28 Feb 2010

11th country on 500kHz

Just had a 500kHz WSPR report from MW0CVT 250kms to the west of me. This is now my 11th country from which I've had reports on the band. This is also my 83rd unique report on the band.

Amateur DXing below 9kHz (VLF)

Some recent discussion on the LF Reflector is suggesting that distances of >100kms should be workable with amateur stations below 9kHz, albeit running QRO exciters. This would be possible with optimised stations and antennas and very slow QRSS modes. As an example, see the email posted this evening by RA9MB:
I was wonder if it is posible to use a loop on 9 kHz. Serious problem to radiate 9 kHz is high voltage we saw. Loop has that advantage that voltage is not too high. Then i do some estimations. Let's assume vertical loop 15m x 50 m with 20 mm diameter coper tube as a wire. Then effectivity of such a loop on 9 kHz is about -65 dB. It is adequate to radiate 1 mW
on 9kHz (I=250A, TX power about 4 kW). We saw such a radiation should give abt 100 km  distance in QRSS. Besides such a loop is well suited for 136 kHz. On 136 kHz it effectivity should be about -25 dB. Not too bad: 1 W radiation with 400 W TX :-)

26 Feb 2010

QRP transatlantic on 80m

Just got a report from W1XP on 80m WSPR when running just 1W into the 5m long vertical. DX is 5280kms. Report suggests that 500mW would also have crossed the pond.

New Zealand gets 500kHz (for now)

From March, New Zealand amateurs will be allowed to use 505-515kHz. The number of administrations making temporary allocations is increasing all the time now. Expect some ZL-USA (and maybe Europe?)  tests before long on the band. I wonder who will be the first to receive some 500kHz WSPR beacons from the Antipodes?

Australia on 40m QRP tonight

It really is too easy with WSPR on HF.  Last night some reports from Antarctica and tonight a brief 5W transmission on 40m got me another report from VK6POP in Australia. One of my projects is a micropower WSPR beacon for 10m, but it will have to be something like 10mW to be anything like a challenge :-)

First sub-9kHz NoV application with OFCOM

G7NKS has already submitted his application for an NoV to operate below 9kHz. Mine will be prepared in the next few days. Approval (or rejection) may take some time as OFCOM has to consult with the Met Office first. The Met Office monitors <9kHz for sferic activity to track storms and lightning.

25 Feb 2010

WSPRing to Antarctica on 30m

This evening my 30m WSPR signals got to Antarctica with several reports from the German Research Station DP1POL in IB59 some 13690kms to the south of me. Best report was -18dB S/N suggesting that I would have been copied running just 500mW.

NoV permits for operation below 9kHz

OFCOM has informed me today that, subject to acceptable outcomes of consultation with other sub-9kHz spectrum users such as the Met Office, they will consider issuing NoVs (similar to those issued for 501-504kHz) to existing UK radio amateurs to permit operation at frequencies below 9kHz. Any such operation would be on a non-interference basis.  Application forms should be submitted to Rod Wilkinson at OFCOM (with as much detail as possible) using the NoV form available at http://www.ofcom.org.uk/radiocomms/ifi/licensing/classes/amateur/applications/ofw306.pdf

Lowest frequency commercial/military VLF transmissions?

The two lowest VLF frequencies in use are apparently:
  • 11.904 kHz  RSDN-20 network, a Russian navigation VLF system with transmitters located in Novosibirsk, Krasnodar, etc
  • 82 Hz  ZEVS system, an ELF transmitter located on the Kola peninsula and dedicated to strategic transmissions to Russian nuclear submarines.
Jean-Louis F6AGR receives both stations near Paris with an E-field receiver consisting of a home-brew receiver fitted with a FET/BJT front end and a 1m long cylinder vertical antenna.

Improved VLF converter

Chris HB9DAO has sent me a copy of his modifications to my SAQ VLF converter that was published a few years ago in SPRAT. His changes make the converter a bit more "bullet proof" in the European environment where there are lots of very strong signals in the VLF-MF frequency range. The schematic is attached.

