FOUNDATION COURSE DATES ANNOUNCED

The dates for the next RADARC foundation course are June 22nd 2019 and July 6th 2019. Please note these are not consecutive Saturdays due to room availability.

If you are interested and have not already contacted us please see details on the web page training section and use the contact form there.

If you are already licenced and could maybe spare some time to help Ray with the course, on either day even for an hour this would be much appreciated.

Operating on QO-100

Heard of QO-100? Also known as Es’hail 2, the first geostationary satellite carrying amateur radio transponders launched from Kennedy Space Center at 20:46 GMT on Thursday, November 15, 2018 and is now in a geostationary orbit at 25.9° East. These are the first amateur radio transponders to be put into geostationary orbit and the satellite footprint covers an area from Brazil to Thailand. The transponders are very wideband indeed, and have been designed to be relatively straightforward to access. Being a wide linear transponder, there’s plenty of room, but also plenty of activity, and the activity is in all sorts of modes, including digital ATV, digital voice, CW and SSB. The downlink is 10GHz and the uplink is 2.4GHz. These frequencies are no coincidence…

Receiving QO-100 is a matter of connecting an inexpensive commercial LNB, like you’d find on the arm of any Sky dish, to a suitable power supply via a bias-T, to an inexpensive SDR connected to your PC, including the RTL USB dongles, or indeed to any wideband multi-mode receiver that covers 7-800MHz. An unused Sky installation could be used pretty much as-is, by simply tweaking the dish to point to a very slightly different point in the sky – 25.9°. Indeed there are reports of QO-100 being heard via Sky dishes while the dish is still aligned on the Sky constellation at 28.2°E. PLL-equipped LNBs are better, but not essential.

Once you have a receiving setup sorted, it’s time to turn your attention to the transmitting side. The uplink is in the 13cm amateur allocation, adjacent to 2.4GHz Wi-Fi. There is a lot of room for creativity here, and lots of options. OE5HSR has pulled together an excellent PDF, which is pretty much a must-read for this topic. You can find this here.

I’m sure that some of our members will be having a go at working this unique satellite, and if you’re one of them, we’d absolutely love to hear from you at one of our show-and-tell evenings, or even better a live demo!

72000km+ SSB QSOs using a couple of watts and some recycled gear? Yes please!

Credit: AMSAT-UK for orbital and footprint information

Mentoring meeting update

From member Min G0JMS:

Following the large number of helpers and stations on last Thursday’s Mentoring Meeting evening and the club net, which was very popular, we are planning to run this evening event again in a simpler format with very local stations or anybody with a mobile HF rig. Reduce the QRM by using different rooms.

It’s reported the local RD repeater was very busy with some newly licensed operators joining in.

Members at the RRFC answered many questions from new operators and the evening was a success with club members helping to put up and strip down the stations. We operated on HF and VHF.

Offers of help would they please contact Min G0JMS

RSGB CommonWEALTH CONTEST

The RSGB Commonwealth Contest runs from 10:00 on Sat 9th March to 10:00 Sun 10th March. You will hear participants calling CQ BERU (British Empire Radio Union). This is a CW contest in which the participants must be in commonwealth countries such as Australia, New Zealand, Canada, Ghana, The Gambia, Grenada to name a few. A full list of Commonwealth Call Areas may be found at https://www.rsgbcc.org/hf/information/codes.shtml. Stations from those areas may also work Headquarter stations including those from their own call area. The contest details may be found at https://www.rsgbcc.org/hf/rules/2019/rberu.shtml.

Bob G3PJT maintains an interesting site at https://berucontest.wordpress.com/ with the latest news about participants, especially those travelling to some far-flung part of the commonwealth. Our own Don G3XTT will be operating as C56DF from The Gambia. I’m sure he would be delighted to work as many RADARC members as possible!

One of the advantages of this contest is that it is easier for UK stations to work DX because you are not competing with most of Europe or the USA. Saturday afternnoon is worth trying for African stations on 20m. You should also be able to work many Canadians on 20m from mid-afternoon to mid-evening, and on 40m during the evening. It’s worth getting up on Sunday morning to operate between about 06:00 and 07:30 as you’re likely to work VK and ZL on 40m and possibly 80m. There’s a very noticeable lift around UK sunrise that coincides with sunset in ZL.

