DT puzzle

As you may recall, I use (very successfully) on 10m a WSPR-AXE-CW beacon by W5OLF.  In the last 6 months this has served me well.  However I was puzzled by a second report last night that both DT was way out (around 4.7) and the frequency was sometimes outside of the lower end of the WSPR sub-band. I decided to check DT locally using my FT817/PC as a receiver. Sure enough, DT was very high. Setting the clock to internet time -4 seconds made almost no difference. This evening I set my beacon TX frequency about 150Hz higher (adjusted the multi-turn pot) and, for reasons I do not understand, my DT has dropped to - 1.4 setting to internet time exactly on an even minute. It seems resetting the frequency has also fixed the DT issue. Perhaps this is something to do with Wolf's software? Anyway, I am now waiting for local Nick G4IKZ to confirm my DT findings.

UPDATE 2216z:  For reasons I do not claim to understand, I needed a long hard reset (mains power off for 20 secs) to get modulation to appear after a small frequency adjustment. All seems to be working now but the beacon will be on overnight to see if the modulation remains on.

Sunspots and 10m - Thursday May 28th 2015

Sunspot number has dropped like a stone to just 24 (K=1) and 10m propagation is "poor". No F2 DX seen today.  Only Es seen here has livened up the 10m band.

Birthday - NOT amateur radio

A few days ago, one of our grandchildren was 4. Here she is with her dad and her brother opening her present from us in our back garden this afternoon.

Back on 6m WSPR

The "Kent" grandchildren have returned home, so I have my shack back. The "London" grandchildren are due soon.

As well as my 10m 500mW WSPR beacon, I have now returned to 20% TX on 6m WSPR since 1052z. The very first TX burst resulted in 3 spots by G stations with best DX 114km from G4AYT in Kent. The double spot by G3ZJO is interesting. I don't think it is my end, so it suggests a direct path (tropo) and one off aircraft with suitably low Doppler? I'd need to see the trace received by Eddie to be sure, but that is what it looks like.

Initial results on 6m WSPR this morning

UPDATE 1112z:  No 6m Es seen yet.

UPDATE 1844z:   EA117URE (1177km) - SWL or special call? -  was spotting me by Es at 1742 this evening on 6m WSPR.

Sunspots and 10m - Wed May 27th 2015

Sunspot number has fallen to 48 today (K=1), lower than recent weeks, and 10m is again forecast to be "poor".  Es may, of course, liven up 10m and 6m.

UPDATE  1042z:  OE6PWD (1232km) and IZ6QZB (1475km) recently spotted my 500mW WSPR beacon on 10m Es.

UPDATE 2006z:  According to local G4IKZ my dT (ever after a spot-on resync to internet time) is way off (greater than 4 seconds off) . I sync to internet time every 5 minutes on 6m and use this clock to sync my WSPR-AXE-CW beacon, normally once a day.  I'd be interested to know the dT that others measure on my 10m signal.

Early 10m Es

As early as 0550z my 500mW 10m WSPR was being spotted in Italy. This is very early for Es. I shall get back on 6m WSPR later.

VLF upconverter

VLF upconverter

Some years ago I was looking for a simpłe VLF up-converter (to receive SAQ) and came up with the simple circuit shown in the link. This was later improved by HB9DAO. The improved design is also shown.

If you want a simple introduction to VLF or LF listening these circuits may give you some ideas. 

It would not be suitable for serious amateur VLF use over any distance when high dynamic range, long integration periods, and very narrow bandwidths are pretty essential.  It is ideal for reception of commercial VLF signals and time standard transmissions.

See https://sites.google.com/view/g3xbm4/home/vlf/vlf-converter .

Cranial Osteopathy for Stroke - NOT amateur radio

I still have several stroke related issues (feel drunk when walking, tire easily, poor thin liquid swallow, poor voice), so today I started a series of cranial osteopathy sessions with someone recommended to me in Cambridge. The first session went well and I have fixed up a couple more sessions.  Some people swear that this works, whereas others say it is "quack medicine".  I go open-minded.

