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.

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

Hello,

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!

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.

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.

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.

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).

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.

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. 

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.

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.

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.

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

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.

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).

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.

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?

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.

Good 500kHz DX overnight with 1mW ERP

For the first time in more than a week I ran the WSPR beacon through the night. Best DX reports were from GM4SLV, GM0UDL and Lubos OK2BVG at 1232kms. Lubos sent me this picture of his fine shack. Notice the lovely LF/MF loading coil on the left hand side and the LF receiving loop in the corner. Lubos has a very nice collection of equipment. He has now managed to receive me on several different occasions on 500kHz.

More new ones on 500kHz

A new station has reported my 500kHz WSPR signal this evening: ON4BB in JO21 at 294kms. Later, GM0UDL spotted me from up in IO77 square at 659kms, bringing the total unique WSPR reports up to 76.

AA1TJ's success with the XBM80-2

Mike Rainey AA1TJ has built his version of the XBM80-2, but LESS the audio stage, using instead his 600 ohm magnetic headphones via a transformer, and has managed some QSOs well over 100 miles. He changed the emitter resistor to 15k to reduce the signal radiated on key-up (backwave) as well as made a link coupled bandpass filter output/input circuit. This would reduce the amount of AM breakthrough usefully.

76th unique signal report on 500kHz with 1mW (or less) QRP

This evening, I was WSPR decoded by a new station in the Netherlands PI4Z in JO11wm at 260kms. This brings the total number of stations who have sent me reports on the band to 76 now (72 via the WSPR database, 2 emailed WSPR reports and 2 CW stations) in a total of 10 countries. Best DX report still 1232kms.

CQ-PA article on 500kHz

The Dutch magazine CQ-PA has quite a large article on 500kHz operation this month. I was very pleased to see my little IRF510 based transverter circuit and my small vertical antenna were shown. Amateurs in the Netherlands have recently been granted access to this band.

Nuclear Fusion breakthrough?

Some recent research may have helped the dream of unlimited and pollution-free energy from nuclear fusion become a big step closer. Scientists in the USA have demonstrated that containment of atoms for fusion using laser beams is far less problematic than first thought. Unlike current nuclear fission, nuclear fusion reactions create no radioactive waste materials. Potentially nuclear fusion reactors, if created on a commercial scale, could dramatically help supply clean energy the world so badly needs. See http://news.bbc.co.uk/1/hi/sci/tech/8485669.stm

Super-efficient VHF antenna?

See http://www.nist.gov/public_affairs/techbeat/tb2010_0126.htm#antenna

"The National Institute of Standards and Technology (NIST) and partners from industry and academia have designed and tested experimental antennas that are highly efficient and yet a fraction of the size of standard antenna systems with comparable properties. .....NIST engineers are working with scientists from the University of Arizona (Tucson) and Boeing Research & Technology (Seattle, Wash.) to design antennas incorporating metamaterials—materials engineered with novel, often microscopic, structures to produce unusual properties. The new antennas radiate as much as 95 percent of an input radio signal and yet defy normal design parameters."

Mosquito single IRF510 transceiver

EA3GHS and EA3FXF have produced a single IRF510 FET based version of his Mosquito transceiver using a PC as the back end of a software defined radio (SDR). In essence, the FET is used as a regenerative or direct conversion receiver - I think the two are indestinguishable in a single stage RX - with audio coupled to the sound card via a mains transformer which steps up the impedance. The IRF510 is capable of up to about 7W in this application. Coupled with an SDR back-end and this is SOME simple transceiver, especially if the crystal is VXOed.

Web based HF receivers (SDRs)

Web software defined receivers (SDRs) are becoming quite common now. They allow you to eavesdrop on a number of different HF bands and tune around for stations as if you're located at the distant location. The best place to find a list of these receivers is at http://www.websdr.org/ . I have used the one in Twente, Holland to see if my QRP 80m signal got to The Netherlands (it did) and to check activity on bands like 500kHz. Sometimes these SDRs are located in places where the background noise levels are very low too.

Apple iPad tablet launched

Apple has finally revealed its new killer product - the iPad. My son has an iPhone and is very pleased with it. I doubt I will be persuaded to buy either. I have been tempted with the Apple iPod Touch which is a very desirable product.

500kHz again tonight

After a break of a couple of days, I'm back on 500kHz WSPR again this evening with my 1mW ERP. The reports are still coming in from far and wide (G, GM, PA and LA so far), although no super-DX from central Europe yet this evening.

Walford Kits "Fivehead" SSB transceiver

A friend of mine is building a Walford Kit "Fivehead" SSB transceiver. He has got the kit, but was surprised to find the parts placement was not silk screened on the PCB; I guess this is a cost saving measure.

Although there is a not-to-scale layout, a clear colour photo from above of the assembled board from the component side would help him a lot. He's asking Tim if he has one he could email, but does anyone already have one they could email me please?

