[Elecraft] K3 Overload from WYFR

[Steve Ellington]

A photo (40 meter Overload) has been uploaded to the file section of the 
LP-PAN Yahoo Group. This photo is a screen capture from PowerSDR-IF showing 
WYFR at 6985Khz and the resulting images on either side of the carrier. The 
K3's preamp was off. Turning on ATTN reduces the levels somewhat but the 
images are still present. These images can be seen on PowerSDR all the way 
up to about 7080kHz while WYFR is transmitting however, tuning the K3's VFO 
to 7030kHz or above eliminates all signs of these images. Buckshot 
(distorted bits of modulation) can be heard up to about 7015Khz.
The images shown seem to be generated by the LP-PAN. Clicking on them moves 
them elsewhere and they cannot be heard. Other than the buckshot at the low 
end of 40 meters, audible reception seems to be unaffected however LP-PAN is 
rendered unusable during the evenings.
WYFR is located in Okeechobee, Florida, 631 miles from my QTH in NC. 
Naturally their signal is very strong, 60db+ over S9. The antenna used here 
is a 200ft doublet, ladder line and tuner.
Here are my questions and concerns:
1. Is it normal to expect the K3's front end to overload under these 
conditions?
2. Is it normal for LP-Pan to be rendered useless by strong BC stations 
outside the ham bands like this?
3. Do you think this could be caused by any defect in the K3 or station 
configuration?
4. What kind, if any, outboard filter would help? The internal or external 
tuner has no effect (in or out of circuit).
5. Is anyone else experiencing such an overload?
I'm just trying to pin down exactly where the problem is. It appears that 
the front end in the K3 is allowing too strong of a signal to hit the LP-PAN 
then the K3's roofing filters do their job to protect the K3's DSP.
I have become rather addicted to the LP-PAN. I can't tell how many times I 
have though the band was dead after carefully tuning but a quick glance at 
the screen reveals several stations!
If you are not subscribed to the LP-PAN group, you may view the photo here: 
http://i222.photobucket.com/albums/dd260/n4lq/wyfr.jpg

73 Steve N4LQ

N4LQ at carolina.rr.com