29MHz trans Atlantic DX...

[radiogareth]

I have been using a Slim Jim for 10m, built from 450 ohm slotted ribbon cable. They can be a bit quirky to get right, as this article mentions.
http://www.infotechcomms.co.uk/download ... im_Jim.pdf
Its also worth adding a coaxial choke just underneath the base. Expect some 'experimentation' i.e. start long, then get shorter.
Although omni-directional, they do work well and with the re-appearance of the 10FM US repeaters most afternoons, the old adage 'if you can hear it you can work it (with 100W)' seems to stand.
It works for me....
Gareth

[M0DTS]

The band is full!

This was Gareth, Myself and Mike all Transmitting at the same time 29.150, 29.175,29.200 received on the Pennysylvania sdr.
Lots of multipath so no decodes right now, poorer conditions today and the band has opened up much later.

Rob

[K0ZAK]

Here are the 3 signals in Baltimore fiding up and down. none giving enough MER to decode today

[g0mjw]

I had better upload this.

DVBT_Transverter.pdf

(141.94 KiB) Downloaded 491 times

[HB9DUG]

Dear All,

I have asked Edouard F4EXB to look at adding an option for a 20 kS/s sample rate (20250 S/s actually) as for now,the kiwiSDR plugin assumes always a 12 kS/s rate.

I will keep you posted of the status of my request.

73 qro de michel, hb9dug

[G3YKI]

Something very curious strikes me about Rob's picture of three DATV signals. The outer two have very frequency selective fading, with two or three notches drifting up and down across the response. The centre one is quite different as it has almost exclusively "flat" fading with the whole band going up and down together. So, two very different channel characteristics at the same time, same band, and you would have thought very similar paths.
Can anyone explain that?
Ken

[radiogareth]

I can't explain but am fascinated by it all. I'm in SE London, Mike is near Harwell/Didcot and Rob is in North Yorkshire. They both have horizontal beams, I have a vertical.
Gareth.

[g0mjw]

Gareth and I are not all that far apart, both in IO91 I think, whereas Rob is IO94 so much further North. We are all approximately the same longitude so I think it is the North-South difference. I was on 29.200, Rob was on 29.175 and Gareth was on 29.150.

Mike

[HB9DUG]

Dear All,

I have reconfigured the KiwiSDR: http://sdrhf-fro.iapc.ch:2174 for 20 kS/s .

Unfortunately, the last user of the station has forgotten to switch back the antenna to the KiwiSDR... The issue will be fixed by the middle of the coming week.

73 qro de michel, hb9dug

[G8JNJ]

Hi All,

I have also changed one of my KiWi's located in Dorset to have 20KHz I/Q bandwidth.

http://wessex.zapto.org:8073

This site is still under development, so it's not been made fully public yet, but please let me know if you have any success with it.

WRT SDRangel

I asked the developer a few questions, to which he responded.

"Regarding low rate DVB-S2 I have experience only with QO-100 transmissions and wasn't successful to decode anything below 125 kS/s with the DATV demod. For low rates people would use dense modulations like APSK16 or APSK32 so I don't know if this is due to the low rate or the modulation. I have not investigated further. I also noticed that higher rates will synchronize faster than lower rates. This is already significant between 500 kS/s and 333 kS/s. The DATV demod uses the Lean-DVB software which is a bit difficult to decipher.

I just committed the fix for KiwiSDR variable rates on the master branch. It will use any rate specified in the "audio_rate" message."

Regards,

Martin - G8JNJ