[Lowfer] DK7FC WSPR-15

Sat Jan 19 10:34:31 EST 2013

Jay,

The tuning is done out at the loop with 8 relay-switched caps, in 100pF steps. There is also a relay to switch between 1:10 and 1:5 step up, which helps the Q at the higher frequencies. Gotta write this up. 

JA

On Jan 19, 2013, at 9:56 AM, <jrusgrove at comcast.net> wrote:

>> Perhaps a prelude to a similar thing starting at 6:30 PM on Sunday?
> 
> Hey, I'm pulling for the Patriots, too ... now that the Giants and Broncos have fallen by the wayside ;~)
> 
> Is the loop tuned on the receiver side of the transformer in the shack?
> 
> Jay
> 
> 
> ----- Original Message ----- From: "John Andrews" <w1tag at charter.net>
> To: "Discussion of the Lowfer (US, European, &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
> Sent: Saturday, January 19, 2013 9:39 AM
> Subject: Re: [Lowfer] DK7FC WSPR-15
> 
> 
>> Jay,
>> 
>> My receive antenna now is a single-turn loop, 5' in diameter. It runs through a 1:10 step-up transformer, and then is parallel-tuned and run through a preamp. Performance is pretty close to a 10-turn loop of that diameter. Gotta write all this stuff up, someday...
>> 
>> Anyway, it was a rare victory for the Massachusetts team last night. Perhaps a prelude to a similar thing starting at 6:30 PM on Sunday?
>> 
>> JA
>> 
>> On 1/19/2013 9:28 AM, jrusgrove at comcast.net wrote:
>>>> Jay may be able to shed some light on this, but I had the unusual
>>>> situation last night of producing better SNR reports on DK7FC than
>>>> Jay. That's not normal!
>>> 
>>> Have had this happen ocassionally in the past ... with other receiving
>>> stations as well. The most likely explanation involves antenna patterns
>>> and thunderstorms.
>>> 
>>> Last night, as a good example, I didn't notice anyone complaining about
>>> lightning static even though I was experiencing moderate, to at times,
>>> above moderate static levels. A look at the lightning map gave a good
>>> indication of the likely culprit ... check out the area in yellow circle at
>>> 
>>> http://www.w1vd.com/Tstorm.gif .
>>> 
>>> The antenna in use at W1TAG (box loop ... assuming it's the same old
>>> antenna!) with a figure 8 pattern places a fairly wide null in the
>>> direction of the yellow circle when aimed at EU. On the other hand, the
>>> K9AY in use at W1VD has a cardiod pattern with the response down only
>>> several dB in the direction of the yellow circle due to large frontal
>>> lobe. A quick comparison of the two patterns at
>>> 
>>> http://www.w1vd.com/Figure8Cardioid.pdf  .
>>> 
>>> I verified this hypothesis (so I guess now it's a theory) a couple years
>>> back by installing a large single turn unterminated loop (figure 8
>>> pattern) orientated toward EU for comparison to the K9AY. On nights when
>>> thunderstorms develop in that area I'm not surprised to take a back seat
>>> while using the K9AY.
>>> 
>>> Jay W1VD  WD2XNS  WE2XGR/2
>>> 
>>> 
>>> 
>>> 
>>> 
>>> ----- Original Message ----- From: "John Andrews" <w1tag at charter.net>
>>> To: <k3siw at sbcglobal.net>; "Discussion of the Lowfer (US, European,
>>> &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
>>> Sent: Saturday, January 19, 2013 8:18 AM
>>> Subject: Re: [Lowfer] DK7FC WSPR-15
>>> 
>>> 
>>>> Jay may be able to shed some light on this, but I had the unusual
>>>> situation last night of producing better SNR reports on DK7FC than
>>>> Jay. That's not normal! Consider:
>>>> 
>>>> Time W1TAG vs W1VD
>>>> UTC dB
>>>> 0000 +1
>>>> 0030 0
>>>> 0100 No W1VD report (-36 from W1TAG)
>>>> 0130 No report from either
>>>> 0200 No W1VD report (-34 from W1TAG)
>>>> 0230 +4
>>>> 0300 +5
>>>> 0330 +5
>>>> 0400 No W1VD report (-31 from W1TAG)
>>>> 0430 +3
>>>> 0500 +3
>>>> 0530 +4
>>>> 0600 +3
>>>> 0630 +2
>>>> 0700 +2
>>>> 
>>>> Jay and I are 70 miles apart, and while I'm closer to the signal
>>>> source, this is a noisy residential neighborhood compared to Jay's
>>>> more rural situation.
>>>> 
>>>> John, W1TAG
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