Re: LF: 137 kHz WSPR-2 on a 900m long ground loop, this weekend

[Domenico IZ7SLZ <iz7slz.domenico@gmail.com>]

Hello Stefan,

thanks for sharing your amazing experiments ! Please inform us about impedance measurements data.

My LF receiver is online trying to decode WSPR-15, WSPR-2, OPDS32; we are far but i hope to decode you in nighttime, QRN permitting.

This is the link for WSPR decodes:

https://www.qsl.net/iz7slz/OPDS/WSPRDECODED.TXT

The spots are also uploaded to wsprnet.org

Good luck !

73, Domenico IZ7SLZ

On Fri, 7 Sep 2018 at 13:51, DK7FC <selberdenken@posteo.de> wrote:

Genosse Roman, LF,

Yesterday i built a small LF PA providing 10 W at 50 Ohm. It consumes 1
A at 12 VDC. I intend to run an over-night WSPR-2 transmission (20% TX
rate) on saturday night, using the ground loop or earth antenna in
JN39WI. The signal generator is a Raspberry Pi running on a separate 7
Ah lead gel accu. The PA has its own 7 Ah accu. The PA can switch from
2.5 W to 10 W :-)

Will someone catch the signal at all? At least i'm already asking for RX
stations!

I'll carry some measuring equipment there, like my M0BMU LF tuning
meter, some Cs, a T106-2 and some wire, also a small ferrite core to
build a transformer if necessary.
What could the feed point impedance be? I have no idea! My modified
MFJ-259B covers LF but i expect it will be overloaded with strong
signals on the antenna, so i try to match the antenna with the transmitter.

More soon :-)

73, Stefan

PS: Oh, i'm also going to connect two anti-parallel LEDs to the antenna
to see if they shine. It is all a big game for old children!


Am 05.09.2018 23:54, schrieb Roman:
> OK Stefan.
> Try it to do. may be wonderful results.
>
> Roman
>
>   
>> Hello Roman,
>>
>> Yes maybe i'll build a quick PA tomorrow for LF and will transmit on LF
>> for 24 hours, each 10 minutes, WSPR-2. I have no idea at all how this
>> antenna performs on 137 kHz. Is it still a loop or rather a dipole or a
>> mixture? At least it has about the length of a full size dipole for 137
>> kHz. I would TX at 10 W RF power only, so that a small accu covers some
>> hours. But i'm not yet sure if i can find the time to do it tomorrow.
>>
>> 73, Stefan
>>
>> PS: If the antenna acts as a dipole, then it is beaming to Russia directly.
>>
>> Am 05.09.2018 21:42, schrieb Roman:
>>
>>     
>>> Congrts, Stefan!
>>>
>>> We are follow by your success!
>>> Listen, do you planning to operate 136 kHz, I hear, tell me pse - do you planing try to TX with that ant on 477 kHz and 160M?
>>> I will be interestin to hear about results.
>>>
>>> 73!
>>> Roman
>>>