Long-term Solar Outlook - downwards!

Chris N7ZWY has put an interesting graph on his website showing his predictions for the future solar cycle progression. His graph shows the solar cycle progressions since the 17th century and Chris's predictions for the future. No-one can be certain of the accuracy of predictions, but as time goes by we are gathering more detailed understanding. I have little doubt Chris is broadly right.

Chris says:

"The average sunspot count for October was 61.4, higher than last month and no indication of the final decline which should bottom out around 2017 or 2018, which will then be followed by two more similarly low sunspot cycles and then a third with almost no activity during a phase reversal."

See http://www.home.earthlink.net/~christrask/Solar%20Activity%201600-2100.pdf

Now, looking at the plot it is highly likely that the sunspot peaks for the next 40-50 years will be weak ones, or even non-existent. The next few years are likely to see the end of the good times on the higher HF bands. Those of us who were around in the 1950s and 1960s didn't know just how lucky we were. Many newcomers to the hobby at that time worked all over the world with 5-10W of CW and AM with S9 signals.

Flying Pig 40m 5W transceiver

Thanks to Dave in Jakarta (don't know your call Dave) I've been pointed towards the Flying Pig 5W CW transceiver for 40m from Kits and Parts.

The receiver uses a clever direct conversion design using an NE602 with some AGC applied to it. Like the RockMite, it uses some front end crystal filtering to help overcome dynamic range/overload  issues, but with the limitation this is a single frequency radio, for example parked on 7.030MHz, the QRP frequency. Still, a full 5W on the QRP frequency will permit plenty of QSOs.

This is the photo on the http://www.kitsandparts.com/ website

The best news is the price - $40 only, which is good value for a kit. Available from Dec 10th 2012 according to the website.

Drawing schematic diagrams

Several people have asked me what I use to produce schematic diagrams for circuits I put on my website and here on the blog. Well I use a package called sPlan which is available from http://www.abacom-online.de/uk/html/splan.html.  This is the package that many SPRAT authors use. Mine is an early version but the latest version is available for 39.9 euros.

Abacom has a range of useful resources such as front panel labeling software and some very simple PCB layout software.  sPlan is remarkably easy to use and a circuit like the Tenbox can be drawn up in about an hour, simpler circuits even less time.

The Abacom website gives details of distributors in many countries.

Wikipedia

en.wikipedia.org/

Don't know about you, but I refer to Wikipedia just about every single day. It isn't perfect, but it certainly is one of the most useful free resources on the Internet. The quality and quantity of data available there is nothing short of remarkable. I've added a few entries myself over the years too. As a thank you I made a small donation via Paypal and encourage you to do the same if you can spare a little.

As they say in their thank you email, the resource is used by people from all over the world including in schools in developing countries. By ensuring Wikipedia remains free and neutral we are helping to keep the Internet free for future generations.

Magnetic loop HF TX antennas

Although I have successfully used a large 80m sq vertical wire loop (made with 32 x 0.2mm PVC covered wire) on both 137 and 500kHz, I have never tried a hi-Q small loop on HF transmit. There is a very useful calculator available at http://www.66pacific.com/calculators/small_tx_loop_calc.aspx which suggests a 3m circumference loop using a 5mm diameter conductor - for example small bore copper pipe or a thick coax cable - would have a loss of only 0.9dBd and a bandwidth of 352kHz at 28MHz.  This would comfortably cover both 28MHz CW, data, WSPR and beacons without retuning.

An advantage of magnetic loop antennas is reduced detuning from nearby objects so this antenna, if mounted in the loft space, might make a neat and efficient stealth antenna for 10m. I guess one could even arrange to switch the tuning capacitor remotely so that several sub-bands could be covered. When using QRP power levels, as I do, the high voltages and currents that are encountered in small loops are less problematic. For example, choice of variable or fixed tuning capacitors is less onerous than if using 100W.

http://www.kr1st.com/magloop.htm

KR1ST has some nice information on magnetic loop antennas on his website.  I hope he doesn't mind me linking to the image of his magnetic loop on his site. There is also some useful loop information on the Wikipedia site.

