Re: VLF: Carrier on 8270.005 Hz

[DK7FC <selberdenken@posteo.de>]

Hello Alex,

Thank you for the capture! About 15 dB in 47 uHz, so we still can transfer EbNaut messages, 5 characters should be no problem :-) I would like to test it again but there are really many things to try. The last 2 days were pure carriers for RC4HAA. There are some bright pixels near the right frequency to the right time. But as long as there is no accurate reference signal, it is only guesswork, no clear ID of my signal. So we can try more EbNaut soon and i like to try to come back to 6.47 kHz with a stronger signal. And then there is the new 970 Hz playing field and the 2970 Hz coil must be repaired. So far running 5 kV at 970 Hz with the transformer. I have a 2 nF fixed capacitor that holds 40 kV. When using the repaired coil for 2970 together with the antenna and this capacitor and some (many!) iron powder cores inside the coil i could come down to 970 Hz when running 300 mA into the coil. And then i will get 60 mA antenna current at 970 Hz, a signal improvement of 12 dB. I expect to manage at least 30 km in 424 uHz then, who knows, maybe more...
Just some thoughts about the low frequency stuff :-)

73, Stefan

Am 05.04.2017 17:53, schrieb rn3aus@gmail.com:

Hello Stefan, VLF!
Trace on my vlf-grabber in ko85ha in 47 and 21 uHz.

Среда, 5 апреля 2017, 16:34 +03:00 от DK7FC <selberdenken@posteo.de>:

VLF,

There is a trace very close to 8270.005 Hz on the 47 uHz spectrogramm of the RC4HAA VLF grabber, http://136.su/grabber/
This is a land path distance of 2877 km, http://no.nonsense.ee/qth/map.html?qth=LO53CF34HC&from=jn49ik00wd

Actually the trace appears to be one pixel to high in frequency and it looked to me that it has started a bit earlier than my transmission. So i expect it is not my signal but some local noise. But meanwhile it stays on the QRG quite stable. My carrier is still on the air since yesterday 18:50 UTC.

So, i'll do QSY after 24 hours, at 18:50 UTC the carrier will jump to 8270.000 Hz. Then after some hours we will see what happens! :-)

73, Stefan

Am 04.04.2017 21:43, schrieb DK7FC:

Hi all,

...running 700 mA again since 18:50 UTC. I am testing my new PVC coil housing. It protects the coil from rain and sunlight. Fortunately it is already proved that there are no dielectrical disadvantages (same resonance and Q of the coil). But the open question is how the coil will heat up inside the housing. So this transmission is a test again. But the current amplitude is constant at 700 mA, the phase is stable anyway. So it may be useful for some OMs testing their receivers...
It will be on air long enough to see something in 47 uHz...

73, Stefan