[IRCA] [NRC-AM] Reviewing SDR DX

[Mark Connelly <markwa1ion@xxxxxxx>]

For home DX captures, I look at a few key channels in a given file to 
see if conditions are better than average (or at least average) for 
either (or both) transatlantic or Latin American targets, my primary 
interests.  The 10 minute conditions spot-check will dictate how 
worthwhile it will be to invest further listening time.  Just as in 
live DXing.

The half dozen or so beach DXpeditions I do over the course of the year 
are reviewed in much greater depth since the DX possibilities are 
substantially better, both because of less electrical noise and because 
of better foreign DX resulting from near-field salt water on bearings 
towards those targets.  The DX to domestic pest signal ratio is 
substantially better on beach outings than from the house even though 
the drive time to the DXpedition sites is typically under a half hour.

One bottom-of-hour and two top-of-hour shore location grabs of 150-1750 
kHz (at 4 min. per capture) around sunset (e.g. centered on 2100, 2130, 
2200 UTC this time of year) typically provides enough material for 
about two weeks of casual after-the-fact DX review.

External hard drive space is cheap these days (2 TB for under $100) so 
I do save some Perseus captures that have not been fully reviewed in an 
immediate time frame.  Besides potential "when I get around to it" 
analysis for DX, they could also be useful for the audio contents of 
the programming, even on "pest" locals, in the case of preserving news 
about certain events, airchecks of stations that go silent later, or 
the voices of DJ's, sportscasters, newscasters, talk hosts, and 
politicians who later become more famous (or infamous) or who pass away.

Really doggy captures (full of noise, "naff" DX conditions, etc.) are 
deleted but so far I do retain over 50% of at-home stuff and pretty 
much everything from seashore DXpeditions.

Mark Connelly, WA1ION
South Yarmouth, MA

<<
I'm curious to hear how other DX'ers tackle "data management" when it
comes to the use of I/Q recordings from SDR receivers. My SDR-IQ allows
me to record 192 KHz of bandwidth, and using HDSDR software, I've
started recording TOH periods overnight. I record about four minutes 
per
hour, starting at local sunset and continuing through sunrise.

This provides a total of 19 MW channels to be reviewed per hour,
Recording for 4 minutes over a ten hour period, leaves me with 760
minutes of data to be reviewed daily. Some channels are nearly
impossible to find new ones on, so these can be reviewed quickly,
checking only for unusual conditions. But it's still a massive amount 
of
data.

Since starting this just a few days ago, I've already deleted days of
recordings, unchecked, simply because there is no practical way to
review it all. Perseus owners would have an even bigger issue, due to
the much wider bandwidth that can be recorded. The entire AM band for
instance!

What strategies have other DX'ers found successful for managing the
data? I've considered recording just the sunrise/sunset periods, or
waiting for a night with unusual conditions to record TOH ID periods
only, or even simply recording for a week in mid-winter, then taking my
sweet time to review them during the summer.




--
--
73,

Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
EM63nf

6M VUCC #1712
AMSAT #38965
Grid Bandits #222
Southeastern VHF Society
Central States VHF Society Life Member
Six Club #2484

Active on 6 Meters thru 1296, 10GHz & Light
> >

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