XBM80-2: a 2-way QSO and report

This morning I worked M0DRK using my tiny 60mW XBM80-2 transceiver I designed last week. It uses just 13 parts plus the crystal, earpiece and optional frequency offset switch. My report for Derek was 599 and he gave me 599+40dB. Derek is in the same village. Also monitoring was G4LHI in Huntingdon 32kms away and he reported my signal was as strong as Derek who was running 5W.  In fact 60mW is only going to be about 3 S points down on 5W. I also heard GM3JUD when listening on the XBM80-2 on 3.560, but was unable to raise him.

Shortwave in the 1960s - interval signals montage

Yesterday I found this wonderful link which is a montage of 40 different old shortwave interval signals from almost 50 years ago. Get a coffee, sit back and listen.  Imagine you are listening on your one valve radio in your bedroom in 1964.  It brings back such happy memories that I am almost tearful with nostalgia.

http://garlinger.com/QSL/montage.mp3

G3ZJO in QRSS3 on 500kHz

G3ZJO has a QRSS3 beacon sending in FSK built in Altoids tins and running QRPp power. This is is a screenshot (from Spectran) of his signal this afternoon. I have superimposed his callsign, which is clearly visible on the upper line. The first dash of the G in his call is missing in my capture.

Simple 80m CW transceiver

Want to try something really simple?  I am now waiting to have a QSO on 80m CW using my XBM80-2 transceiver that I put together in the week. Pout is 60mW. The only switching between TX and RX is by the morse key. Additional offset can be had with the switch in series with the crystal. Skeds with local stations are being arranged.

ERP on 500kHz (part 2)

Yesterday I did a recalculation of the G3XBM ERP based on the classic formula and re-measurements of my antenna current. My antenna is a 5m long vertical with a spiral top hat of about 7 turns about 1.5m x 1.5m. Not being clear how to model the top hat I assumed effective heights of 5, 4 or 3m. The measured antenna current is 0.12A. My results are as follows:

Assumed effective height 5m     ERP = 1.53mW
Assumed effective height 4m     ERP = 0.98mW
Assumed effective height 3m     ERP = 0.55mW

So, I believe my 1mW ERP previously calculated is not a bad estimate, and it may indeed be lower than this figure.

Rik ON7YD (OR7T) has just sent me this email:

"I simulated the antenna based on your description (with MMANA) and the current through the vertical wire seems to be quite constant. So the tophat works well and the effective height will be more or less the physical height. The simulation gives a radiation resistance of 0.074 Ohm, so with 0.12 A a radiated power just over 1mW EMRP (1.75mW ERP). In the real world it will be some dB's less (as Jim stated recently), probably something like 0,5 to 1mW ERP.  Very impressive that it covers over 1200km."

JT4A mode on 500kHz

The next (operational) project is emerging from the mists..... Several people have started to experiment with JT4A WSJT mode on 500kHz. This allows basic EME/MS style QSO exchanges so should allow me some 2-way contacts on the band with my low ERP. Still to work out how to run the software though: when I tried the other night I could see strong traces but no decodes. Getting this sorted will be half the fun. Then I might try to mode on VHF too. JT4A uses a bandwidth of 17.5Hz with tone spacings of 4.375Hz and can decode down to -23dB S/N. This is somewhat less sensitive than WSPR but would still allow QSOs with quite a large number of the stations who've heard me on WSPR.

QRP Books

International QRP Collection is a new book bringing together articles from magazines around the world on QRP (low power) radio. There are articles on commercial equipment, homebrew ideas, test equipment and operating on bands from 160m to microwaves plus much more. A friend who is not too familiar with QRP thinks it is a good introduction, but I must admit I was disappointed: the collection seems disjointed and, in my view, a better set of articles could have been put together. As an example, the intriguing transceiver on the cover does not appear in the articles inside! Overall, I'd give this one 6 out of 10. The book is available from the RSGB. 

QRP Basics by G.Dobbs G3RJV is a much better book and worth buying.

The Pixie Files

The Pixie and Micro80 are  well known simple transceivers for any HF bands. I've built both in the past and they do work well considering their lack of complexity. The main limitation is the receiver which uses the TX PA as a simple mixer. For those wanting more information on the Pixie and its derivatives check out The Pixie Files which is a collection of articles from SPRAT.

ERP calculation on 500kHz

I've recalculated my ERP based on a better measurement of antenna current. I was using a dust iron core for my current transformer, so swapped this for an FT37 ferrite toroid today and got a lot more current measured now. My antenna current is actually around 0.12A. My antenna is 5m long with a small spiral top so the effective height must be <5m. Even putting in 5m into the classic formula I cannot make my ERP exceed 1mW. I make it more like 600uW. Interestingly this is 20dB more than the original estimate from M0BMU and since then I'd increased the ERP, I believe, by around 20dB which would also make it 600uW. Of course the margins of error must be large.