Posts by G4KLX

I have a HackRF (and LimeSDR, and a Pluto) but decided to go the more conventional route of an FT-817 and SG-Labs equipment for TX. RX is via an RTL-SDR,only for space reasons.

Take a look at https://www.qrz.com/lookup/DL9SW

I appreciate this link. I tried to join the official forum but never received an email (I am not alone) and so was never able to get the software officially.

Could you give more information on the bridge that you are using please?

I want to make RL measurements on my POTY and that looks like a very nice way to do it.

Jonathan

I believe the US licence states that encryption is not allowed, except by ground stations controlling amateur satellites. I would guess that our licence is rather lenient compared with others. Can you imagine any other licence using the phrase "from time to time" for the time interval for testing the stations transmitters?

I don't want to start a flame war, but you are incorrect on many counts. Tier 2 is used by everyone, I think you mean tier 3.

The MMDVM does not include a vocoder chip and uses no proprietary technology. It is all open source of course. All of the protocols used are fully documented and can be found on the Internet, although P25 takes some finding.

I must take issue with that. All of the digital voice modes are fully documented, as they have to be so they don't appear as "codes or ciphers" to quote the UK licence. I wouldn't have been able to create the MMDVM otherwise.

I have some slides from their talk at Hamcation. The transport layer is DVB-S2 but being used for data/voice rather than video. It includes access control and other non ham friendly technologies, not to mention the large amount of technology needing to be flown on a satellite in a radiation unfriendly environment.

It is probably tied in with it being for use by FEMA also, in which case I don't think it deserves to be called phase-4B or be within our bands. That's my opinion anyway.

They also did a presentation on QO-100 before phase-4B which mis-characterised our beautiful satellite in many ways, although that was through ignorance I think.

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What happens if I create a proprietary modulation on our next satellite and only when you buy the modem chip from AMSAT you can access it? Sounds like a business model

That sounds like what is being proposed for Phase-4B by the Open Research Institute in the US. It's truly scary that this sort of thinking is seeping into our bands.

Excellent, thank you. Reading those will be like meeting old friends.

The question becomes: does anyone have the documentation released about the PACSAT protocols? If so, then I think an implementation would not be difficult, I don't remember the client side being overly complex. Therefore the corresponding server side would not be either.

I (re)wrote a client suite for the PACSAT protocol back around 1994 in C, based on the work by John G0ORX. It did rely on the Linux kernel AX.25 support (which I had a connection to) for the connected mode uplink, downlink would be trivial in comparison. It is available as source code from ftp://ftp.amsat.org/amsat/software/Linux/ with the filename of microsat-0.9-Xaw.tar.gz.

I don't see that there is any issue with operating full duplex in any mode that is allowed by the bandplan. I operated full duplex occasionally on SSB on AO-13 and AO-40. The only difference is that this is being done with FreeDV. I think QO-100 is a great way of advancing the hobby with experimentation and it should be encouraged.

Very similar to my AO-13 mode B/L/S system. I also had a TS-670S as a 10m IF radio. See AO-13 mode L with a TS-711 and TS-811

I did my AO-40 operation from HB9 land (as HB9DRD) with various combinations of IC-910H, TS-700G and an IC-PCR1000 for beacon decoding while talking.

Happy days!

At Ham-Radio, the dishes used by AMSAT-DL had rather nice stickers on them. They said “AMSAT-DL P4-A QO-100” and the AMDAT-DL logo.

I see that the shop sells branded mugs and pens, how about selling those stickers or something similar for us to put onto our dishes and equipment racks?

The way I got my azimuth correct was to use the Sun. I worked out for a period of a few days when the Sun would be the same azimuth as the satellite and used that time to ensure that the shadows of the feed were in line with the rest of the dish. Then I only had one degree of freedom to worry about.

If you have already received Astra 19E and BADR then you will know the elevation calibration offset, so use that information to set the correct elevation of the dish beforehand.

Once you have the system on the correct frequency for the NB transponder, I found aligning the dish to be easy, it is a string signal even with some off pointing.

They had a full set of prototypes at Ham Radio in June. They also have a TX upconverter for narrowband use.

Perhaps it should be measured in dB relative to the beacon, with positive values not allowed?

That was an excellent dinner, and it was fantastic to be able to chat with people like Achim DH2VA in a more relaxed manner than was possible at the AMSAT-DL stand.

I have two observations though:

1. There were many seats booked but people didn't show up. Would it not make sense to charge a deposit (say €10) to encourage people to follow through with their commitment. Maybe refundable up to 24 hours before the dinner?

2. The prices on the dinner menu were much higher than shown in the standard menu. I think approximately 20% more. I know that restaurants have a service charge for big groups, but that does seem excessive.

I will be there for next year.

1. Yes, I will be on the HamRadio and will participate on the meeting.

2. Yes, if we have the opportunity to have a common dinner I will participate as well.