Posts by G0MJW

Interesting. Keep it up.

There are no signals at the image frequency. Things would be a lot worse if there were. One should be able to estimate G/T with a known amplitude signal compared to the noise floor where there are no signals. I only see a 10 dB lift between the NB transponder noise floor and adjacent noise. It ought to be more but my system is not optimised. If I knew the power density of the transponder noise floor I could work out my G/T. This can be done for all antennas that can make this measurement. One can also do this with a beacon of known power but none of the QO100 beacons have constant amplitude which makes things difficult. Perhaps Bochum can tell us what the transponder noise floor power actually is?

Mike

Maybe you have a switch or router in your network that is not forwarding the multicast?

I have two of these PA boards - I am thinking about trying it out but I need a copper heat spreader making. Has anyone done this or could supply one?

Quote from DD4YR

Hello,

in order to be able to better assess the efficiency of the DVB-S2 signal, it would be interesting to anaylyze the division of the packets into video, audio and also 0-packets in the received signal.

How can you measure that? Is there a corresponding analysis software for the MiniTioune available?

73

Robert

Display More

The latest Pluto firmware does this - otherwise TS reader is good.

There was me thinking I could track Felix.

I think it depends on if the coding is encryption - that's not allowed, but certainly proprietary speech codecs are used.

The lens has (or should have) no impact on 2.4 GHz. It's only used on 10 GHz to narrow the beam pattern to better match the dish.

I think it's related to the chip having different options which are expanded out in the LimeUSB but not in the LimeMini but do still exist.

All the beacons are fairly strong. We should use the minimum power to facilitate a QSO, not to be 59+

Mike

Import does not work with the radio running - at least it did not for me.

Ah - So you mean this beacon is from AMSAT, not an allocation to put beacons in. I miss-understood. Lets hope it is something more interesting that 400 baud BPSK.

It is a pity we can't accommodate signals that are a little more than 2.7 kHz wide but I guess the transponder is short on bandwidth and there are rarely gaps between QSOs.

With my deaf Pluto the transponder noise floor is reduced, but it's also not flat. This is nothing new but if you have a weaker station keep away from the edge, you might fall off.

Are there any restrictions on the experimental section? E.g. bandwidth, signal level, length of transmission? I realise it is only 5kHz wide but we can't all use all of it all of the time - or maybe we can with some modes.

You might want to initiate some sort of competition - e.g. who can receive the lowest power signal (CW from Bochum for example) or perhaps most accurately measure a frequency or collaborate to work out the location of a signal like a fox hunt- or perhaps set up some topical e.g. nets Amplifiers, Antennas, Receivers, DX, the ailments of old age,

Yes - it's more than enough bandwidth now for me to send HD DATV! (Humour alert) - it's very good to see the greater bandwidth.

Mike

Quote from PA3FYM

I reckon more than 1700 POTY's (kits) have been made. So there is potential activity enough. Furthermore there must be an RF incentive (i.e. make stuff for 2.4 GHz narrow band) to become active on the NB transponder. Making stuff for 2.4 GHz uplink seperates boys from men ; -)

Don't forget to include the girls.

I agree with Peter.

Mike

Unfortunately the CW beacon SNR is not a very good test because with a large dish you are mostly going to see the transponder noise floor. The SNR is dominated by the uplink signal to noise ratio for big dishes, you could use Bochum and not see much improvement. A much better test to aid in optimising your setup is to measure the height of the transponder noise floor above the background noise floor. Maximising this should result in the best performance. The Wideband beacon MER is a much more sensitive test but even then once you get above 10 dB improvements are very small. Of course, if you are seeing the transponder noise floor at a good level it could be argued there is little point in optimising further. Better to use the time by getting on the air.

Mike

That's very strange. I suggest you stick with the version that works for you and meanwhile speak to Evariste. There were several hardware revisions of the Pluto, mine is an earlier one, later ones had more memory. I am assuming you did the second CPU enable mod. You must have the latest drivers as well but I think you said you did. Your setup seems identical to mine - try it via USB in case your Ethernet adaptor is different?

Mike

Well it works for me. Things to check are how you connect. Perhaps do a search for the Pluto again. Make sure you have the latest IIO drivers installed etc. Make sure it's a recent version of SDRConsole. I could not get the Pluto to run on a PC that had not been updated in a while until I reloaded the Analog drivers.

Proof - if needed.

What might be different is I am accessing it via Ethernet rather than USB, but this should not matter.

Worked fine for me.

The old version of the Portsdown used to do this - it was called digithin. The new version can be configured to do it quite easily with a limesdr. It's also now capable of DVB-S2 which is a much better option. The transmission could be gated by an external signal. The new portsdown is based on a raspberry PI and includes a H264 encoder. You can feed in analog video via a USB dongle but the quality of analog TV is very poor compared to digital so you may want to use a different solution using HDMI video. There is a small box from China that will provide H264/5 encoding that can be sent as DATV using a Pluto or the Portsdown. All can be made to automagically transmit on power up.