Re: LF: Re: 477 EA5DOM QRP TEST 1 WATT U3

[DK7FC <selberdenken@posteo.de>]

Hi Luis,

Am 24.08.2016 11:32, schrieb VIGILANT Luis Fernández:

I'm using half ICL7667 on my U3, so that's why power is so low compared to BS170s

But the case keeps cold and helps to avoid DDS drifts during long transmissions

It should be possible to run more power from the 7667. Is it running at 12V? Do you feed the 50 Ohm input of the antenna with the output of the 7667 (and C and a LPF between)? Maybe you can wind a small transformer to come down to 12.5 Ohm. 10 turns primary and 20 turns secondary could result in a 5 dB stronger signal. Just an idea...

Too many fronts opened here. Just back from Venice EME conference. It was fantastic to meet so many interesting OMs

and to learn so many things. Very interesting presentations on new digital modes. Specially QRA64 which seems will be

a game changer, not in HF but in microwaves EME due to more than 6dB performace over JT4 as is not affected by signal spread

due to moon libration. interesting times ahead ! :-)

I will contact you in a private mail later regarding this stuff.

BTW. Any chance for a LF/MF meeting next year ?? May be in the HamFest 2017 we can get a corner to meet there ??

Where is it?

Almost ready for LF here Stefan. Just need to assemble LPF and PA. Previous test on LF with 100mW were very encouraging

Nice nice. I will be there soon too. Let us try a QRSS-3 QSO soon. But then you will need more power :-)

73, Stefan

 

73 de Luis

EA5DOM

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De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: miércoles, 24 de agosto de 2016 10:34
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: Re: 477 EA5DOM QRP TEST 1 WATT U3

Hi Luis,

Not bad for 100 mW. This was my best spot from you last night:

Timestamp	Call	MHz	SNR	Drift	Grid	Pwr	Reporter	RGrid	km	az
2016-08-24 03:24	EA5DOM	0.475784	-20	0	IM98wn	0.1	DK7FC/P	JN49ik	1398	27

I will be on air again too, soon.

BTW what about LF on your side? I like to come back soon and will test a transductor instead of a variometer. So i will start with a small coil that can take just 5A or so. But that is fine for the test.

73, Stefan



Am 23.08.2016 23:25, schrieb VIGILANT Luis Fernández:

Hi MF

Real power from U3 to antena is 100mW

So far just one decode in WSPR from G8HUH. Band is in good conditions 

73 de Luis

EA5DOM