22 May 2014

SmartMic

See http://www.rowetel.com/blog/?p=3125 .

This could be a killer app for amateur radio: Digital Voice (DV) without the need for a PC. It consists of a board that goes between the mic and rig and the rig and LS.

DV in the end is a 1.25kHz wide 16QPSK signal able to work with very low S/N ratios and low power transmitters.

CN8LI - 6m

Reports from CN8LI have been coming in consistently all afternoon. I assume the propagation is Es but this very non-sporadic! I suppose it is just conceivably single hop F-layer, but I think Es is more probable. Now if only someone another 1000-2000km further south was on too so multi-hop Es into Africa was a possibility. Later in the Es season, multi-hop Es becomes more likely into S.America, the Caribbean and N.America.

At 1806z CN8LI is still spotting me well (-1dB S/N).

UPDATE 2125z: CN8LI's last 6m spot of me was at 1854z (+6dB S/N) and this appears to be the last today. Just G4IKZ spotting me now, lot of times!

UPDATE 2200z:  finally closed down at  2145z with just G4IKZ spotting me all evening.

Clearing the back of the (old) garage

As I was in hospital Sept-Jan because of my stroke, I was not around when my wife arranged for our old home to be rented out. We left a lot of my stuff locked away at the back of the garage and only cleared this today. Among the "goodies" were 2 QRP power meters, a DC PSU, a small rotator and several antennas. I had wondered where these all were! Now I know.

Very quiet start on 6m this morning - better later

This morning, it was very quiet start on 6m WSPR with just the usual strong spots from G4IKZ (18km).  I am actually very pleased with these reports of my 1W ERP signal as I am pretty sure Nick uses a horizontal beam so we are cross-polarised.
Sunspot count is 100 but 20-30MHz conditions are reported as being "good" so maybe 10m will be in decent shape for DX today. 6m will remain "sporadic" hopefully with some Es propagation later?

UPDATE 0940z:  Still just G4IKZ spots this morning so far.  Not sure if the few dB variation in reports is the noise floor increasing, path variations, or Nick moving the antenna a tad.

UPDATE 1445z: Well, there is 6m Es about.  Firstly OE1MSB (1220km) at 1114z then several spots from CN8LI (2113km) - 14 spots to 1444z - as well as G4FFC (45km) although at 45km hardly GDX. Wouldn't it be great to hook up to some TEP with Es to northern latitudes? Lots of Doppler on my spots from CN8LI - moving Es patches?

UPDATE 1530z:  Had to disconnect antennas because of local storms.

UPDATE 1635z:  Antennas back on around 1625z and CN8LI still spotting me and me him. He has been a remarkably consistent reporter all afternoon long. At teatime signals both ways are VERY strong (like he is down the road!).

UPDATE 1740z:   HB9PLH just spotted me on 6m WSPR. Still plenty of Es around.

21 May 2014

6m Es and GDX

Well 6m "came good" today with Es to  IK1WVQ and CN8LI as well as GDX in the form of G8JNJ/A (184km) G4FFC (45km) and G4BRK (134km).  I get the feeling that daily Es is now more likely until later in the summer. Tonight I shall have to go QRT as we have thunder forecast, so I need to disconnect antennas. Today has been a good day on 6m.

It is interesting to see just how much variation there is on Es signals.  For example, my 1W ERP signal level with CN8LI varied by 27dB over lunchtime. Strongest was 0dB S/N and the weakest -27dB S/N.

G8JNJ/A on 6m WSPR

All very quiet on 6m so far today apart from the usual G4IKZ (18km)  spots. Then at 0914z G8JNJ/A in IO90hx (184km) spots me weakly at -29dB S/N. No Doppler, so aircraft reflection less likely, so presumably tropo?

Sunspot count 126 and 20-30MHz forecast to be "normal" again, so 10m propagation is, again, anyone's guess. Still waiting for first Es openings today on 6m.

20 May 2014

Mark Thomas (Channel 4) Secret Map Of Britain

Maybe, like me, you had not seen this YouTube video before. Mark explores some of the places left off some UK maps to preserve their secrecy. In many cases the information is readily available by other means. Apparently the number of places left off maps runs into thousands (at the time the film was made) and yet many places which you might expect to be hidden are not. Bizarre.

At one time Devonport Docks (Plymouth) were blanked out from 1:25000 scale OS maps. Not sure if this is still so. Looking at the map it was very obvious this was a secret place and no doubt a prime Russian target back in the Cold War.  Blanking out the area drew attention to it - the reverse of the intention. Doh!

I make no judgments, just sharing an interesting YouTube link.  I assume sharing this publicly available YouTube video does not contravene any state secrets. Mark filmed this for Channel 4 TV here in the UK.

Yaesu and that (never coming) FT817 replacement

Yaesu amaze me. They would have a near certain HUGE market for a more up-to-date version of the FT817. We punters have been waiting YEARS and it has still not appeared.

Instead they mess about with VHF/UHF digital radios. They could probably re-use the FT817 mechanics and just update the insides. The FT817 is a good radio, but it is 14 years old and there are many features it could do with. The FT817 and FT817ND must have sold over 500000 worldwide! The window for releasing a new version is rapidly closing as the sunspots fade.

My wishlist (just some features, no particular order)
  • LiIon battery pack
  • Auto ATU
  • Speech processor
  • OLED display
  • DSP noise reduction 
  • 70MHz
  • 1296MHz
None of these should be hard (or expensive) for Yaesu to develop. So just why have they not done this?


6m - Tuesday May 20th - some lunchtime Es

A very uneventful morning so far on 6m WSPR with just the usual strong reports from Nick G4IKZ (18km) on the far side of Cambridge. No Es yet, although it is early in the day. At  the moment, 6m is very slow going with LOTS of WSPRing during the day for (maybe) a fleeting opening. At least with WSPR you can do something else whilst monitoring and TXing.

Maybe the 6m band will open up later?  Sunspot count is 130 and 20-30MHz forecast to be "normal". Again, 10m propagation will be whatever. 6m will remain "sporadic" with lots of white noise. It would be good to hit a period of 6m Es that lasts all day. It is early in the season I guess. On 6m I'd be very lucky to see any real long distance DX.


UPDATE 1435z: Well patiently 6m WSPRing paid off with spots from Morocco by CN8LI (2113km) late lunchtime today (best -5dB S/N at 1404z).  With that report, he would have copied me if my ERP was just a few mW, given a quiet RX environment his end.  This is a problem nowadays: often the RX noise floor can be quite bad, especially in towns and cities with so much RF noise pollution.   CN8LI was also spotting me (more weakly) at teatime (1612z) - see table above. 1W ERP seems plenty for Es.

UPDATE 1930z: No further Es in evidence here since CN8LI at 1612z. Think that is it for today?

19 May 2014

East Cambs 2m Net

Every Monday evening at 8pm UK time there is a net on 144.575MHz (note 144.575MHz , NOT 145.575MHz) FM in East Cambridgeshire. The net started some years ago as an AM net on 144.55MHz but one joiner had no AM, so we went over to FM, vertically polarised.  Usually there are 3-4 people on the net and others are very welcome. Discussions are wide ranging and cover all sorts of amateur radio subjects.  Usually one person has a query and the others try to answer the question. Occasionally we do on-air experiments too. We always finish by 9pm latest and quite often earlier if we run out of topics.