In all, I think I'm missing out (so far) on a whole range of antenna experiments!

SAQ (17.2kHz) transmission Dec 24th

The following is from the SAQ (Sweden) website:

We plan for a traditional transmission on Christmas Eve Monday 24 December. We plan to start the transmitter at 07:30 UTC and will be on air a few minutes later. A message will be sent at 08:00 UTC. The frequency is 17.2 kHz CW.

 QSL-reports are kindly received:

 QSL reports can be given via:

- E-mail to: info@alexander.n.se
- or fax to: +46-340-674195
- or via SM bureau
- or direct by mail to: Alexander - Grimeton Veteranradios Vaenner, Radiostationen, Grimeton 72, S-432 98 Grimeton, SWEDEN

Note: SAQ is a member of the Swedish Amateur Association (SSA) and "QSL via bureau" is OK.

First on-air testing of the Tenbox TX

This evening, with little sign of F2 propagation, I ventured out to test the range of the 10m Tenbox TX as it is currently. For the TX antenna I used the coax up to my 10m halo as a vertical tuned with the Elecraft T1 ATU. At the RX end, in the car, I used the FT817 with a small base loaded mag-mount.

Tenbox AM TXing with MP3 callsign message on the PC

What I should have thought about was the noise on AM from street lights! When the signal is strong in the village this is no issue at all, but traveling to the next village 3km away there were several spots where the buzz from sodium street lights just killed the little signal. Both antennas are compromised, so another 3-6dB of signal level should be possible with a proper 1/2 wave antenna at each end or with a better car antenna.

Maybe this project, although great simple fun, isn't going to quite meet my needs, whereas a DSB transceiver would?  Receiving the DSB signal as SSB and the improvement over AM will be around 9dB with better noise immunity. However a simple direct conversion RX would not be suitable to use (easily) with a DSB TX, whereas the AM Tenbox would be fully 2-way compatible with another identical AM unit.

Conclusions so far
(a) 6-10dB more may be needed to meet the design objectives with AM.
(b) It is worth repeating the very same test now using a DSB TX with the same power to compare.

The first Tenbox Schematic

The breadboarding of the Tenbox 10m AM transceiver for local cross-town night-time nattering is almost complete now, with just a receiver audio amplifier to drive a loudspeaker to be added. Power output is a conservative 250mW AM carrier (peak power around 1W).  The first schematic draft is shown here, but as always I warn that I may have forgotten to correctly label some parts and the values may change as the circuit is further developed. I hope to road test this over the weekend going out in the car with a mag-mount antenna whilst AM beaconing with the rig from home. As with WISPY, I have paralleled up 4 2N3904 transistors for the PA. This is a very inexpensive way of making a 10m PA stage! The alternative, such as a 2N3866 would be about 5-10 times more expensive.

Small Wonder Lab Kits

Dave Benson K1SWL has produced some wonderful Small Wonder Lab kits over the years including the famous RockMite transceivers, but he has decided to slow down a bit and get back to enjoying the hobby as a hobby. I think we don't realise just how much work is involved in a small ham radio company producing and supporting a range of kits. Dave's point about technical support and repairs rings bells with me: I get around 5-10 questions a week from people interested in my website projects and I am not even selling kits!

This was the notice on his website last week:

"Folks-

I took a ‘leap of faith’ in 1996, leaving the corporate world to undertake ‘Small Wonder Labs’ as a full-time venture.  Since then, it’s been a great experience.  I have to face facts, though: I’m getting older. The shortcomings in vision can be overcome with close-up glasses. More troublesome, though, are the muscular issues from spending hours a day at the computer, or with my head down, sorting parts into bowls.

