean and someone's overloadin' this
receiver like that, he's the ship I WANT to hear!"

Sometimes a critical deficiency in one application is a critical advantage
in another.

Getting the most out of any tool requires understanding its limitations and
the knowledge to use it to its best advantage in each situation. That
includes radios. 

Modern radios -- and the Elecraft rigs are no exception - are designed for
specific applications. Then as much flexibility is built into them to take
advantage of changing station environments, band conditions and operator
preferences. That's why they have such a variety of filters, preamplifiers,
attenuators, and other user-selected options.  

Understanding what they do and how to apply them correctly is essential. 

Ron AC7AC