Friday, 24 April 2015

FM DXing: Looking To The Future

2015 will be the first season I have used an SDR receiver on band 2 for sporadic E DXing and this new technology slightly fills me with dread. DXing won't be the same. It will be better, potentially, as I will see more of the band and hopefully miss less, but there are a few things which need consideration.

The Elad FDM-S2 SDR Receiver

When I look back at "Medium Wave DXing Before Perseus", things were simple. DXing was done on one single frequency. DXing was dramatically improved when I got my Perseus. Suddenly I could see the entire medium wave band and DX every single frequency at the top of the hour, resulting in not just more loggings, but more exotic loggings as I wasn't missing anything. My logbook grew enormously, and so did the amount of time I needed to go through all those files. That's not so bad though as you tend to develop your own strategies for analysing and playing back the files, so I got quicker at it over time.

Now I have the Elad FDM-S2 SDR receiver which is capable of recording more than three times the bandwidth of the Perseus. I have already seen my meteor scatter logbook grow dramatically in size as I am able to analyse almost a third of the band at once. I usually record six or seven hours of band 2 overnight, in four stages. SDR Console's File Analyser software makes reasonably short work of the playback by displaying each 90 minute recording in a long jpg file, so I can see the meteor bursts and jump straight to them, saving a huge amount of time.

So come the sporadic E season, when the band can literally fill up with countless stations, I am going to have a lot of data to go through if I decide to record the band and play back the recordings later. This is not helpful to other DXers as I won't be adding anything to my FM List logbook in realtime. This means there will be no indication on the FM List Visual Logbook that an opening is in existence. At least, not unless I (a) send out DX alerts to the groups, or (b) if I don't log at least a few stations 'live' when I first notice an opening. It is my aim to alert other DXers when an opening occurs, but playing back a recording later isn't going to of any use to other DXers. Hopefully (a) and (b) will rectify that issue. But will I have time for that? Sending out alerts takes time.

Recording DX may be a thing of the past, unless I hear something unusual or exotic. I don't think I'll have the extra time for these things.

These days we have the superb FM List where we can manage our logbooks. This simplifies and organises the data in ways which can speed up the logging process. But, in the same way the Perseus increased the number of loggings on medium wave, the FDM-S2 is going to do the same for FM DX but, potentially, on a much bigger scale. I can see DXers getting hundreds of individual loggings in a single opening this way. With this much extra data, we are going to need an even quicker method of entering those loggings into FM List. Automated logging is the answer, which we now have to a degree, but I worry this will take away the fun of DXing as the hobby will then be more about collecting data as opposed to the thrill of chasing the DX.

Being able to DX 60+ channels simultaneously is going to reveal a lot of DX and I like to log everything as this highlights the precise area of an opening on the map with a nice visible footprint. So I need to find a quicker way to add those logs into FM List. Do I simply enter a station in the FM List logbook without including RDS data or programme details? That will speed things up, but at the expense of not providing useful information which, not only provides useful information about a station, but also verifies what I have received. Perhaps I should leave out signal strength and the time too while I'm at it. No, this is not the way to DX. It's all necessary information. I always do my best to assess the signal strength as accurately as possible in my loggings. Programme information is essential. So what ways are there to speed up the logging process?

It would be nice to have a log entry created from the data received by the SDR receiver itself, or from related software. This could automatically go into a log, ready to upload to FM List later, or maybe even uploaded live as a DX cluster. You'd need to create filters and set parameters in order to make sure that not every single station is reported over and over again. I don't like to see too much repetition in loggings.

This highlights the dilemma. Looking back to last year's E season, (yes, the one which almost everybody described as the worst they'd experienced) I used a method of rapid tuning, staying on a frequency long enough to get the RDS, then quickly moving to the next frequency. I recorded lots of videos, some of which are on my Vimeo page. This method resulted in my biggest ever annual Es logbook! And this was the worst season on record! I was about three weeks behind with my logbook at one point. Now look at how many of us have SDRs. Oh dear! Suddenly, things are going to get more complicated.

Of course, we can keep it simple and DX live, one frequency at a time. Absolutely nothing wrong with that. In fact I am almost tempted to stick to that, but I know curiosity will get the better of me and I will want to record the DX. I know it's not all about quantity, as I have often banged on about, but it's also about not missing that brief exotic opening which might is going to be camouflaged in among the regular stuff. SDRs are definitely a step forward in our DX hobby, but at what expense? I think it's time to take stock and decide which way to go. What will the future of DXing look like?

Did I mention the additional drive space and processing power we are going to need? There's only so much we can record, unless we have an endless supply of hard drives.


  1. Interesting reading John !
    Since a few weeks I have also an Elad. I see that you are recording chunks and analyse them with SDR File Analyser. Do you have any issues ? And if no, what kind of set up are you using. I've experienced that you have to be careful and not use too much files at once. Otherwise File Analyser goes into a kind of hanging status. Cpu goes to zero but Ram consumption goes to the ceiling and doesn't really proceed any more. I'm using a dual core laptop of 2 x2.5 GHz and 4 GB RAM. Maybe that's on the low side. What is your experience here and did you run into issues as well ?
    73, Guido

    1. Hello Guido.

      Sorry - I only just saw your message. My apologies for the late reply.

      I have been recording six hours overnight to look for meteor scatter. I use File Analyser to look where the meteor bursts are, then I can jump straight to them in the FDM-SW2 playback. This saves a HUGE amount of time :O)

      My computer is a very fast i7 8GB RAM machine. Even this struggles if I run other software and browsers (especially Chrome) at the same time.

      My five year old (very slow Celeron) Toshiba Satellite laptop with 4GB RAM runs the FDM-SW2 software fine ... providing I don't run anything else.

      Some slower computers run FDM-SW2 very well, while other faster computers do not. A lot depends on the internal hardware, Often this is more important than the speed of the processor.

      Your dual core computer should be fine - I guess. Are there other programmes running too? Some programmes run hidden, in the background. Could this be the problem?

      Hopefully you can get this problem solved. Do you know a computer expert who could advise?

      I hope this has helped Guido.

      Best wishes and best DX!


    2. Thanks for your reply John. I have no isuues runing the FDM-SW2 software. At least as long as I use only one VRX.

  2. Played today with the SDR File Analyser but I missed the RDS button or did I overlook something ?

    73, John/HOL

    1. Hi John.

      I cannot help with SDR Console. I know this is an excellent programme but it is too complicated for me. There are RDS facilities in SDR Console and they are very good. They are located in the "FM Stereo" window, under "RDS". Is the window hidden?

      For RDS decoding I have found there is nothing better, in my own setup, than running RDS Spy from the Elad FDM-SW2 software. You will need to run this through Virtual Audio Cable though, with the sampling rate set to 192 kHz.

      I cannot advise how you set this up as a friend accidentally got this working for me - and he didn't know how it happened either! :O) I could give you my sound card settings but they would be irrelevant as I probably use a different sound card to you - a Midiman Delta 66. It was VERY difficult to set this up and I often have hardware conflicts with the onboard RealTek soundcard due to using this.

      I hope you can get this sorted John. Perhaps somebody on the new Skywaves group could help?

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