Re: LF: Idiot's guide to receiving Ebnaut? - Tutorial part2

[Andy Talbot <andy.g4jnt@gmail.com>]

This may not be the most helpful answer, but here are details of a high stability locked LF receiver and associated software I made for compatibility with receiving EBnaut transmisisons last year.   It ignores the soundcard completely, and instead has an external digitiser on a receiver, all locked to an external Rb or Cs reference.

http://www.g4jnt.com/Coherent_LF_Receiver.pdf

Andy  G4JNT

On 23 October 2016 at 17:51, DK7FC <selberdenken@posteo.de> wrote:

Hi all,

I started to write the second part of this tutorial but when finished i was not happy with the result.

The first thing one can say is that you will need a very frequency stable receiver. There is no chance without an external reference signal. For generating wav files using SpecLab you will also have to use a ref signal to compensate the drift of your soundcard. Some people have already prepared things in the past. You can use a 1 PPS signal for soundcard drift compensation or a down divided 10 MHz GPS reference or a stereo soundcard receiving VLF MSK signals on the other channel to compensate the drift.
Also the SpecLab configuration depends on your receiver type.
Now i could simply make some assumptions what your equipment may be but this may be not a good way.
So now i think it's better that we start with one example, one (or more) of the stations who are interested in EbNaut decodes on LF should describe the available system components. Then we can work it out what must be done.
We will need to have a stable RX frequency and a drift compensated soundcard frequency in the end.

So who of those who are interested wants to start?

73, Stefan