TW Communicator Restored

I've just had an email from Tom Withers G3HGE who designed the wonderful range of TW Communicator transceivers for 160, 4 and 2m back in the 1960s. These UK products were ahead of their time being single unit transceivers for popular (single) bands. Tom has been restoring a 2m version and he sent me a photo of this (see left). It looks a real beauty. The TW brand is coming back, not with transceivers sadly, but with at least one new interesting product.

10m WSPR

Back on 10m WSPR again today. So far just the usual reports from G4IKZ although there is DX from Reunion Island coming through already. I've not been at all well lately so this has prevented me re-erecting my proper 10m halo well up on the mast. When back up, this should increase the ERP by several dB.

23 Feb 2010

Back on 500kHz: 80th unique WSPR report received

This afternoon and this evening I'm beaconing (and listening) on 500kHz WSPR with the 1mW ERP. Just received my 80th unique WSPR report on the band, this time from G0NNF. Lots of Dutch stations are on 500kHz recently.

Namibia on 10m WSPR

Just spotted a new one on 10m WSPR today: V53ARC running just 1W from 8473kms away in Namibia was received at -23dB S/N. Also copied G3JKV some 123kms away, presumably by ground wave or tropo.

22 Feb 2010

UK permits for transmissions below 9kHz?

There has been some debate today on the RSGB's LF Reflector about how legal amateur transmissions in the UK would be at frequencies below 9kHz. Apparently the old Radio Communication Agency failed to come back with an answer to a request around 2000-2001. We're wondering what OFCOM would say today, so I've emailed them to ask. They have already replied and told me the query is being forwarded to their Spectrum Management Team and they are considering their answer over the next few weeks.

Communication over any distance at frequencies below 9kHz is a real challenge and the modes used are usually conduction through the earth or sea (so called "earth mode") or by induction. Very little power is radiated unless enormous powers are used e.g. in the USA's Project Sanguine when megawatts were used at 76Hz to communicate worldwide with submerged submarines. Distances much beyond 10kms are highly unlikely with amateur powers and systems.

Reunion Island copied again on 10m WSPR

FR1GZ has been copied very well here again this afternoon on 10m, some 15dB above the typical threshold for WSPR signals. He is running 10W, so there is a good chance he will copy my 5W from the FT817.

21 Feb 2010

Reunion Is on 10m WSPR

This morning I was decoding the 10W WSPR signals of FR1GZ in Reunion Island at 9724kms. I was hoping 10m would open to the USA this afternoon and I'd hear some W and VE stations coming through in the ARRL CW DX contest, but nothing heard so far. 15m is full of USA CW stations though.

RF Cafe

This looks to be a very useful resource for both professional and amateur RF designers with lots of useful links, software and calculators available. See http://www.rfcafe.com/

Iceland to get 500kHz band for 1 year

Hams in Iceland have been given access, by special permits, to the 493-510kHz band until the end of the year with a power limit if 100W.

20 Feb 2010

2010 ARRL International DX Contest

Conditions on 15m were good enough for some solid CW QSOs across the pond this afternoon. Worked stations in New Hampshire, Connecticut and Virginia when running 5W QRP. I did also check up on 10m but didn't hear any stations when I listened between 1600-1720z.

Communications below 9kHz

This has just been posted on the LF reflector by DO1KHS. I wonder how many other people have experimented with communications at radio frequencies below 10kHz? If so, do share your experiences here. See also my website on the subject at http://sites.google.com/site/g3xbmqrp/Home/10khz

Some years before, some experimental licences for ham radio below 9 kHz were issued in germany. Meanwhile this frequency range is free as the Bundesnetzagentur has confirmed last year.

Transmitter is an Präcitronic GF62 Level Generator actually at 8,79 kHz. PA is an old homebrew NF-Amplifier with 2x 2N3055 and about 40 Watt at 4 Ohm into a 100V ELA transformer. Antenna is a T-Antenne of 10m with 20m top capacity and poor ground.

Receiver is a portable sferics RX that I built some years before (AATIS). Unfortunately its whip antenne is highly influenced by trees and houses.

