Hi Stefan,
First, I apologize for not answering before.
My knowledge of VLF communication is very limited, but I hope to learn ,
and yes, I know about G3XBM's grate web page. I have read almost every
thing on it . I find his experiments very interesting.
I have been using SpecLab a long time on 10.140MHz playing with qrss3. I
have tested many waterfall programs, but SpecLab is my absolute favorite.
I have been on qrz.com and looked at your systems. I have no ambitions
to come up to the same level with the first. I am concentrating now on
local communications. My latest experiment is with an Earth dipole. I'm
using a 1-meter copper pipe in the ground as one end of the dipole. The
other is connected to water pipes in my house. The distance between them
is about 20m. As a PA I am now using a 150W power amplifier from HH
Electronic (V150-L). This has a 100volts line output (100W RMS at 1 kHz
into 100ohm). I have tested different modes; MSK01 with SpecLab, WOLF,
THROBX and PSKAM10 in Multipsk. ZL2AFP's CMSK8, and various versions of
qrss. Right now, I am sending in the qrss120 on 8970 and hoping that an
amateur friend of my about 10 km away, will receive me.
My antenna receiving systems on VLF is not the best. I use my 10X10m
loop in the garden. With this I can receive the Alphas pretty well, but
now I am building an active antenna (after your drawing). It will be
exciting to see how it will work in my neighborhood. I hope it does not
pick up too much noise.
Best regards and 73
Steinar LA5VNA
LOC: JO59JQ
On 04.10.2011 21:20, Stefan Schäfer wrote:
> Hello Steinar and welcome to the group!
>
> Good to hear there is interest on VLF by norwegian radio amateurs.
There is not much coming from LA in the last time, unfortunately. So i'm
happy to read of your interest and experiments.
>
> Well, much has been done on VLF in the last year(s). I expect you know
about Roger/G3XBM's VLF pages at https://sites.google.com/site/sub9khz/ ??
> If not, i would strongly recommend to take a look on that and read all
that is written there ;-)
>
> Many of us have done similar local tests and SpecLab is THE most
useful software here, without any doubts. Even more: Without SpecLab,
most of the VLF receptions were not have been possible, due to its band
limiting and noise reduction technics.
>
> Please, what is your locator?
>
> What about your RX performance on VLF, i.e. how well can you receive
the Alphas and other MSK military transmitters, such as JXN ;-) ?
>
> In a short time i will come back, TXing on VLF with several 100 watts
on a 300m vertical antenna. I would like to invite you to make the first
official DL-LA VLF reception (by amateurs).
>
> If you have any questions about VLF settings on SpecLab, don't
hesitate to ask here.
>
> Best 73, Stefan/DK7FC
>
>
> Am 02.10.2011 13:23, schrieb Steinar Aanesland:
>> Hi all,
>>
>> I am new to the group and on top of that Norwegian so please be nice to
>> me, my English is not the best.
>>
>> The last few days I've been doing some digi mode testing at 8.97 khz;
>> "dreamers band", mostly with use of the QRSS mode.
>>
>> On the transmitter side, I have been using a 5 turn 10 x 10 m antenna
>> and an audio amplifier 100W. The system is feeded with a signal from the
>> program "Spectrum Lab".
>>
>> On the receiver side, I have been using a 70 x 70 cm 60 turns loop,
>> tuned with a capacitor. The loop was connected to the microphone input
>> on my laptop and decoded with "Spectrum Lab".
>>
>> The result has been interesting . With this simple arrangement, I have
>> reach a distance of 2.5 km.
>>
>> Yesterday I tried out CMSK8 made by ZL1BPU Murray. I had to make some
>> changes in the ini-file to get the CMSK work om 8.97khz. The sampling
>> rate was adjusted with the program CheckSR and the transmitting
>> frequency was set to 8970Hz. Waterfall has a 2000Hz limit so this was
>> black and useless on 8790Hz.
>>
>> It would makes it easier to track the signal if the developer could
>> extend waterfall to 10 kHz. I am aware that one can get the view of the
>> waterfall by going down in frequency, but 8.97khz has become a de facto
>> water hole of VLF .
>>
>> The result was exciting. A clean copy of the signal was received at
>> about 2 km.
>>
>> I would also try to test out some of the VLF mode in multipsk ,
>> especially PSK10 and PSKAM10, but I have not find a way to fool the
>> program to work on 8.97Khz yet.
>>
>> 73 and good dx the VLF Steinar la5vna
>>
>>
>>
>>
>>
>>
>>
>>
>
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