Time will tell if these sessions help with my symptoms. Although I am improving, the pace has slowed considerably so I am game to try anything that may help. After all this time I still do not feel right. I just want to get my old self back!

Back on 6m WSPR tomorrow

As our "Kent" grandchildren return home tomorrow and our "London" grandchildren arrive until Saturday, I should be back on 6m WSPR tomorrow. I get my shack back tomorrow as our "London" grandchildren are old enough for beds. This means that from around lunchtime I shall be active on both 10m and 6m WSPR.

UPDATE 1818z:   10m WSPR has been quiet today.  EA8BVP (2986km) has spotted me several times again by F2 and DK6UG (633km) by Es, but otherwise just locals. So far, at least, a very quiet day on 10m. As yet, on WSPR this has been a subdued season on both 6m and 10m. I don't think I've missed much on 6m these last few days.

Sunspots and 10m propagation - Tues May 26th 2015

Sunspot number is little changed at 66 (K=1) and 10m propagation is again expected to be "poor".

Apart from locals G4IKZ and G4KPX only early F2 spots from EA8BVP (2986km). No, what I would call , "real" DX  yet on 10m despite the undisturbed conditions. No Es seen here on 10m. I am not currently on 6m as I cannot access the shack PC easily.

10m BitX transceiver

I notice that someone has created a 10m (28MHz) version of the BitX transceiver. Yes, all would like more details but we don't know who you are!

Anonymous said:  "I have successfully designed and built a 28MHz version of the BITX transceiver. The main reason for this project was to drive homebrew transverters for 6, 4 and 2Metres. Contact me if you would like details."

Fourbox transceiver

G7CKF's Fourbox

Jenny, G7CKF  has now taken the 2m Fredbox design and created a 4m version called the "Fourbox".

Hi Roger,

    I feel I should drop you a line with my thanks and the link below, I've used your QRP AM transceivers as the basis for a 4M transceiver and published it on my blog. I've come back to amateur radio after a 20 year absence and since construction was always my main interest in the hobby I reached for the soldering iron.
http://thekeywordgeek.blogspot.co.uk/2015/05/a-transceiver-for-not-lot.html
There is no sparkling new insight to be had from it as it's pretty much your fredbox with slightly bigger coils. There is no crystal because I am cheating and using a Raspberry Pi clock generator to make my 70.260MHz.
My QTH is IO91lw, between Bicester and Buckingham and rather low lying. Very little 4M activity hereabouts, sadly, so the chances of my actually working anyone with it are slim. But that's not really the point of building, is it.
Anyway, hope you find it of interest, and thanks again for sharing your designs.

Jenny, G7CKF

Optical communications over the horizon

I have been too unwell to do this recently, but not long before my brain bleed (Sept 2013) I was amazed at optical communications over the horizon, non line of sight (NLOS) using clear air scattering.

The inspiration for all my optical experiments came from Stuart Wisher G8CYW who did a great series in RadCom a few years ago.

Testing optics

My home made transmitter only consumed about 0.7W from a red LED bought on the internet. My homemade RX and TX used homemade optics based around cheap drain pipes and cheap magnifying glasses. The whole RX and TX were simple and low cost. Only simple test gear was needed too. It is a bit like microwaves, but easier to build and test.

There was no sign at all of the TX beam in the sky.  All alignment used dead reckoning with some panning at the RX end to find the TX.

Using free PC software and QRSS3 helped as bandwidths as low as 0.37Hz were possible.

When fitter I want to try infra-red LEDs instead.

See https://sites.google.com/site/g3xbmqrp3/optical/481thz-nlos.

Sunspots and 10m propagation - Monday May 25th 2015

Sunspot count is 74 today (K=1) but 10m propagation is again expected to be "poor".

UPDATE 1253z:   So far today, apart from a couple of locals on 10m, only CT1JTQ (1843km) by Es. No DX seen, well not yet, on 10m WSPR.

UPDATE 1834z:  A little Es and single hop F2 spots from EA8BVP (2986km) but no "real" DX on 10m so far today.