The fact that I can hear (!) my beacon in normal CW up to 100m in an city environment with a highly unmatched antenna makes me believe, that in a better environment and with a matched antenne and with help of ARGO one can make tests over longer distances. But even from my QTH in the city the ODX ;-)) surely can be improved.

The mean problem now ist how to match the antenna . . . - or using ground antennas vor TX, RX or both.

vy73 Horst

10m - signs of life

OD5NH has been a decent signal on 10m SSB this morning. Have not managed to work him (yet) but did get a "QRZ the x-ray?" with 5W SSB to the 500kHz vertical. 12m is also open with EA8CQW on CW. You really do sense that the higher HF bands are coming back to life again after a long period of hibernation - great!

19 Feb 2010

Lightbeam communications

Before I became a radio ham, a friend and I had our first phone wireless QSO using a small torch bulb modulated with a couple of germanium transistors. The DX was across the road, about 20m at most. At the far end the receiver was based on an OC71 with its black coating scraped off, which made quite an effective photo transistor. These days there are much better ways. For some examples, see some of the fascinating links at  http://www.carolinaflashers.org/ . One of these days I must revisit optical communications. The picture on the right is from http://www.laud.no/ww2/lispr/index.htm and shows a WW2 lightbeam communications device used by the German Army.

More 500kHz reports

This evening, 2 new stations reported my 1mW ERP 500kHz WSPR signal: PA1GSJ at 274kms and G0API at 232kms. A few days ago I was copied by G1IRG at 74kms. This brings the total number of unique WSPR reports to 79 and 81 total unique reports including CW contacts.

Dell Heaven!

Well, I have to say I was impressed with Dell today. Having suffered a series of blue screen disasters in the last month or so and having tried various things to fix it (roll backs, defrags, de-installs of software, etc) without success, it was time to contact the technical support help desk. The last I did this some years ago it took me several days to get through. Today I was connected to the Indian help-desk in 5 minutes or so and over the phone they checked the HW was OK. The software guy came on line next to instruct me how to load a clean Windows 7 installation. BTW, they rang me back, so Dell paid for the call after the first 30 minutes. An hour later and I have what seems like a brand new, stable Windows 7 installation. They charge for software support (NOT covered by the 4yr at-home warranty) but I was glad to get my wife's machine working again so quickly.  It is nice to be able to say something very good about Dell and the service from their lads in Bangalore.

18 Feb 2010

Dell Hell

I have just wasted a day of my life ....

My wife's 8 month old Dell Inspiron laptop running Win7 keeps coming up with the blue screen of death (again) and no matter what I try (system restores to various dates) nothing fixes it. I have a 4 year HW warranty  but this does not cover software issues and I suspect this is software. I'm unable to do a full restore to the factory image as no backup is included on the hard drive.  I'm no PC expert and get totally frustrated by this sort of issue and the fact that Dell help is so poor: you just go around in circles.

My little Asus EEE, that I am using now to type this, has NEVER failed, ever.

Fivehead 20m QRP SSB transceiver kit

A friend of mine, Ted G4NUA, is busy building one of the Walford kits called the Fivehead. He is doing the 20m SSB version which puts out around 1.5W pep when completed. So far he has got the RX part working (see picture of the build so far), which shares a lot of the IF with the TX part. The PCB is not silk screened making construction a bit more tricky than for an Elecraft kit. This is presumably to reduce the kit cost. When finished it should make a credible QRP rig for 20m, although 1.5W on SSB is a bit lower than I'd like. There is an option for a 10W PA add-on if Ted struggles to get contacts.

17 Feb 2010

SeeSaw - a new internet TV resource in the UK

Online TV service SeeSaw launched today, offering 3,000 hours of content from Channel 4, Five and older BBC programmes. This is an interesting development in Internet TV in the UK.  I don't watch that much TV myself, but my wife will love it.