Over the years, I’ve assisted countless customers with no-questions-asked replacement parts and troubleshooting advice. The issue of repairs has been problematic, though.  While no one really objects to paying $50/hour to have a $1000 rig repaired, that’s not true of a $50-100 kit. I’ve had some good people doing repair work for me, but it’s just not economically viable. Neither can I do the work in a timely manner. Therefore, and effectively immediately, I will not be accepting returns for troubleshooting/repair.

It’s not clear to me at this point if I’ll release any additional product offerings. Although I love the creative process involved in a new design, everything that follows is now just ‘work’.   Along the way, I lost the ‘hobby’ aspect of ham radio. I have not been on the air in almost 5 years. I want my hobby back!

I’ve finished our home here in the woods of New Hampshire, and it’s time for me to move on to other interests.  I’ve still got a garage/barn to build, a garden that grows larger each year, and a wealth of outdoor activities I can’t seem to find the time for. Retirement is clearly not for the faint-of-heart!

I’ll continue to sell RockMites forever, apparently.  Demand is still brisk, with more than 8000 of them out there so far. Ongoing activity for the RockMite as well as support for ‘legacy’ kits occupies me for 2-3 hours each day.  At this stage of my life, that’s ‘enough’.

73- Dave Benson, K1SWL

19 November 2012"

ARRL 10m contest (48hrs Dec 8-9th)

A reminder that the ARRL 10m contest is on next weekend (not this) over the full 48 hours Dec 8th and 9th. As conditions on 10m are pretty good right now this will be a good chance to work a fair number of US, Canadian and Mexican states and provinces, even with QRP levels in CW or SSB. I'm away on the Saturday but hope to be on for the Sunday.

Cutting big pieces of copper laminate

When I was working I had access to a guillotine to snap out large pieces of copper laminate to convenient sizes for project breadboards. Being retired I no longer have this method to hand. SO, I asked a question on the GQRP Yahoo group this evening to find out what other people did. Several suggestions but the favourite is "scoring and snapping", summarised by the post from Duncan G4DFV which I have reproduced below.

"My method of cutting large pieces of copper laminate:-

• Place a steel rule along a previously drawn line on the board where you require to cut.
• Pressing down firmly on the rule, using a stanley or other utility knife, score along the line.
• Repeat the scoring in the same cut for perhaps 10 times, then
• looking at the edges of the board, you will see each point where the
• scoring starts and finishes. 
• Carefully mark these points over on to the other side of the board and  
• place the rule exactly along a line between these points and score as before.
• After about 10 scorings, place the board on a flat surface such that the
• scored line is on a straight edge.
• Holding the board down with one hand, press down over the straight edge with the other.
• The board should break cleanly along the scored line.
• Any uneven/rough edge can be smoothed with sandpaper.

Duncan G4DFV"

Tenbox TX progress

Good progress today with the transmit side of my Tenbox 10m AM transceiver.

The series  modulator was breadboarded a few days ago, so today I built the 3rd overtone oscillator, the buffer and the modulated PA stage. Results were as expected with around 50-60mW of clean well modulated AM available at the output. With a single linear amplifier with around 10-13dB gain (easy at 29MHz) this will take me into the 500mW-1W carrier level, which is my design aim. As I did not have a suitable 29.05MHz crystal (anyone know where these can be obtained cheaply?) I used a 28.500MHz one on a dummy load. With this frequency, any range tests will have to be done at night to avoid QRM to SSB stations.

When the linear is added , maybe even before then, I'll do a local "drive around" test with the TX on "speech beaconing" mode (using an MP3 file on the PC) and with the RX attached to a mag-mount antenna on the car. This will establish the useable local coverage.  Assuming this power level is OK, I'll then complete the full design on a tidy breadboard and publish the initial schematics on my blog and website. After that, a PCB may be in order and a neat enclosure.

This project is great fun: a simple, straightforward and easily reproducible design and a project that will be useful at the end. Much more fun than working DX with 400W and a 5 el beam in a contest with a £5k commercial HF transceiver.  Honestly, I'm having a real ball with this.

