[Elecraft] SWL Specifics for the KX1

[Phil Wheeler]

Bruce,

A very nice summary of what is out there.  When I travel, camp and 
backpack I do a lot of SWLing.  I'm finding the KX1 (so far at home -- 
I'm on travel restrictions, medically, for a bit) to be a very effective 
SWL rcvr with incidental ham tranceiver capabilities :-)

For example, just now I am sitting in my recliner with my legs up, my 4 
lb laptop in my lap and my KX1 (tuned to Radio Australia on 49 m) 
sitting on the arm of the chair attached to a 20 ft or so wire.  Pretty 
cool!  Now I've retuned to 40 m CW and am listening to  W6QR who is abt 
1/4 mi to the west of me working a W0 on 7031.4.  At last a use for the 
RF gain!  Given that I can seen his stacked D4/D4W from my backyard, the 
combo of RF gain and narrow bandwidth does a good job of keeping his 
signal from overwhelming the radio.

Is the KX1 competitive with consumer SWBC receivers?  I've yet to run 
any concrete tests, but I plan to -- when I get an antenna configured 
that I can connect to both; I have the parts, just need to get it done 
today.  I do know that SWL from here is made difficult on my small SWBC 
receivers by a local 50 kW clear channel AM station about two miles 
away. I hear no evidence of it with the KX1.

SWLing with the KX1 has identified one problem: The computer-type power 
supply I use with my K1 for travel is not so good with the KX1.  The 
wider bandwidths used for SWL (or ham SSB) listening really make the 
hash from the supply much more apparent than with narrow CW bandwidths.  
So I will need to replace that supply (or just go with my existing pack 
of 10 NiMH 2200 mA-h cells as my portable supply).

No question, though:  The small size and the SWL capabilities of the KX1 
have made it my "take everywhere" qrp rig.  Since my K2/100 is my base 
rig, I will have to find a new niche for my trusty (and not to be 
discarded) 4-band K1 :-)

73, Phil

Bruce Prior wrote:

> The KX1, especially with the KXB30 installed, makes an excellent 
> shortwave receiver with the bandpass filter at its widest setting.  
> Double sideband AM transmissions can be detected by zero-beating in 
> LSB or USB modes.  If tuned to the 40 m band, reception is possible 
> from 5.0 to 9.505 MHz; the 30 m band yields a range from 8.0 to 12.505 
> MHz; the 20 m band allows shortwave tuning from 12.0 to 16.505 MHz.  
> The firmware prevents accidental transmission outside of the amateur 
> bands.
>
> With the tiny optional 30 m module installed, the KX1 will receive the 
> 49, 39, 31, 25, 22 and 19 meter shortwave broadcast bands, with 
> somewhat decreasing sensitivity the farther removed they are from the 
> installed KX1 amateur bands.  The broadcast allocations within the 
> range of the KX1 with a KXB30 module installed are 49 m: 5.95-6.2 MHz; 
> 39 m: 7.1-7.3 MHz (moving upward in 2009); 31 m: 9.5-9.9 MHz; 25 m: 
> 11.65-11.975 MHz; 22 m: 13.6-13.8 MHz; 19 m: 15.51-15.6 MHz.
>
> Since most shortwave broadcast stations transmit on frequencies evenly 
> divisible by 5 kHz, the very coarse 5 kHz/step tuning speed makes 
> tuning them convenient.  To calibrate the steps properly in LSB or USB 
> modes, begin in the finest tuning speed and tune until 0.00 or 5.00 is 
> displayed, then push and hold the encoder knob until the decimal 
> marker disappears.  The entire 4.505 MHz range can be covered in 11� 
> rotations of the tuning encoder at 5 kHz/step tuning speed.