Showing posts with label aircraft. Show all posts
Showing posts with label aircraft. Show all posts

26 May 2017

Mobile phones on aircraft - NOT amateur radio

So, OFCOM has changed the rules to allow mobile phones on aircraft. I objected. In my view this is stupid idea. Imagine phones ringing all the time on a long flight. People managed in the past.

See http://ofcom.cmail20.com/t/ViewEmail/i/B17ECEB3D452F524/59D1BD3EA2F08127C67FD2F38AC4859C

22 May 2015

6m WSPR update

A few people have noticed that 6m WSPR is quiet when the band is open and there is Es about. This is understandable as working all over Europe is possible with QRP SSB in a decent Es opening. I still hope there will be more DX (USA, Canada, South America, Africa, Caribbean, etc) on 6m WSPR this spring/summer. It requires people to stick with the 6m band and the WSPR mode.

Today on 6m my best DX (spots exchanged in both directions) is G4BRK (134km). I suspect this is tropo enhanced by the presence of aircraft in favorable positions. This was certainly the case with G8EPQ earlier. Eddie G3ZJO was tracking where planes would be to give enhancements. No sign of Es today on 6m WSPR, well not so far.

I am pretty sure some paths are only possible when planes are near the path and the reflections off the aircraft result in favorably low Doppler shift. It is quite common to see strong aircraft reflections but no WSPR decodes. I have seen this on both 6m and 2m. There is some drift as my rig goes from TX to RX, so often the Doppler I report is not Doppler, but drift in my rig. With aircraft reflection it is quite common to see multiple reflections with different amounts of Doppler. On some transmissions I have seen up to 6 different signals from a single TX as a result, presumably, of planes in a stack.
6m WSPR unique spots so far today.

11 May 2015

6m WSPR - aircraft reflections?

I am pretty convinced that some of my 6m and 2m WSPR spots are only possible when aircraft are in the right place at the right time with acceptably low Doppler. This evening Eddie G3ZJO was spotted several times with quite high Doppler on occasions. I am not convinced that I am copying Eddie as a result of planes - I think his signal is copied by pure tropo, but I am convinced some signals are only copied as a result of aircraft reflections, much as happens on bands like 23cms upwards. G3WKW (134km) is an example of a station I only seem to copy by aircraft reflection on 6m and 2m.

G3ZJO has analysed M0YOU's signals in his blog. See http://g3zjo-radio.blog.co.uk/2015/05/11/six-meters-aircraft-reflections-20343648/ .

13 Apr 2015

6m - all quiet so far

It is about a day now since I was last spotted by anyone on 6m. I am still active (vertical omni V2000 and 1W ERP) but the level of activity is very low and Es has still to really get going this season on 6m. I am on 6m TX 20% and RX 80%.  I will be on 6m all day and this evening.  So far, a few days ago, I was still only being spotted by G stations by tropo and aircraft reflection.

24 Jun 2014

6m - overnight

Just resync'd the internet clock and will leave WSPR running on 6m overnight looking for very long distance, multi-hop Es (ever hopeful), GDX and near continentals by tropo or aircraft reflections. Just got to hope the software does not stop working on my Win 8.1 machine in the middle of the night!

There is some debate about tropo versus aircraft reflection on 6m. David G0LRD is of the view that most of my 6m WSPR GDX is tropo, whereas I feel it is because of aircraft reflection, but only when the Doppler is low enough. Sometimes you have to wait hours and hours for  this.

I'd much prefer it if these relatively long (for me) GDX paths were pure tropo, but feel the evidence points to aircraft reflections. The debate and evidence gathering continues, HI.

6m WSPR - G0OQK spotted (with Doppler) and CN8LI

For the first time G0OQK (98km) has been on TX so this was my chance to see if reception here was pure tropo or aircraft assisted.

Well, looking at his last traces here I can see 2 or 3 traces in each 2 minute burst suggesting reflection from planes. This is far cleaner than I've seen some stations. I guess it says something about the flight paths.  WSPR seems to  decode the transmission with little Doppler, but there is little doubt that Nick's 2W to a V2000 is helped by aircraft reflection. Of course, being in the Chilterns I wonder if it is reflections from gliders?

This suggests almost all (or all?) 6m GDX signals copied here are aided by aircraft reflection and few/none are traditional tropo. For more local stations most signals are tropo but even over 25km paths people frequently see Doppler from aircraft on my traces. I guess it depends whether the direct path, or aircraft reflected path, dominates? For locals, the direct (tropo) path usually dominates.

UPDATE 1510z:  No 6m Es here so far today and just a couple of spots received  of G0OQK (98km).  I noticed more traces of Nick than proper decodes, either Doppler wrong or MS pings too short.

UPDATE 1516z:  My WSPR software decided to close on its own this afternoon (Win 8.1 issue with updates) so I have resync'd the internet clock and restarted the WSPR software. It is now working OK as G4IKZ is spotting me at 1506z. Seeing 50Hz sidebands on the very strong reports from this Nick. Not sure if it is his issue or mine. Not really worried as it only appears, sometimes, on strong signals.

UPDATE 1532z:  I spoke too soon as CN8LI (2113km) spotted me at 1516z just after I spotted G4FFC (45km). There is Es about today.

22 Jun 2014

6m - CN8LI again and more local DX

The path to CN8LI (2113km) is there again today, but not as strongly as yesterday. So far a single spot in each direction mid-morning. You will recall I use 1W ERP  with a vertical V2000 antenna with about 0dBD gain on 6m. My coax is CB RG58, so quite lossy.

There is quite a bit of inter-G/GDX and aircraft scatter activity with G4FGJ (44km), G4IKZ (18km), G0OQK (98km), G4BRK (134km), G0LRD (25km), G4FFC (45km), G3WKW (134km), G8JNJ/A (184km), as well as ON0VA (280km) with the latter with 3Hz Doppler so almost certainly aircraft reflection.

6m is an interesting band!

4 Jun 2014

Odd start on 6m today

As 0438z OZ7IT (853km) spotted my 1W ERP 6m WSPR signal by very early morning Es I assume. Then, just spots from local G4IKZ (18km) until I spotted G3RCE (185km) a little while ago, presumably by tropo with some aircraft reflection (2Hz Doppler). Interesting that a lot of the local spots by G4IKZ had a fair bit of Doppler too.

29 May 2010

Concorde to fly again?

There are moves afoot to get Concorde, the supersonic jet, flying again on memorial flights and it is possible it may yet fly over London at the 2012 Olympic Games opening. The only time I've been on Concorde was at Duxford Airport in Cambridgeshire in a static display. My wife's brother used to work for BT and fly to the USA and back in a day using Concorde so he could hold meetings in New York on a day trip - how times change!

See http://news.bbc.co.uk/1/hi/world/europe/8712806.stm