10/20W versions of popular transceivers

In the Japanese home market, several of the transceivers available in the USA and Europe are available in lower power versions too. For example, the IC7000 is available as a 50W version and a 20W version. Prices aren't always lower though. For example on the www.icom.jp site, the IC7000S (20W) is available at 168000 yen, the same price as the 100W radio.

The reason these lower power radios are not available outside of Japan is clear: lack of sales volumes and lack of the necessary approvals. It is a pity that the major dealers like W&S and Martin Lynch don't offer to import these on request though if they met EMC specs as I can imagine a reasonable market with QRPers with a bit of advertising: they have enough space in RadCom and PW after all!

How to avoid expensive calls to 0870 numbers

The website http://www.saynoto0870.com/ is a useful resource in the UK if you are looking for a lower cost, or even free, way to contact companies such as Virgin Media or Dell where an expensive 0870 call make be needed.  I get infuriated when big companies keep me waiting on an expensive call saying things like, "your call is important to us" then waste the next several minutes with drivel.

Most of these alternative numbers get in "via the back door" and work on the assumption that you will be transferred internally to the correct department. It may not always work, but if you want to save a few pounds it is worth a go.

CQWW CW - guess who forgot!

Julian G4ILO has posted a piece on his excellent blog about the CQWW DX CW contest this weekend. Well, yesterday was my wife's birthday and we had family here and today I did my tax return. In the process I managed to miss this contest completely! For some reason I thought it was NEXT weekend. Never mind, there will be other occasions to work the DX.

The hazards of LF operating

On the LF reflector there was a salutary message from Mike G3XDV today.  Doing some 136kHz tests overnight his loading coil caught fire melting his flat roof extension!

LF amateur radio can be very dangerous as extremely high voltages and/or high currents can be generated with even quite modest powers because of the electrically short antennas. This is one reason why I stick to QRP(ish) powers on 136 and 500kHz.

See Mike's post:

Damage to the G3XDV loading coil ....and roof! See http://g3xdv.blogspot.com

"I am currently off the air following my loading coil catching fire and damaging the house. I have had to take my mast down to allow access to the builders who are repairing the damage. Fortunately I was insured.

Hopefully I will be able to receive before Christmas and transmit again some time in January.

Details and pictures are on my blog at:http://g3xdv.blogspot.com

Mike, G3XDV"

This picture (linked from Mike's blog) shows the damage.It begs the question of how readily will an insurance company pay up when an amateur installation fails?

More 10m (28MHz) Projects

With the Tenbox coming along just fine - I should have a completed breadboard version on-air this week - I am beginning to think that I could spend nearly all my free time designing different ideas for this, my favourite, band!

Here is just a brief list of some of my 10m ideas (all do-able with some time):

• 10m QRP AM transceiver (Tenbox)
• 10m QRP DSB transceiver
• 10m pocket SSB/CW "holiday" receiver
• 10m mixer-VFO controlled CW transceiver
• 10m compact portable antennas for mobile and hand-portable
• 10m VXO controlled QRP TX
• 10m phasing SSB transceiver (10W)
• 10m beacon RX
• 10m test box (power meter, ATU, SWR bridge, FS/mod meter)
• Modules for 10m rigs (VXO, mixer-VFO, LPF, TX strip, DC RX, AM modulator, audio power amp etc)

Now, as I like to do so many different things in this exciting hobby - including on-air operating some times! - it is unlikely all these will get done anytime soon.

What occurs to me, if I had the time, is that a mini-series in a magazine like PW or RadCom entitled "Ten Projects for Ten Metres" would be a nice idea. 10m is one of the best bands for homebrewing as layout is not too critical, as long as sensible RF rules are followed, antennas are small, superb DX is possible in the better years and Es DX possible for 4-5 months every year, local ranges are useful for nattering across town. All in all, this band has SO much to offer.