16 Feb 2010

12m across the pond

Yesterday, Feb 15th, there was transatlantic DX to be heard on the 24MHz (12m) band. It was good to hear W stations again. It is only a matter of time now before the first decent F2 openings begin again on 10m. I have the feeling this will be in the next 4 weeks and we will not have to wait until the autumn. Occasionally there are E layer openings in the summer months but it is the REAL 10m and 6m F2 openings I'm looking forward to again: when 10m properly gets back into its stride there will be strong stations all the way from 28-29.7MHz and from most of the world at the right time of day. On favourable days in the autumn there will be openings to the USA and Canada from Europe on 6m too. Probably not this year, but there will be a good chance next (2011).

15 Feb 2010

10m WSPR

Whilst in the shack checking emails and my blog, I've been WSPRing on 10m. The only report so far is from G4IKZ not far from me. V53ARC is active on 10m and has been received in Europe today but I have yet to spot him.

13 Feb 2010

10m FM

This afternoon I called CQ on 29.6MHz FM but no-one came back to my call. Going back 20 years or so there was a lot of activity on 10m FM with many people in the UK using converted FM CB rigs. With 4W and a vertical half wave I could work out to about 30-40kms without problems. Sadly, activity is very low here now except when there is sporadic-E about. 10FM was a good way of checking DX as often quite distant repeaters would pop up out of the noise, especially ones on the east coast of the USA. 

12 Feb 2010

WSPR in QSO mode

Stations on 500kHz using WSPR in QSO mode are using the latest WSJT7 software used for modes like JT6m, JT65 and JT4. An option in the software allows the use of WSPR.  Stations are using frequencies outside of the WSPR beaconing sub-band of 503.8-504kHz. For the next few days my shack is being used as a bedroom for my little grandson, so it may be the middle of next week before I can try WSPR QSO mode.

11 Feb 2010

500kHz WSPR 2-way QSOs

This evening a few stations have been having 2-way QSOs using WSPR. I'm not exactly sure what the procedure is for this, but it is something I must try! This was a summary of the exchanges for a couple of QSOs:
213202  13   0 -0.5    -6  0  CQ G4WGT IO83
213602  10  -2 -0.3    -5  0  M0BMU S1
213602  16   4 -0.2     6  0  G7NKS IO92 20
214002  13   4 -0.3    -5  0  M0BMU S1
214402  16  -1 -0.5    -5  0  M0BMU R S6
214402  17   5 -0.5     6  0  G7NKS IO92 20
214802  13   0 -0.3    -5  0  73 DE G4WGT IO83

And Jim:
221002  10   4 -0.4    31  0  M0BMU S2
221402  10   4  0.0    31  0   G7NKS RRR
221802   9   5 -0.5    31  0  73 DE G7NKS IO92

Early 500kHz transatlantic reception tonight

WD2XSH/17 and WE2XGR/6 are being copied on WSPR by a few stations in the UK already this evening at 2230-2245. This is early, so it suggests conditions are good across the pond.

21MHz transatlantic - even at 1820z this evening

Conditions on 15m were good again today with the sunspot count still over 50 for the third straight day now. K1PU got me on my 5W CW just as the band was dying, but I missed my report in the QSB and lost him - 5 minutes earlier and it would have been a solid contact. Just noticed CX7CO (Uruguay) on 21.020 and coming up in strength.  At 1820 just worked WW2DX at 599 both ways when running 5W here. Definitely sounding like the good old days, although when the W stations start coming through regularly on 10m again we will know cycle 24 is truly in its stride.

A new station to appear on 500kHz - M1KTA

Dom M1KTA has just received his NoV for 500kHz and hopes to be active on CW (and WSPR I hope) very soon. Dom is not too far away from me (18kms), so a CW QSO should be a OK. It will be useful having another station quite close when experimenting.

10 Feb 2010

79th unique 500kHz report tonight

This evening, after a bit of fun on 21MHz CW earlier this afternoon, I returned to 500kHz WSPR whilst getting on with other things. Just received a report from G1IRG in IO92og and he is now my 77th unique WSPR report on the band and the 79th station to receive my 1mW ERP signal on the band.

