[Elecraft] A few thoughts on the K3 as an AM SWBC receiver

[Bill VanAlstyne W5WVO]

I originally ordered my K3 a couple years ago with the general-coverage 
KBPF3 board, having the intention (When I Got a Round Tuit) to put up some 
kind of SWBC band resonator-optimized wire antenna. Well, I finally got 
around to it. And wow, what a SWBC DX receiver the K3 is! Here's a few 
things I've been discovering the past few days:

First, the world of SW broadcasting has changed immensely since my salad 
days of SWLing in the 1960s. Used to be, when you heard a station you could 
identify as Radio China, for example, you could be highly confident that you 
were hearing a radio signal from China. Not so any more! Many countries now 
lease out powerful, strategically located short-wave broadcast 
transmitters/antennas to the highest bidder, with the program material sent 
directly to the transmitter site by satellite from the country of origin. 
Last night I was listening to Radio China International broadcasting in 
English to North America -- but from Spain, not from China. And I listened 
to Vatican Radio broadcasting to Africa in African-accented English -- but 
from Madagascar, not from Rome. The World Radio TV Handbook (WRTH) makes all 
this clear, after a fashion, but you have to look in three or four different 
places in the book to sort it all out for any given broadcast. (There are 
also many websites that are very useful in making sense of all this. See 
below for an example.)

The K3 offers a lot of options for listening to AM broadcasts. Synchronous 
AM mode, which allows you to listen just to the upper or lower sideband 
(selectable using the SHIFT knob), is a huge benefit over conventional 
double-sideband envelope detection. But my favorite is still USB/LSB, 
because I can tailor the LO-CUT and HI-CUT on either sideband to get just 
the right selectivity for maximum intelligibility of the audio envelope. 
This is highly dependent on the announcer's voice characteristics, as well 
as on band conditions and interference sources.

Setting VFO CRS to 5.0 kHz is also convenient, as the K3 remembers this 
setting for the SWBC band-mode combinations. I tune the standard 5 kHz SWBC 
"channels" with the RIT knob (VFO OFS=ON mode). If a station is 
off-frequency, I can use the main VFO A knob to tune it in.

An amazing website I discovered for the SWL is http://www.short-wave.info. 
On this site, you can type in a frequency in kHz, click a button, and the 
site will report all SWBC stations currently on the air on that fequency 
(+/- 10 kHz), both in graphical map and tabular formats -- the map showing 
the radio information (actual transmitter locations and frequencies), the 
table showing the programming information (country of origin, language 
currently being broadcast, and program start and end time intervals). The 
database appears to be updated weekly. This is just WAY TOO COOL. :-)

SWLing with the K3 is a whole different experience than with 
earlier-generation receivers. With the right adjustments, you can hear and 
actually understand a weak station 5 kHz up or down from a 40-over-9 monster 
station. Adjacent-channel QRM is now a thing of the past. If you haven't 
tried SWLing since you were a kid, you should get the KBPF3 board installed, 
if you don't already have it, and check this out. Too much fun.

Bill W5WVO