Re: VLF: Carrier on 4470.005 Hz!

[Markus Vester <markusvester@aol.com>]

> Is DL0AO ready for an EbNaut test on 4470.005?

Yes, go ahead...

73, Markus

-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 20. Aug 2017 22:23
Betreff: Re: VLF: Carrier on 4470.005 Hz!

A very clear and stable trace at DL0AO, about 16 dB SNR in 31 uHz.

Anything on Pauls RX?

Is DL0AO ready for an EbNaut test on 4470.005?

73, Stefan

Am 19.08.2017 14:59, schrieb DK7FC:

...Rather 5 uW.

Am 19.08.2017 14:28, schrieb DK7FC:

Hello VLF,

I un-wound the defective stack of the large coil which was used for 2970 Hz. It took about 4 hours to carefully unwound about 1000 turns, or about 1 km of wire. The wire will be used for new coils which are already planned.

Now, the remaining 4 stacks should hold at least 15 kV. I connected the coil to the antenna and found the resonance close to 4470 Hz.
Now i'm running (since 12 UTC) a carrier transmission on 4470.005 Hz. The antenna current is just 150 mA. That's an ERP of about 3 uW. A first signal on the 67 km band from here :-)
Let's see how long it holds until there is the next fault :-/

Reports/Spectrograms welcome...

As usual there is a monitoring of the signal in 3.5 km distance from my tree grabber: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html

73, Stefan

Am 13.08.2017 22:17, schrieb DK7FC:

The repetition of yesterdays message failed. At 15:38 UTC the safety function tripped. I've just been on the roof, when re-starting the transmission i can see a spark in the center of one of the stacks. So now there is another one which has a flash over! :-(
It must be replaced, which is a lot of work. So the tranmissions on 3675 Hz will stopp for some time. At least we have some carrier detections and even EbNaut decodes.

I need to think about a different coil concept.... More current, more voltage, more power, more more more!