Flotta Island IOTA

Southgate Amateur Radio Club News reports that the Orkney Amateur Radio Club is activating Flotta Island in the Orkneys mid July. I am not a great DX chaser, but I can understand the motivation behind IOTA. Of all the DXing activities, this is the one I could imagine doing.

See http://eu009.webplus.net/ .

Grandchildren this week

Over the next week, we have both sets of grandchildren staying with us. For the first half of the week, my shack houses a travel cot so I have far less access to the amateur radio gear and PC.  I hope to remain on 10m around the clock ( PC only needed to sync the clock) but my access to 6m will be much more restricted. Although tiring, the grandchildren take priority.

UPDATE 1945z:   Es (and EA8BVP via F2) on 10m WSPR during the day, but no Es evidence here on 6m WSPR where only G stations have been spotted and spotting me.

UPDATE 2052z:   EA8BVP (2986km) spotted my 500mW 10m WSPR beacon 21 times today, so far.  I presume these were all single-hop F2.

6m WSPR this morning

So far today, only G stations spotting me and being spotted on 6m WSPR.  No Es seen yet on the band. G3ZJO (79km), G0LRD (25km), G8EPQ (77km), G0OQK (98km) and G4APB (88km) so far in the 6m WSPR logs.

W5OLF WSPR beacon

W5OLF - WSPR-AXE-CW beacon

There are other solutions around for WSPR (like the Ultimate 3 kit from Hans Summers - excellent I am told) but I have had Wolf's 10m 500mW,  fully stand-alone, WSPR beacon (WSPR-AXE-CW) running more or less continuously for 6 months now. This fits in a small Altoids sized box and needs no PC at all. The frequency is randomised but always on TX. My antenna is a 3 band low wire and certainly not the best for 10m. Despite this, it has been copied in the USA most days for months and has been spotted in every continent on the planet including Antarctica and Australia. If I am around, the 10m WSPR beacon is usually on. If you are after a fully stand-alone WSPR beacon for 30m, 20m or 10m these beacons are on a single PCB and work well. As the photo shows, the board is simple and the kit comes with a pre-programmed chip with your callsign, locator and power ready for use.

See https://sites.google.com/site/g3xbmqrp3/hf/w5olf .

Sunspots and 10m - Sunday May 24th 2015

Sunspot number today is 69 (K=2) and 10m propagation expected to be "poor".

UPDATE 0905z:   EA8BVP (2986km) was again spotting me very early on 10m WSPR. I presume this is F2. Otherwise just local G4IKZ (18km) spotting me. No real DX spotting me, well as yet!  Always hopeful, even though the 10m forecast is "poor" today again.

UPDATE 1038z:  CT1JTQ (1843km) spotted me a couple of times recently by Es, which appeared about 20 minutes ago here on 10m WSPR.

Overnight surprise on 10m

At 0132z I was spotted by CT1JTQ (1843km) on 10m WSPR. I assume this was an isolated Es opening, but was surprised by the time, which was the middle of the night. The beauty of WSPR! Leaving WSPR running whilst getting on with other things is certainly a good idea. How else would such a fleeting 10m opening,  in the middle of the night, be noticed? 

This is especially true on 6m where WSPR should allow short openings, often at odd times, to be noticed and recorded. Often short openings can be missed.

How simple?

Some years ago I attempted to see how few components were needed to communicate on 10m. The Lesser Chirpy was the best I could manage. This was a derivative of The Chirpy, which worked, but had far too much chirp!

Looking at the circuit I see I could save 1 component by replacing C1 and C2 by preset C's and shorting out C3. This would allow the TX-RX offset to be set. If one was made a variable rather than a preset the RX-TX offset could be adjustable.

Since being ill I have not tried the rig. A limitation was the limited RX sensitivity, meaning only stronger stations would be workable.  However, the rig does work and is very simple. Another possibility is to switch to an external RX but allow the internal RX to be used when signals are strong enough. The TX power is certainly enough to span the Atlantic and work all over Europe.

