10 kHz-150 kHz Band Sweep from EN70 Indiana


Hi Dave. This sounds like great fun ! I cannot wait to DL all of your recordings and have a look.

Last night I made a scan from 10 kHz to around 150 kHz using the RSPdx and a 75m inv-v at 70'. The URL is below. It is a large file but who cares.....well worth it IMO. fascinating like you said to see what some of the signals we try desperately dig out of the noise are blasting in for you and vice-versa. Here is my recording from last night.

Do let me know if you would like a future recording changed in any particular way or a different antenna or any particular frequencies or at a certain time etc etc. I will be more than happy to do so. It is great to find someone willing to collaborate with. 73 and let me know how I can make things better for you and I will do the same when I review your recordings.


Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 7/5/2021 11:28 AM, D R via groups.io wrote:

Hi Gedas,

I think it would be easier and much more fun for all if I just put some recordings up, then you can spend as much time as you want going through them and identifying the signals (naval, time, navigation, grid sync, mysterious, etc.) for yourselves.  I've created a Dropbox folder here:  https://www.dropbox.com/sh/t1pqcqvs93vqjle/AAAMm9XIH8FyAE4Fx9kmA8wOa?dl=0  which has some more SAQ pics, a recording of the second transmission (I also have the first, if you want it), and a midday VLF recording from today, covering 10 - 200kHz.  The signals you can pick up don't change much throughout the day, except that the clusters of carriers at 16, 32, 48kHz from my solar panel microinverters won't be there after sunset, but there will be a lot more storm noise instead.  Thunderstorms over Europe are very active at the moment, but if they quieten down I'll do another nighttime recording for you.  By chance, the LORAN transmitter about 70mi from me is down at the moment, so the spectrum between 90 and 120kHz is open, instead of being a wall of solid white (the signals visible around 110kHz are probably down to low power testing of equipment at the transmitter).  There are no Russian Alpha transmissions on at present, unfortunately!

The recording today was made on an HF+ (with R3 shorted) and a Wellbrook LFL1010 loop turned E-W.

If you want to post a recording or two, I'd be very interested to see what it's like on your side of the Pond!



Hi Gedas,

Can you post a recording direct from SDRC, please?  It would be nice to be able to dive into the waterfall and look at some of the weak signals close up, although it was easy enough to pick out all the US Navy stations (and some French Navy as well).  A five minute duration is ample, and it keeps the filesize down to about 200MB.

I've added another recording I've just made - the solar panels are gone, the storms aren't too bad, and the LORAN transmitter is back on, but well below its normal power output, so it's all reasonably clear.  DDH47 on 147.3kHz is worth a look, as you can decode it with FLDigi (settings:  RTTY - Custom - 85Shift, 50baud, 5-0-1.5, Auto, 72char.  Use CW or LSB, filter centred on signal.)  I haven't checked it myself to see whether it was actually sending anything worth decoding, but I could always do a much longer recording if you want to try it out (German weather forecasts can make rivetting reading ;) ).