A 2m AM calling frequency

At the recent RSGB Spectrum Forum Meeting (Nov 3rd 2012) the ongoing matter of an AM calling/working frequency was raised. At issue is why our national society, which is there to help and support ordinary experimenters like you or I, seems to be totally against putting a 2m AM frequency properly in the UK band plan. 144.55MHz is the frequency of choice.

This is what appeared in the minutes:

"7.7 G-QRP
Report accepted

Listing of an AM centre of activity frequency in the Band Plans
It was noted that this has been raised previously with no success. It was suggested that a “custom and practice” approach would be the only way of moving forward i.e. identify a frequency, use it and make it known."

Excuse me dear Spectrum Forum members, but this is stupid!  You have centre frequencies for all manner of other modes, but not AM. So, why not just print these words in the bandplan? :-

144.55MHz   AM calling frequency and centre of AM activity

I am not one to get easily irritated, but the RSGB stance on 2m AM is beyond belief.

Taxing times

Today I'd planned to finish the breadboard TX of the Tenbox 10m AM transceiver and do some range tests locally. The plan was to put the TX on at home with a PC voice recording and drive around with the FT817 and the Tenbox super-regen to see what sort of range was reliably possible.

Instead, I started to do my annual HM Revenue and Customs tax return, a task I hate doing as so much form filling is needed and lots of bits of paper have to be found in order to fill it all in. I do mine online, so the deadline is the end of Jan 2013. Starting at about 10am it took me until 4pm to complete, not because of the complexity of my affairs particularly, but because I couldn't find all the bits of data I needed. On their website they have a nice picture of a guy smiling away whilst filling in his form online. I spent about 6 hours pulling what little hair I have left out!  A reminder that the deadline for online self-assessment tax returns in the UK is Jan 31st 2013, or you get a fine.

Anyway, job done. Yet again I owe money - why do they never owe me money? - and will pay up in the next few weeks. So, a boring, tedious, annual task done and this week I can return to the interesting amateur radio project stuff.

Simple TRF based AM radio ICs

Many years ago when my sons were little I made them a couple of Medium Wave AM radios using just a ZN414 3-pin TRF receiver IC. It worked very well considering how simple the circuit was using just a small ferrite rod antenna and a crystal earpiece. This IC is no longer available but there are other similar parts available such as the MK484. Although I have not tried one of these as an IF stage I have no doubt they could be useful in simple rigs like the Tenbox currently under development. The advantages over a super-regen would be selectivity. These devices have input impedances of around 4Mohm so if a ceramic filter was to be used ahead of the IC a step-up transformer would be needed to minimise loss. As they only work to around 3-4MHz they would only be suitable as an IF in the Tenbox 10m AM transceiver.

A useful page I've just found on how to get the best from these simple ICs is http://theradioboard.com/best-of-the-best/mcgillis-mk484.htm.  The datasheet for the MK484 is available here.

A page showing the use of the MK484 as an IF stage in a simple 160m RX is  http://www.vk6fh.com/vk6fh/mk484radios.htm . See also http://www.youtube.com/watch?v=qdlXVKOITe4. I am told that a similar design appears in 'Radio Projects for the Amateur' Volume 4 by Drew Diamond VK3XU. 

I'm still likely to stick with a very simple super-regen RX in the Tenbox - they ARE the best in the intended application - but I may make it in a modular form so that different TX strips and RX strips can be used and compared.  I can see a whole series of simple AM designs in the pipeline, HI.

More big wheels and turnstiles

When looking around for possible homebrew designs I saw an article that appeared in QST back in 2008.  Looking at this approach I am not convinced it is easier than the conventional big wheel design though. See http://radio-amador.net/pipermail/cluster/attachments/20100107/a2f81f3e/AntenaHPOD.pdf . 

A design for a 70cm big wheel, designed to be used with a beacon, is available at http://www.qsl.net/dl4mea/antennas/bigw.htm .