The secret to low chirp on 10m is the use of FSK rather than CW. Essentially the TX changes frequency rather than go from RX to TX every time. This means full break-in is not possible in such a simple circuit. Can you do better? If so, I'd love to see the schematic please. I make no great claims for my circuit, which is an amalgam of ideas. Pure fun!

See https://sites.google.com/site/g3xbmqrp3/hf/chirpy .

6m Es

EA1KV (1304km) has spotted me twice, so far, on 6m by Es.  I am sure there many be other Es stations this lunchtime and teatime on 6m WSPR.   Apart from this Es opening, all spots (given and received) have been G stations - G3ZJO (79km), G8EPQ (77km) and G6IMT (65km).

UPDATE 1600z:  Teatime and the Es is back again on 6m.  EA1KV (1304km) is again spotting my 1W ERP on 6m WSPR.

UPDATE 2002z:   No further 6m Es WSPR spots seen here this evening.

Sunspots and 10m - Sat May 23rd 2015

Sunspot number has risen to 81 today (K=1) but forecasts for 10m remain "poor".  It is too early really to judge here but apart from EA8BVP (2986km - single hop F2) there is no evidence yet here at 0920z of any long distance spots of my 500mW 10m WSPR beacon. Others running more power may get spots from further afield?

UPDATE 0947z:   CT1JTQ (1843km) now spotting me several times, I assume by Es.

UPDATE 2200z:  EA8BVP (2986km) was spotting me as late as 2120z this evening, but no USA spots again.

EA8BVP (2986km) - early 10m WSPR spots today

EA8BVP (2986km) was spotting me by F2 as early as 0724z this morning on 10m WSPR.  No other spots apart from G4IKZ (18km) and G4KPX who I think is reporting the wrong QTH locator unless he is on holiday somewhere.

Pixie kit prices - truly incredible prices

Since my post earlier on this blog about low cost 40m Pixie kits from the Far East, I have been told that Bangood was selling these kits today for a staggeringly low price! This information is thanks to Spence M0STO. Earlier they were for sale at an incredible £2.67. 

At this price you might just buy the crystal here in the UK!  The kit comes with ALL parts (apart from battery, key and headphones) and a very nice silk-screened PCB. Don't forget this is with FREE shipping.  Unbelievable.

My kit from them worked first time. It was the first time I'd built anything in a LONG time because of my stroke. At this price it is an offer too good to turn down. AM breakthrough was perfectly usable (i.e. low) and RX sensitivity fine. I got over 400mW out too. Don't forget, this is a complete 40m CW transceiver.

Sorry for the double post but the kits are here and the Customer Service is second to none. Beware the prices change daily inline with currency. http://www.banggood.com/DIY-Radio-40M-CW-Shortwave-Transmitter-Kit-Receiver-7_023-7_026MHz-p-973111.html

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.

UK Earthquakes - NOT amateur radio

Earthquakes are far less common in the UK than in some other countries, but they do occur.  Last night one occurred in Kent shaking homes and waking people in the middle of the night. This one was 4.2 on the Richter scale. This one was felt by my son near Canterbury and they think some tiles came off their cottage roof.  They live in Sturry, which is just a few miles east of Canterbury.

Some UK earthquakes have caused real disruption and damage. This one must have been quite a shock to those that were aware of it. Being in the middle of the night, many may have been totally unaware that it happened at all.   Even though this one lasted several seconds it was nowhere near the force of the recent ones in Nepal which were many orders of magnitude stronger.

The strongest earthquake in the UK in recent times was in Colchester in 1884. It measured 4.6 on the Richter scale. Some reports claim up to 5 people died.

FT817 replacement at last?

It may be on its way, late, but on its way at last:

K3NG reported on www.amateurradio.com on his visit to Dayton:

"Yaesu did not announce an FT-817 replacement, which salespeople in the booth sheepishly acknowledged."

I wonder if they plan to launch this by Christmas? I expect it will push C4FM. As Yaesu has missed the last solar peak, I wonder if this one will include 1296MHz and omit the lower HF bands? One covering all bands from 12m-23cms with auto-ATU on HF would be good. I have already said the features I'd expect in earlier blog posts.

