Hi Stefan, EbNaut

 

Yes, the message was “DOM”. Pretty predictable, I’m afraid ;-)

 

>> We need about 4 dB more S/N, i.e. a lower noise or 0.3 W TX power :-)

 

Amazing anyway!

 

I have a class D PA almost ready but minimum power I can get is 24W @12V. I can try it at 5V but probably excess 1W

Maybe “too much” power for EbNaut in the EA<>DL path

Difficult concept here. There is NEVER too much power, isn’t it ? ;-)

 

I wonder if there is a way to determine the gain of the antenna and finally the radiated power using this EbNaut measurements

All I know here is the Vrms and the impedance of the antenna. My Rx at 7Km can provide a more stable S/N level

independent from ionosferic changes but again this are relative to noise measurements and  should be calibrated

 

Maybe Paul can measure it and then we can determine the radiated power and consequently the antenna gain ?

 

73 de Luis

EA5DOM

 

 

Luis,

I further analysed the files from your transmission. The best SNR i'm getting (assuming the message is 'DOM') is 9.07 dB from the 2 UTC transmission. We need about 4 dB more S/N, i.e. a lower noise or 0.3 W TX power :-) With 1 W it should be possible to decode your complete callsign! The SNR peaked at a time offset of -0.5 seconds and a frequency offset of -30 uHz, but that does not tell to much at this low SNR, maybe.

Worth to try again!

73, Stefan

Am 13.09.2018 21:43, schrieb VIGILANT Luis Fernández:

Hi EbNaut

 

I will be transmiting an EbNaut message in LF with about 100mW to antenna (not ERP)

during the next 24 h al least

 

Frequency: 137.485Hz

 

Transmissions already started at 19:30 UTC and will repeat twice every hour at minute 00 and 30

 

Coding: 16K21A

CRC: 16

Symbol: 2

Characters: 3

 

Number of bits:864

Duration: 00:28:48

 

Reports wellcome. Let's se what can be donde with really low power

 

73 de Luis

EA5DOM