Re: LF: EA in LF NOW !

[Markus Vester <markusvester@aol.com>]

Plenty of good opds detections again here last night: https://dl.dropboxusercontent.com/u/26404526/opds.htm

 

Moving the zoomed section of the spectrogram to your QRG shows a good and narrow (albeit slightly drifting) central carrier. This means that your version of the U3 is keying coherently with continuous carrier phase, helping opds to reach it's full sensitivity. According to earlier observations on MF, there also other Ultimate versions out there which apparently reset the DDS during the gaps, producing random-phase symbols with no continuous carrier.

Best 73,

Markus (DF6NM)

-----Ursprüngliche Mitteilung----- 
Von: VIGILANT Luis Fernán   dez <luis@vigilant.es>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Do, 14 Apr 2016 12:24 pm
Betreff: LF: EA in LF NOW !

Hi LF

 

Thank you all ! This band is amazing :-)

 

Great dynamic reports Markus. You are now my ODX at 1500 Km !

 

>>Eeehm, and what did you run last night? Don't tell me it was just the nacked U3 with, what, 100 mW TX power?

Well, I know it is HARD TO BELIEVE, but that's it. Absolutely. U3 (old, not S) using an ICL7667, not the BS170's which would provide more power

In fact, i'm only using half the ICL7667 powered at 5V. This is good enought to driver the MF PA and do not cause thermal drift in the DDS

 

Antenna height is the key. The 80m building tower is part of the antenna, so it works as a top coil feeded, top capacitive loaded 90m vertical antenna

The radiation angle must be also quite low, which is another interesting factor. Now I'm completely sure I bought the right house for a Ham point of view ! ;-)

 

Let's keep the system running a few more days. Still working in daylight in Opera32. There is time to test other modes too

 

Then the next issue (appart of PA) will be a switching system to be able to alternate Tx periods in MF and LF. Think it will be doable using small power

and vacuum relays. It's a pity to be forced to choose to Tx in only one band

 

73 de Luis

EA5DOM

---

De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: jueves, 14 de abril de 2016 11:39
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: EA in LF soon

Hi Luis,

My congrats again!

Am 14.04.2016 08:45, schrieb VIGILANT Luis Fernández:

Looks very promising. Let's see what happen when using an small PA

Eeehm, and what did you run last night? Don't tell me it was just the nacked U3 with, what, 100 mW TX power?

And what about WSPR-15 ? It would be nice to see you there too. I find the SNR information more informative in WSPR-15 :-)

73, Stefan

PS: Time to leave traces over the pond i would say, when you have the PA ready. 6000 km on LF is much easier then 6000 km on MF!

Will keep it running during daylight also

73 de Luis

EA5DOM