Sunspots and 10m - May 22nd 2015

Sunspot number has dropped to 36 (K=1) and 10m propagation is expected to be "poor". I am not expecting great things on 10m today.

UPDATE 1757z:  Same old culprits on 10m WSPR today!  CT1JTQ (1843km) via Es,  EA8BVP (2986km)  via F2 and G4IKZ (18km) local.  No real DX seen, well not so far. I shall be on the band probably all night, so should catch any late opening to the USA although I am not expecting the band to open, but I am often wrong!

UPDATE 2017z:  Still no stateside DX on 10m this evening.

10m - disappointing today

With the best of the day now gone, it was a disappointing day on 10m WSPR.  In all, just 4 stations spotted my 500mW WSPR beacon. EA8BVP was again the best DX spot at 2986km. He has spotted me most days now for months by single-hop F2. Other Europeans were probably Es.

I am still on the lookout for a really big Es opening to places outside Europe, maybe South America or Japan.

Unique station spots on 10m WSPR today.

DST 100 receiver

My very first communications receiver weighed a ton (it took 2 people to move it!) and was a DST100. I believe it was made by Murphy during WW2. This receiver, I have since learnt, was designed for intercept listening. It was built like a tank with a huge rotary turret tuning unit. The radio cost £7 from a local garage and it was overhauled (new valves?) by (the now late) G3CHN. It covered from around 50kHz to over 30MHz and heard some impressive DX. I was always puzzled why signals were so broad on the lowest range, not realising at the time that it covered 50 to about 150 kilohertz!  This was in 1962.

At that time there was little amateur band gear available (none from Japan) and lots of us used WW2 surplus gear which was available at low cost from many suppliers. Popular receivers were the AR88 and CR100. Transmitter-receivers included the WS19, WS38 and 52 sets.

Amateur radio in the 1950s and 1960s was quite different with lots of HF AM still and most people building their own transmitters. SSB was in its infancy. In many ways it was the high point of the hobby, although today we are blessed with low cost gear, free software,  more modes and more bands. The hobby means different things to different people. Long may it continue.

See https://sites.google.com/site/g3xbmqrp3/hf/dst100 .

6m WSPR update

So far on 6m, just the usual spots exchange with G8EPQ (77km). No Es seen here on 6m today yet. I shall stay on the band all day to check though.

UPDATE 1818z:  G4AYT (114km) has been spotting me this teatime on 6m WSPR. Very low Doppler, so I am wondering if this is pure tropo?

Sunspots and 10m - May 21st 2015

Sunspot number has fallen to 61 today, but the K index is down to 1 indicating more stable conditions. 10m propagation is expected to be "poor" again today, although Es may well help liven up the band. I have already had lots of 10m spots by EA8BVP (2986km) by F2 and CT1JTQ (1843km) by Es. Just hoping for further afield, but this is probably less than likely. We'll have to wait and see.

160m indoor loft antenna

Some years ago G6ALB and I wanted a simple talkback link that we could use when co-operating on experiments. We were 3km apart with Andrew being in the next village. We immediately thought about simple AM rigs for topband (160m).

As I had no 160m antenna, I built the design linked here. This antenna works well with best WSPR spots being over 1000km.

We decided that topband was too noisy for our simple AM rigs for our intended purpose. The noise floor at both our locations is very high on 160m.  I have since moved QTH but we are still thinking about this link. We are now 3.3km apart. Probably 6m would be a better choice as less noisy and we both have vertical antennas.

See https://sites.google.com/site/g3xbmqrp3/antennas/160m_loft_ant .

10m WSPR - early spots by EA8BVP

EA8BVP (2986km) was spotting me early today, I presume this is F2 propagation. This is promising for the rest of the day, even though the 10m forecast is "poor". Otherwise just local G4IKZ (18km). No Es or GDX by tropo or aircraft seen yet, but it is very early.

UPDATE 1020z:   Apart from EA8BVP and G4IKZ, 10m WSPR is very quiet so far this morning.