The turnstile design on the EA4EOZ website

Another simple approach to a VHF or UHF omni-directional horizontally polarised antenna is the simple turnstile (a pair of phased cross dipoles that produce an almost 360 degree clean radiation pattern with about 0.9dBd loss only). These can be stacked to produce gain, as with the big wheel.

Overall, the conventional big wheel design is my favoured approach for 2m and 70cm. Whether I make my own or buy a Wimo version remains to be seen.

Another ham radio company bites the dust

Via an email from Steve G1KQH I've just heard that Snowdonia Radio Company has ceased trading completely and closed its business. If I understand correctly they closed down last year but had one last try again this year. You may recall that this company produced antennas such as the X80 HF vertical antenna which appears on an earlier blog entry last year I believe. I erected and used one and it worked very well.

This is sad news as it was a small UK company making good products for the amateur market. Clearly the market is not big enough to support the volume of trade they had and all their commercial overheads. One wonders how many other small companies can make a success in our market unless they get major publicity in the big magazines or have a good website that attracts a world-wide audience of potential and actual buyers. I cannot recall SRC advertising too widely: maybe this was their problem - getting a critical mass of customers who told others and came back for more themselves.

This was the message on their website today: 

Due to an ongoing decline in trade Snowdonia Radio Company has stopped trading.
All contact avenues have stopped.
This has been a hard decision as we only reopened in January 2012, but ongoing high costs and a rapid decline in trade have forced our family business to close permanently.
Thank you for the business over the years from Simon and Liz, and we hope to speak to you on air.
Please note that there are some poor quality non SRC antennas available, These antennas look like SRC products but are not. SRC do not make antennas for anyone else......

73,   _._

Big wheel antennas?

www.wimo.com big wheel

When I move to my new (higher) QTH on top of our local East Anglian "hill" next year I'll have to give some thought to what VHF/UHF antennas to erect for horizontal SSB/CW/digital DXing. I could go for a decent set of beams and a rotator or I could go for an alternative approach and erect a stack of big wheel antennas for 2m and 70cm. A single big wheel has a horizontal gain of around 2-3dB over a dipole but a couple will give almost 5dBd, which is similar to an HB9CV beam but without the hassle of a rotator and with almost 360 degree coverage.

For my sort of (occasional) 2m and 70cm DXing the big wheel may be a suitable solution. I have around 6 months to sort this out, so no rush, but I'd value inputs from people on this. Have you used big wheels? How effective were they?

Incidentally, even from my old QTH I've worked all sorts of decent VHF DX with just a halo and a few watts QRP in contests, so a lot depends on how prepared one is to wait for lifts or big contest stations to work. Clearly if the aim is to work 600-700km under flat band conditions then 100W and a largish beam are almost essential. I'm not entirely ruling such a station out of the question, but it would be a big change from my usual QRP, so pretty unlikely.

A photo in QRP Basics (2nd edition)

My wife has bought me a copy of QRP Basics (2nd edition) by G3RJV for Christmas. It came this week so we opened the pack to check all was well, before putting it away for a month.

Imagine our surprise when we spotted a photo in it of me with our grandson (when he was very young) at my operating table.  He is the little lad (now 5) who was tapping out CW on one of my YouTube videos and playing with my audio kit on another. As I never did manage to get either of my two sons interested in ham radio, I'll be lucky to get any of my grandchildren interested, but I shall try.  Regarding the rest of the book, I'll let you know on Christmas day after reading it with a minced pie in hand. As it is written by Rev George Dobbs, I am sure it will be another excellent book about QRP.

10m local range?

With the 10m AM Tenbox design coming along nicely I'm reminded of the fun we had in the early 1980s with 10m FM using converted CB rigs here in the UK. Using a converted CB radio with 4W FM into a vertical half wave antenna I was usually able to make contact with similarly equipped stations up to around 25-30 miles away pretty regularly. Certainly within a 5 mile radius signals were fully quietened, even to mobiles.