RADARC in RSGB AFS contests

RADARC participated in three RSGB AFS contests in January – CW, Datamodes, and Phone. Each was of 4 hours duration on 40m and 80m. Typically stations started on 40m and as propagation changed, moved to 80m. In all three legs, it was very noticeable that GM stations had much better conditions on 40m than the Gs, and hence GM stations tended to be the winners or runners-up.

AFS CW
RADARC came 6th in the Local Club category with a team consisting of Don G3XTT, David M0DHO, Jim G0LHZ, and Michael M0MPM. I stayed on 40m longer than many, and this helped to reduce the time at the end of the contest whenI had worked everything on 80m. For details, see https://www.rsgbcc.org/cgi-bin/hfresults.pl?Contest=AFS%20Contest%20CW&year=2019.

AFS Data
RADARC came 24th in the Local Club category with a team consisting of David M0DHO, Michael M0MPM, and Simon M0ZSU. This was my first attempt at a datamodes contest and using N1MM and MMVARI to send RTTY and PSK, and I treated this as a learning exercise. For details, see https://www.rsgbcc.org/cgi-bin/hfresults.pl?Contest=AFS%20Contest%20DATA&year=2019.

AFS Phone
RADARC came 14th in the Local Club category with a team consisting of David M0DHO, Jim G0LHZ, Jonathan M0JSX, and Michael M0MPM. Dealing with the inevitable QRM is one of the challenges. Running with 400W meant that I was able to keep my run frequency on each band. For details, see https://www.rsgbcc.org/cgi-bin/hfresults.pl?Contest=AFS%20Contest%20PHONE&year=2019.

meeting 14th February – TELL US WHAT YOU’RE UP TO!

14th Feb Woodford Park meeting is a chance for us to catch up on the
various projects/activities we’re up to – in particular any follow ups
to the Great Construction Contest but not limited to that.

If you’d like a short (5 minute or so) slot let me know.

Doesn’t have to be stuff – could be contest updates or how RADARC
contributes comms to events like 3 towers etc.

Also – what would you like to see and I’ll try and arrange?

We can take contributions on the fly on the evening if need be.

  • Min G0JMS will kindly bring along a RigExpert HF to VHF SWR meter (Digital display) RigExpert to show you and VHF to UHF swr power meter (Cheap unit) which includes frequency. He will also do a brief demo of Yaesu Fusion – Wires X technology RF paths permitting.

If necessary, I’ll bore you for a few minutes before the bottles and
tomatoes start flying:

  • Geostationary satellite project – es hail 2. Mike G4CDF (and possibly others???) is making the running on this one but I will present on his behalf a very short overview. iirc it’s 2.4GHz up and 10GHz down. tx/rx is based on an SDR transceiver (lime sdr mini).
  • Adventures with FT8 internals and taxi radios (generating FT8 tones by pulling a carrier around) – update. TBH anything that generates a stable carrier and can be pulled a bit maybe down to 1Hz resolution looks like it might work – eg. voltage controlled oscillator.
  • cheap RTL-SDR dongles (£15 delivered). Mine does work but probably better to get the real ones rather than fakes like mine.
  • short gnuradio demo (maybe)

We’ll have the ICOM IC7300 out for people to have a play with and the spectrum analyser.

Tea, coffee and biscuits will be in plentiful supply all evening.

Looking forward to hearing from you.

73

John

G4RDC

Apollo Experience Report – Lunar Module Communications System

A fascinating document from the Apollo programme was recently unearthed on the NASA website by a local amateur, Jim M0YOJ. It goes into loads of detail about the development and use of RF systems on board the various vehicles involved the lunar programme. For some light bedtime reading, the full document is here. Thanks Jim (and John!) for highlighting this.

The development of the lunar module communications system is traced from ‘the initial concept to the operational system used on manned lunar missions. Included are the problems encountered during the development, the corrective actions taken, and recommendations for similar equipment in future programs. The system was designed to provide communications between the lunar module and the Manned Space Flight Network, between the lunar module and the command and service module, and between the lunar module and the extravehicular crewmen. The system provided the equipment necessary for voice, telemetry, and television communications; ranging information; and various communications links.

Website for the Reading And District Amateur Radio Club