[Lowfer] DK7FC WSPR-15

[wa3tts]

Garry: Thanks info on the spur line, I was thinking it was local. I seem to also have some  wandering switching supply noise that seems temperature related  and some freq or phase mod "berrapp" noise around 136..137 similar to what I hear near DF on 350 kHz.

    I put up a second EWE to NW yesterday but ran out of daylight before I could get a good piece of RG6QS and CM choke to it. Right now it's on a 100ft piece of RG59 extended from my original SW EWE feedline. Pattern seems OK, perhaps I can get the cable and choke on this afternoon. MP was substantial on it and I heard IL and IN on 353? (International Falls and Kansas City) NDBs fairly well.  A few XGP captures on it late morning...went  for  3hrs on 630m last nite with the wrong LPF in line. Got up around 5am and caught the error... getting XXM and XIQ down 5 or 6db may help with the west coast captures.  Did see a plus 9 from XKA at one point so it may only be down 3db or so to the NE from its 320..330 deg main lobe heading
I need to confirm that bearing as well this afternoon....

    Question for you since you are familar with the Isotemp OCXO's, can the 24 V heater line contribute noise to the osc?  I think I have a molded choke on that line as well as good bypass caps, but if I do have a molded 1/2w choke on it the value is likely 4.7mH or possibly 1mH.  Those molded choke have substantial DC resistance (30 ohms for the 4.7mH).  I know for sure I have a 4.7mH molded choke on the osc B plus line, but it only draws 25ma and I'm powering it on a 15V  B plus rail, so I can afford a volt of voltage drop there.  Cant say the same for the 2N5109 preamp and osc driver amp.  Over the weekend I made and installed higher value chokes in the 22 to 24 mH range that only have .1 ohm dc resistance. The chokes take a few hours to build and install, so if the chance of noise contribution is small on the OCXO heater line, I don't want to spend the extra effort.....

I'll pass along the choke info this evening as I do not have access to that info at the moment....portable now at RMU.....

Sri for being longwinded.....73, Mike wa3tts
    






Sent from Samsung tablet.
-------- Original message --------
From: Garry Hess <k3siw at sbcglobal.net> 
Date: 02/09/2015  9:38 AM  (GMT-05:00) 
To: lowfer list <lowfer at mailman.qth.net> 
Subject: Re: [Lowfer] DK7FC WSPR-15 

-------- Original message --------
From: Garry Hess <k3siw at sbcglobal.net> 
Date: 02/09/2015 9:38 AM (GMT-05:00) 
To: lowfer list <lowfer at mailman.qth.net> 
Subject: Re: [Lowfer] DK7FC WSPR-15 

Mike, I looked too but nothing noted here other than a constant weak 
spur practically on top of DK7FC's frequency. Interesting that it's 
present in your capture too so it must not be local. As mentioned before 
I'm not seeing RTTY from HGA22 and DCF39 like last year when DK7FC did 
decode here.

Incidentally, lowfer WM is not currently visible here, after a few days 
of very strong signals. EAR, MLS, and MP are coming in fine so think WM 
has issues again.
-- 
73, Garry, K3SIW, EN52ta, Elgin, IL
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