UPDATE 1735z:  CT1JTQ (1843km) has been spotting me a lot of the afternoon. I think this was Es.

UPDATE  1940z:  F and OE spotting me on 10m WSPR. More Es.

6m WSPR this morning

I have been spotted by G8EPQ (77km) and have spotted G8EPQ as well and spotted G0OQK (98km) this morning on 6m WSPR.  As yet, no Es seen here but it is still very early. Both G8EPQ and G0OQK may have been aircraft reflection assisted I think.

UPDATE 1732z:   2E0BMG (62km) was spotted at 1600z.

UPDATE 2034z:  M0YOU (116km) was spotted at 2010z. The Doppler suggests aircraft involvement.

472kHz (630m) WSPR overnight

Late yesterday evening I changed from my "strapped feeders and loading coil" 630m antenna to the earth-electrode antenna that I'd been using all winter on MF. Spots on 472kHz (630m) WSPR  by G7NKS (46km) immediately jumped upwards by 6dB. This may be directionality, but results were definitely better.  I know my RX is deaf on 472kHz.  It tells me the "strapped feeder" antenna is not that brilliant!

Overnight the best DX was reception of DK7FC (669km) who is always a good signal and a spot by PE1RKT (285km). When I went back to the earth-electrode on 472kHz I resumed 10m WSPR beaconing but I was only copied by G4IKZ (18km) during the overnight period.

Now I am back on 6m (rather than 630m (472kHz)) and 10m WSPR.

Sunspots and 10m - May 20th 2015

Sunspot number is virtually unchanged at 84 (K=3) and 10m propagation is expected to be "poor". So far just local spots on 10m.

630m this evening?

In view of the dire conditions today on 6m and 10m, I am slightly tempted to try my QRP ERP on 472kHz WSPR (630m) this evening and overnight. Noise levels will be higher but it would be interesting to see if anyone copies me or if I copy anyone. I'll decide after tea.

At some point I want to try 136kHz again. I can run my QRP QRSS3 beacon into my earth-electrodes and go looking locally with my mag-mounted E-field probe. At the moment I don't feel fit enough though. From the old QTH I managed 250km on 137.5kHz WSPR. I need to make a better antenna for LF/MF at this QTH. I have space for a long wire with some vertical loading. Maybe in the autumn?

UPDATE 1852z:    Just returned to 472kHz (630m) WSPR using the strapped feeder of my Par 10/20/40m wire antenna tuned against ground with a loading coil. As yet, no reports given or received. Will stay on 630m late tonight and possibly overnight. QRT on 10m and 6m as I need the antenna (for 10m) and the PC and FT817.

UPDATE 1940z:  Still no spots given or received on 472kHz.  Since the winter there are fewer active stations it would appear.

UPDATE 1942z:  With only 10 active 472kHzWSPR stations shown as active in the entire world, I think I shall be pleased to get any spots in the log today.

UPDATE 2015z:  4 spots received from G7NKS (46km) are the only spots so far on 472kHz. Reports are within 1dB, so very consistent, if weak.

472kHz band WSPR spots by G7NKS this evening

Amateur VLF DXing

Operating an amateur station at VLF is a very specialised area of experimentation. There are basically 2 different threads (1) earth-mode or utilities assisted earth-mode with propagation mainly along or close to roads and (2) radiated DXing in which a VLF signal is actually radiated and propagated to great distances. With (1) I have managed 6km with QRSS3 with 5W from a TDA2003 audio IC at 8.97kHz. Earth-mode gear can be low powered and simple to build.

VLF amateur signals

With (2) the Atlantic Ocean has now been crossed, i.e. quite remarkable distances with amateur powers and antennas. Usually very large loading coils are needed and making these can be "challenging". As high voltages are likely, great care is needed. Of course, most DXing is done with very long stable transmissions in very narrow bandwidths. Most amateur VLF gear is home made with free PC software to allow signals to be seen. Casual listening is not effective.  Most operation is now around 8.300kHz as this is unallocated in many countries.

News of VLF activity may be found at https://sites.google.com/site/sub9khz/ .