QRP DXing on 15m CW

With the improved sunspot count yesterday and today 15m has opened up to the Caribbean and to the USA this afternoon. First QSO was 9Y4VU at 1400z then WX3B at 1450. Both were with 5W CW into my 500kHz vertical via the T1 auto-ATU.  I did take a quick look on 10m, but nothing heard hear. Later I took a go at PSK31 and worked RA3GI and US2IR on 15m with around 3W. It is so good to hear the higher HF bands coming back to life again: it has been a long time mostly quiet but the GOOD times are back.

8 Feb 2010

Sunspot count - 51

Just seen the sunspot number - 51. Things are looking up. If anything, I think that the rate of improvement in sunspot activity is slightly ahead of predictions. Maybe we'll have a bumper cycle 24 peak after all. Only time will tell.

Update: the count today is a staggering 71!!

VK2ZAY's version of the XBM80-2 transceiver

A few more people have been making the XBM80-2 transceiver. One is Alan Yates VK2ZAY who has made a de-luxe version with some refinements and additions. See it on his blog at http://www.vk2zay.net/article/238

6 Feb 2010

Problem with Sprint Layout 4 PCB package

Trying to do a small PCB for the XBM80-2 80m micro-transceiver using the Sprint Layout 4 PCB layout package I hit a problem: wanting to use a single sided PCB for low cost I did a groundplane fill. Then I wanted to connect certain pads to this. I cannot see how to do this! Several people have offered advice, but nothing seems to work: any attempt just results in a new clearance area being created. In the end I gave up and filled in the ground as another track and join it to the pads manually. The resultant draft PCB (1 inch square)  is shown here. I have not built it on a PCB yet, so this is only a suggestion. An SMT version could be half the size - i.e. VERY tiny indeed.

5 Feb 2010

XBM80-2 video and PCB (draft)

A short video about the XBM80-2 80m CW micro-transceiver. This is built "ugly style" on a piece of copper clad board. It will get put in a box soon! I've also been having a go at a PCB (just 1 inch square - 25mm x 25mm).

4 Feb 2010

Back on 500kHz tonight

Having been playing around with the XBM80-2 80m micro transceiver for a couple of days, I've not been on 500kHz for a bit. However, I am back again tonight with the 1mW ERP WSPR beacon. Reports from LA3EQ and GM4SLV amongst others received so far.

3 Feb 2010

Prosperity without Growth?

Prosperity without Growth? - The transition to a sustainable economy is a freely downloadable publication from the UK's Sustainable Development Commission. The report calls on world leaders to adopt a 12-step plan to make the transitionto a fair, sustainable, low-carbon economy.

Improvements to the XBM80-2 80m QRP transceiver

A few small value optimisations have improved the XBM80-2 transceiver. I've optimised the collector circuit values and this has resulted in 120mW output (was 60mW) from a 12V supply. The sensitivity is a little higher, the backwave level is lower, the amount of AM breakthrough from medium wave broadcasters is lower. At 4pm I was hearing DR2010O in the Ruhr area of Germany working all over Europe and could copy almost all the stations that he was working but I failed to break the pileup with 120mW. I'm beginning to think this little transceiver could be really useful. There is no reason why it should not work well on any band up to 28MHz (with less output) with a fundamental crystal. I'm wondering how it will perform on 50MHz with the collector tuned to x2 crystal?

1 Feb 2010

XBM80-2 heard at 430kms

This evening I tried listening for my 60mW CW signal from my XBM80-2 80m micro-transceiver on the on-line SDR at Twente in Holland. The signal was clearly audible at RST529 when I keyed the transmitter slowly! Distance is 430kms (267miles).

Another XBM80-2 QSO tonight

This evening I worked G6ALB 3kms away on the XBM80-2 60mW ultra-simple 80m transceiver getting a 599 report. Andrew was copied at 599 when he was using his 300mW TR6C4 simple valve transceiver which has a regen RX. Andrew also sent test transmissions using his signal generator and I was able to copy his signal when he was running 3mW output. So, the conclusion is, as AA1TJ has already proven, the design is quite a useful one and VERY simple.