Hello all,
I will listen/look for Stefans signal from my Shack. Unfortunately I will have
not enough time for a trip to the countryside tomorrow.
After Stefans surprising announcement I did some receiving tests today. I hear
and see all Alpha stations with good S/N. Unfortunately there is much QRM
exactly between 8,5 and 9 kHz. So catching Stefans might be difficult. We will
see.
The Distance form Stefan to my QTH is about 160 km.
The main configuration will be my 10h/20t T-antenna with the AATIS VLF-receiver
I built some years before. He has some active filtering and is usually doing a
good job. It is connected directly to the line input of the soundcard.
My MV-62 selective level meter will also get a chance instead of the
VLF-receiver.
Stefan, good luck ;-)) - and also to the RX operators
Horst
-----Ursprüngliche Nachricht-----
Von: "Stefan Schäfer"
Gesendet: 02.04.2010 13:09:33
An: [email protected]
Betreff: AW: VLF: 4th VLF experiment by DK7FC/p
>Hi Gary, VLF, LF,
>
>The locator is JN49IS. In older mails i have given you the exact coordinates.
>In google maps you can find the QTH within a sector of some 10m.
>
>QRG is 8,97000 kHz. The 4mHz settings is optimal! If the SNR will be good, you
>can try 8mHz as well or 15, like Markus did it at the end of the tests. 15mHz
>seems to be optimal for DFCW-120 but i will start with DFCW-600...
>
>I will have no internet access until saturday night, so cu after the
>experiment.
>Hopefully the wind will be strong enough, the forecast shows about 20km/h from
>south. This would be enough...
>
>Best 73 es gd RX! :-)
>
>Stefan/DK7FC
>
>________________________________
>
>Von: [email protected] im Auftrag von Gary - G4WGT
>Gesendet: Fr 02.04.2010 11:52
>An: [email protected]
>Betreff: Re: VLF: 4th VLF experiment by DK7FC/p
>
>
>Hi Stefan, LF,
>
>I will be monitoring your frequency using a M0BMU type 30 turn 0.8M square
>loop and 9kHz pre-amp into my PC sound card, software is SpecLab running
>Marcus's "9kHz_4mHz" configuration. This loop system has increased my
>reception of the Alpha signals by about 10db giving up to 25db SNR. Thanks to
>Jim for a great design.
>
>Stefan, can you tell me the QTH locator for your Tx site please.
>
>Good luck with the 4th test.
>
>73
>
>Gary - G4WGT.
>
>
>2010/4/2 Stefan Schäfer
>
>
> Dear group,
>
> After a break of one week i plan to transmit again on VLF / 8,97 kHz. If
> the wind will be enough i will come up on saturday, 3. April, at arround 10
> UTC.
>
> The DFCW-600 mode was a good choice in the last experiment, so i will keep
> this mode.
>
> If Markus/DF6NM has time to make QSP on the mobile phone to the reflector
> (Markus ?) we could arrange various tests. I will also call other local
> stations for reception reports during the transmission.
>
> There will be some new components to test:
>
> Today i started building up the 600W class D PA (at least 600W) that is
> directly fed out of the 230V (rectified) of the generator. PTT and VFO input
> is realised by fiber optic cables. The DC capacitor is 2000µF/350V and can be
> put on voltage without a NTC or charging resistor due to the relatively high
> output impedance of the small generator (tested). This works very fine now.
> Tomorrow i will apply the FETs and the big ferrite core and it's windings.
> Then i will do a test on a dummy load at home. If the signal will be 3dB
> stronger, we could theoretically change to DFCW-300 compared to the last
> experiment. But there are many OMs writing private mails to me and prepare to
> be QRV on this next test. Some of them are using E-Field antennas and/or are
> more than 860km away, that' why i want to stay in QRSS-600 first. So there
> might come a new distance record? In any case it will be exciting to me
> watching the new system running :-) Also it will be interesting to see if the
> E-field antenna will get the signal!
>
> The primary winding of the TX coil is increased from 9 to 13 turns due to
> the higher power that will be applied. Otherwise the current will become to
> high.
>
> I will mount the amperemeter (analog, 1A) into the coil. That makes it
> easier to adjust to resonance and watch the stability and maximum and average
> (estimation) current.
>
> Finally i will try to apply some copper rods into the earth and will look
> how the antenna current is changing.
>
> The goal is to radiate 4mW ERP. Another goal is to reach as many stations
> as possible. So i would be pleased if YOU would be one of them. :-)
>
> Since the QRM/QRN comes up in the late afternoon and transmitting for 4...5
> hours i will close at about 15 UTC. So the planned LF activity is not
> affected :-). Sorry, but i cannot participate on the LF acty later since the
> VLF coil takes all the place in my car ;-)
>
> I looking forward to this experiment and wish you good luck and fun by
> receiving :-)
>
> 73 es gl, Stefan/DK7FC
>
> PS: Could you give me a short feedback if you plan to be RX?
>
>
>
>
>
>
>
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