[Lowfer] DK7FC WSPR15 alert ... again tonight

Michael Sapp wa3tts at verizon.net
Thu Feb 6 11:32:04 EST 2014 

Thanks for sharing QRM status Jay. I just did a quick check using WSPR2 at 
137 kHz and it appears that my mixer is not at fault....tests with 3 and 10 
dB pads between the antenna and converter showed only 3 and 10 dB reductions 
of the offending signal....

73  Mike wa3tts


----- Original Message ----- 
From: "Jay Hainline" <ka9cfd at mtcnow.net>
To: "Discussion of the Lowfer (US, European, &amp, UK) and MedFer bands" 
<lowfer at mailman.qth.net>
Sent: Thursday, February 06, 2014 11:08 AM
Subject: Re: [Lowfer] DK7FC WSPR15 alert ... again tonight


> No luck here with DK7FC. I also have local QRN that tends to kill 136 KHz
> WSPR-15 reception at times.
>
> Jay Hainline KA9CFD
> Colchester, IL
> On Feb 6, 2014 9:28 AM, "Michael Sapp" <wa3tts at verizon.net> wrote:
>
>> Doug, Jay & All:
>>
>> Interesting that Doug also had no captures in the 0300 and 0400 hours.
>> Similar result here past two nites...gap from 0230 through 0530 last nite
>> and 0330 to 0630 the night before.  I've had a few DK7FC sequences in 
>> those
>> time frames that might have been "capture-able" if it were not for local
>> compact florescent lamp 2nd harmonic QRM wandering across Stefan's 
>> 137.610
>> signal the past few nights.  The CF fundemental energy is fairly strong
>> around 68.8 kHz in the 1,000uV range and comes and goes here. Likely a CF
>> lamp in the local neighborhood on it's last legs leaking energy into AC
>> wiring.   Second harmonic in the 136~138 range is audible, perhaps S3 or 
>> so
>> and wandering around.  The problem is not in my house so it is not
>> controllable at the source.  When the 68.8kHz energy goes away, so does 
>> the
>> noise in the 136 ~ 138 range.   Otherwise I seem to hear OK in the 
>> 136~138
>> range when the local noise environment is low....
>>
>>
>> 2014-02-06 07:00   DK7FC   0.137611   -38   0   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>> 2014-02-06 06:30   DK7FC   0.137611   -37   1   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>> 2014-02-06 05:30   DK7FC   0.137610   -36   1   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>> 2014-02-06 02:30   DK7FC   0.137610   -39   -1   JN49ik   1   WA3TTS
>> EN90xn   6636   298
>> 2014-02-05 07:00   DK7FC   0.137610   -41   0   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>> 2014-02-05 06:30   DK7FC   0.137610   -35   1   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>> 2014-02-05 03:30   DK7FC   0.137609   -35   1   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>> 2014-02-05 03:00   DK7FC   0.137609   -35   -1   JN49ik   1   WA3TTS
>> EN90xn   6636   298
>> 2014-02-05 02:30   DK7FC   0.137609   -41   1   JN49ik   1   WA3TTS 
>> EN90xn
>>   6636   298
>>
>>    I had given some thought to changing the gain resistor on the MC1496
>> active mixer in the Heath converter to possibly lower the intermod
>> potential.....there is enough system gain to turn the mixer gain down a
>> bit.....then again, one would think the MC1496 could handle 1,000uV at 68
>> kHz without generating significant intermod products.  I may do the 3dB
>> attenuator intermod test on the VLF converter input this afternoon to
>> evaluate.....
>>
>> Thanks in advance for the bandwidth....
>>
>> 73,  Mike wa3tts
>>
>>
>>
>>
>> ----- Original Message ----- From: "Douglas D. Williams" 
>> <kb4oer at gmail.com
>> >
>> To: "Discussion of the Lowfer (US, European, &amp, UK) and MedFer bands" 
>> <
>> lowfer at mailman.qth.net>
>> Sent: Thursday, February 06, 2014 5:56 AM
>> Subject: Re: [Lowfer] DK7FC WSPR15 alert ... again tonight
>>
>>
>>  Thanks for the info, Jay. Success here.
>>>
>>> -Doug
>>>
>>> 0200 -32 0.8 0.137612 0 DK7FC JN49 30
>>>
>>> 0230 -37 1.5 0.137612 0 DK7FC JN49 30
>>>
>>> 0500 -35 1.8 0.137612 0 DK7FC JN49 30
>>>
>>> 0600 -37 1.8 0.137612 0 DK7FC JN49 30
>>>
>>> 0630 -35 0.4 0.137612 0 DK7FC JN49 30
>>>
>>>
>>> On Wed, Feb 5, 2014 at 6:07 PM, <jrusgrove at comcast.net> wrote:
>>>
>>>  DK7FC transmitting WSPR15 on 136.000 (dial). Appears to be running his
>>>> usual +1610 and 1st and 3rd quadrant of the hour.
>>>>
>>>> Jay W1VD  WD2XNS  WE2XGR/2  WG2XRS/2
>>>>
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