Bob,
Tonight I’ve been estimating your SNR* at 15-minute intervals and comparing to your SNRs from last night. For the large majority of the 15-minute intervals your SNRs were higher tonight, and for the intervals in which your SNRs were higher tonight, the average difference appears to be almost 3dB.
* (estimated from traces on Hartmut’s grabber; much appreciated Hartmut)
I’m also checking databases of daily solar and ionospheric conditions, for parameters that could help to refine a model based on the data that you and the RX stations are generating.
Thanks in part to your earlier start times, it may be possible to start making and refining some rough predictions of link availability (hours per day) vs distance vs season, for the existing equipment, and a means for you to extrapolate those results for any anticipated mods that you might anticipate.
Are Dex and John on tonight? At 74548.5 and 74547.5? I’ve been looking at signals near those two frequencies the past two evenings, and if Dex is on tonight, his SNR at Hartmut’s QTH dropped while yours rose, which would useful information for a model.
The data that’s being generated is very valuable owing to path diversity from multiple grabbers, cultural noise management at the grabbers (lots of low-QRM intervals), the long collection intervals (allows incorporation of terminator effects and better estimates of mid-day/night attenuation span for integration with parametric models), and the long paths provided by great TX and RX work and coordination between TX and RX. It’s a pleasure to be able to view data of this quality.
By next weekend I will have some plots, the first piece of a propagation model and reference documentation for the model that I’d like to pass along if anyone’s interested. Could I send them to you? If after looking at them you think anyone would be interested, perhaps you know of a place to post them.
Nice work everyone,
Regards,
Jim
AA5BW
Markus;
I see the solid three letters on 74.5495 and some traces on .5485 that would be Dex, X/5 in N.C.
Will be on starting around just after 2200 for the evening-thanks, and congrats on the successful OPDS decodes of last night!
Bob
From: [email protected]
To: [email protected]
Date: Sun, 13 Oct 2013 22:37:02 +0200
Subject: Re: LF: RE: 74.5495 will spark-up at 2200 for the evening...
yesterday I made up a simple receive diplexer, so that I could monitor 74.55 kHz between my own LF Opera-32 transmissions. Static levels were quite low, and I was lucky enough to capture a "4 XR" fragment between 1:00 and 1:40 UT:
74 kHz grabber will be online again tonight:
(DF6NM in Nuernberg, JN59NJ)
Sent: Sunday, October 13, 2013 2:50 PM
Subject: RE: LF: RE: 74.5495 will spark-up at 2200 for the evening...
Jim;
Yes, I fired up at a couple minutes after 2200. Was still full light out here. Temp hit 80 yesterday and was still 60 at midnight. I saw Hartmut's grabber very impressive.
Dex, WG2XRS/5 in NC was also on and some of the reported captures show some good hits on him-he was on 74.5485, one Hz below me.
Bob
From: [email protected]
To: [email protected]
Date: Sun, 13 Oct 2013 00:56:15 -0500
Subject: LF: RE: 74.5495 will spark-up at 2200 for the evening...
Bob,
Nice signal! I watched Hartmut’s grabber tonight (thank you for the dropbox Hartmut); it was quite interesting to watch the day to night dynamics, especially between 2300 and 0300. Your signal seems to appear shortly after 2330; did you switch on at around 2200?
Regards,
Jim
WG2XRS/4 NY with plans changed so that will be on till 0600+ with QRSS 60-hopefully with company, /3& /5.
