Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: TXing WSPR on 630m on a Raspberry Pi, Stefan in QRPPPP...

To: [email protected]
Subject: LF: TXing WSPR on 630m on a Raspberry Pi, Stefan in QRPPPP...
From: DK7FC <[email protected]>
Date: Wed, 18 Mar 2015 21:45:09 +0100
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=from:message-id:date:user-agent:mime-version:to:subject:references :in-reply-to:content-type; bh=IKdScFVysfKBNj6CCSdstJqPuENWI0IxCCNNwCiXkJQ=; b=wiB95jOnl/aMHilOyTeEWChgatgQvKrBNwgOOV12U1R5Di36FhlllCYQX7iG2qE8KB sf/ldCU9/XJlcSt1I54MU4iBtyOWRZnRCTnsGHsHn5on7imx7gr1wWgWHScdCf02DqQg EZLGbMKSpy2YI/e6nu4R+Q8oC2niN0dd7xshdfmarH/il1UEtmn7Q1M8rFUEt0nzNkEZ ddtsTQUV/Zy7NLpr0W12qNs+ZytfLB9bFBF9gnxZ9MaC1lSl+jg56gBKmhjMVdoqokYm 0DkRMhqfneXRH/6it0QCPTXnqzs3rcwgFeFt7vX4LMXO3tNOg/aFNkioQYoRGl08Ie0L evDQ==
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
Hi MF,

Today i've got i 3rd Raspberry Pi. I quickly installed the WSPR softaware and since a few minutes i am transmitting WSPR-2 on 630m, my usual frequency 475.685 kHz.

I'm directly using the GPIO output pin, without an amp stage behind! The rectangular 3.3V output voltage is passing a cap and an isolation transformer (FT50-77) as well as a simple pi-filter, because it is a Raspberry pi! ;-)

See: https://dl.dropboxusercontent.com/u/19882028/MF/Raspberry%20Pi%20B%2B%20WSPR%20TX.jpg

I measured an output power of about 10 mW at 50 Ohm. It is now connected to my MF antenna and transmits in a 100% duty cycle. I still have to learn how to reduce it but this will not take long.

With 10 mW TX power i managed decodes by 3 stations now.

3 spots:

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2015-03-18 20:32   DK7FC   0.475684   -21   0   JN49ik   0.01   DH5RAE   JN68qv   345   98 
 2015-03-18 20:12   DK7FC   0.475685   -24   0   JN49ik   0.01   F1AFJ   JN06ht   667   247 
 2015-03-18 20:06   DK7FC   0.475683   -27   0   JN49ik   0.01   DL1DBC   JO41bi   217   349 


Does someone have good ears to get a decode from me? :-) It is a challenge! :-)

73, Stefan/DK7FC

PS: The signal is so weak that my RX antenna frontend is not overloaded, so at that power level i can transmit and receive to the same time :-)
PPS: A small amp stage will follow soon, i intend to use an BS170 running at 5 V.
<Prev in Thread] Current Thread [Next in Thread>