[Elecraft] K3 Overload from WYFR

[Joe Subich, W4TV]

I would be checking your system (including the antenna and 
nearby structures) for problems ... I'm a whole lot closer 
to WYFR (105 miles) and they do not generate any overload 
or "buckshot" on my K3 with SDR-IQ and SpectraVue.

73, 

   ... Joe, W4TV 
 



> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Steve Ellington
> Sent: Sunday, June 14, 2009 8:32 PM
> To: Elecraft at mailman.qth.net; LP-PAN at yahoogroups.com
> Subject: [Elecraft] K3 Overload from WYFR
> 
> 
> 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 
> 
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