31 Mar 2015

Rainbow and churches blog - NOT amateur radio

See http://eachurches.blogspot.co.uk/ .

Today we visited Wilburton St Peter church located some 10-12 miles north of Cambridge.  Parts of this light and airy church date back to the 13th century.

Today was a showery and blustery day.   On the way home we saw a great rainbow, but it soon disappeared.

10m USA WSPR spots of me today

Well yet again, I was totally wrong:  10m did open to the USA this afternoon and quite early too!   AE7YQ (8533km) was the first to spot my 500mW WSPR at 1534z. Since then,  WB2TQE (7097km) has spotted me a few times too.

UPDATE 1948z:   WB2TQE (7097km) was currently the last USA station to spot me on 1806z. So far today just him and AE7YQ have spotted me in the USA. I suspect there will be no further USA posts today.

472kHz WSPR and VLF earth-mode experiments

So I checked that I am regularly synced to internet time - I am - but 472kHz has been very quiet today since breakfast time. The last spot of me was from G3THQ (88km) at 0608z. Overnight WSPR spots were exchanged (both ways) with F1AFJ (607km) in JN06ht square. I should be getting him much better, suggesting my RX system is somewhat deaf!  His ERP is much greater than mine.  I am still using 5mW ERP and my earth-electrode "antenna".
Unique WSPR spots overnight on 472kHz
My new soldering iron is on its way, so I hope to do some VLF earth-mode field tests soon. First job will be to alter the match to my earth-electrodes on my VLF 5W beacon.  Initially, I may try the existing VLF beacon on a dummy load and receiving it in the lounge to test the RX set-up. This will test my preamp and Spectran settings.  It is so long since I have done any VLF work I have almost forgotten what settings I used!

Sunspots and 10m - Tuesday March 31st 2015

Sunspot number has dropped back to 53 and 10m propagation is still "fair". K index is 2.  Based on the last day or so, I do not expect to be spotted in the USA on 10m today. Of course, being 10m, I could be totally wrong! We'll find out later when the afternoon and evening are over. If 10m does open to the USA, which seems unlikely based on conditions on the band this morning, I doubt my 500mW WSPR would be copied over there much before our teatime, i.e. after 1600z at least, or even later.

10m WSPR - quiet morning

This morning on 10m WSPR has been very quiet with just local G4IKZ (18km) and EA8BVP (2986km) spotting my 500mW WSPR beacon. No "DX" DX as such at all.   Not even spots from Eastern Europe or Israel. Conditions must be changing.

30 Mar 2015

472kHz - lack of WSPR spots?

I was beginning to wonder why I was not getting spots on 472kHz WSPR.   At first, I thought it was just down to too few stations in range, until I noticed a "peer unreachable" message, so I was not synced to internet time, at least recently.   Having changed my internet time server and re-synced, I am now being spotted weakly by G3THQ (88km). The band does seem quiet though with very few UK stations active on 472kHz this evening. Perhaps those stations who are active are using different weak signal modes like OPERA?

The future of HF broadcasters

Deutsche Welle (DW) is closing its last relay station, which is in Kigali, Rwanda. In recent years DW like many shortwave broadcasters, has been facing financial cutbacks. Also there are far fewer broadcasters using shortwaves these days.

As a youngster in the 1960s, I recall shortwaves crowded with AM broadcast stations, many from all over the world transmitting in English, with their distinctive interval signals. There was a magic about shortwave broadcasting back then. Quite a few could be copied with very simple receivers too. There is something quite nostalgic about listening again to those long-gone interval signals from behind the Iron Curtain. I remember getting some excellent freebees from China back in the early 1980s. Of course, it was all to spread the propaganda.  All I really wanted was their QSL card!

These days, users are often reached using the internet. Of course, it begs the question, "who is now filling the empty, vacated channels?"  In the long run amateur radio might gain some allocations, although the noise floor on HF is increasing too. SMPUs, cable TV and numerous other sources are mainly to blame.

See http://www.dw.de/deutsche-welle-closes-kigali-outpost/a-18340960.

Pixie Files

My assembled 40m Pixie
The Pixie is a very simple HF transceiver. Usual power out is in the 200-1000mW region, depending on band and DC power source.  It was first developed some years ago but the basic concept is using a PA transistor as a mixer in a simple direct-conversion receiver. On TX this is used as the TX PA.

Being simple, it has a number of limitations but it certainly works. A major issue can be AM broadcast breakthrough, although my 40m version is perfectly usable. I was very impressed with my little kit that came with all parts including a silk-screened PCB, all sockets and a crystal. It needed low-Z Walkman type headphones, a morse key and battery - that was all. On 40m the sensitivity is pretty good with 0.5uV clearly audible and my RF power out is around 400mW. A lack of both RF and AF RX selectivity is also noticeable.

Kits are available from several sources at prices that are hard to beat. I recently bought a kit for $10 with free airmail from China. It is available for less than half this price I subsequently found out. Unbelievable for a fully functional HF transceiver. Of course, being so simple you may prefer just to build it dead-bug fashion. I bought a kit as I wanted to see how my building skills were.

As a mature design, it has been through several iterations, some improve the basic design, but most do so at the expense of increased complexity. You'd be hard pressed to find a circuit for a complete HF CW transceiver much simpler.

See www.gqrp.com/The_Sprat_Pixie_File.pdf .

10m, 630m and 2200m WSPR

My little WSPR-AXE-CW beacon has been on 10m about 30 minutes. So far just G4IKZ (18km) spotting me but it is very early still. We are now approaching the Es season so there should soon be lots of Europeans on the band.

No new 472kHz stations overnight.

UPDATE 1026z:  Just G4IKZ so far today with zero DX on 10m o far. A disappointing morning so far on 10m WSPR. Of course, things may improve but the absence of even stations on the edge of Europe suggests a USA opening today is less probable.

UPDATE 1032z:   Only G3THQ (88km) spotting me on 472kHz WSPR and this was hours ago. All very quiet. I think there are fewer stations active on this band and mode than before? This certainly seems to be the case in daytime.

UPDATE 1325z:  Only 1 spot from EA8BVP (2986km) on 10m WSPR all day apart from local G4IKZ. So far a totally dismal day on 10m WSPR!

UPDATE 1800z:   Several spots from EA8BVP (2986km) but still no spots at all from the USA. Conditions across the Atlantic seem far worse now than a few months ago.

Maybe I need to try a new band? I fancy trying 136kHz (2200m) WSPR from this QTH as I think my earth electrode will be more efficient (bigger "loop in the ground") as I go lower in frequency. My best 136kHz WSPR DX from the old QTH was 250km. Some locals and semi-locals might copy me on 136kHz WSPR, although activity is very low on this lower band in the UK. I think some skeds would be needed.

Sunspots and 10m - Mon March 30th 2015

Sunspot number has dropped to 73 and 10m is again expected to be "fair". With k=2 I guess we may see some 10m WSPR spots from the USA later.