So, I am wondering how I'll get on with 0.5W of 29MHz AM? My expectation is that with a similar antenna (1/2 wave vertical - I currently use a horizontal halo) I should be able to cover 3-5 miles without too much problem. I'm wondering what sort of ranges people achieve with AM CB radios (WITHOUT add-on PAs!) where this mode is legal?  Running a few dB more power is no problem if required of the Tenbox design.

When 10m is wide open it is possible to work thousands of miles on FM but I always found that the competition was too great and therefore the mode is not well suited to DXing. The aim of the 29MHz AM Tenbox is just for very local communications and definitely not for DX working. In my mind I see the Tenbox being a modern version of the old Heath HW19 (the Tener) rig - see the image and data on the Rigpix page

WISPY 10m WSPR beacon video

A few people have requested a video of WISPY, my QRP WSPR beacon for 28.1246MHz. This video shows the TX beacon only. I have a companion RX breadboard that works well and at some point these will be combined into a small 10m WSPR transceiver.

Tenbox 10m AM RX video

It is hard to contain my enthusiasm for simple transceivers and super-regen receivers! This video shows just how well the RX breadboard for the little Tenbox 10m AM transceiver works. 1uV (-107dBm) is a very good signal and it will still detect a well modulated AM signal at -120dBm. Selectivity is not good with this type of receiver, which is the main drawback. However for its intended application - a simple transceiver for local nattering across town - it should be fine. Some people use super-regens as the IF stage of AM receivers. If a filter is added ahead of the super-regen IF this overcomes the selectivity issue but makes the RX design more complicated.

Tenbox 10m AM rig - a bit more

Although I had little time today, I experimented with adding varicap tuning to the Tenbox AM transceiver's RX section. Only problem was I had no varicaps, so tried using a few different diodes and a transistor as a varicap. 1N4148 and a Germanium diode reverse biased hardly produced any change in capacitance going from 2-12V. I know a 1N4007 works quite well but could not find one. Then I used a 2N3904's base-collector junction and got a few pF of change. In the end I just did as I did in the Sixbox and used a fixed capacitor in series with a 365pF polyvaricon tuning capacitor. This moves the RX frequency as much as I need at around 2MHz maximum.

2 countries worked on 500kHz with JT9-1 mode

Well, the JT9-1 test QSO with G3ZJO was a total success and completed in around 10 minutes this evening. Later, I called CQ on JT9-1 and got a reply from OR7T in Belgium who is 334km away. We worked, exchanging reports and 73s but I am not quite "all with it" with the sequencing of reports, R, RRR etc in JT mode exchanges.I am learning, HI.

G3ZJO in QSO with G3XBM this evening on 500kHz

The WSJT digital mode JT9-x is certainly an interesting mode. There are a few bugs in the code still, and more bugs in the operator using it (me!) but I am sure to use this mode more in future on 472kHz and 136kHz.

500kHz JT9-1 test this evening

G3ZJO and I have reported each other's 500kHz WSPR signals and each managed to get reports from close on 1800km away but, despite being only 50km or so apart we have yet to work each other on MF. This evening we are going to attempt a WSJT mode QSO using JT9-1 mode with 1 minute TX periods. I'll report back later how we get on!

More Chromebooks

The new Acer C7 Chromebook on the
www.cnet.com site

A few weeks ago I mentioned the Samsung Series 3 Chromebook which is available in the UK for £229. Now I see there is a new entry, the Acer C7 Chromebook which retails for just £199 here and $199 in the USA. This sports a 320GB hard drive and, like the Samsung, a high resolution 11.6 inch display.

The main drawback (or is it an advantage?) of a Chromebook is that it uses the Chrome OS and depends a lot on cloud based applications, although quite a lot of applications work off-line too these days.

Certainly for a second PC at home and on the move it has to be a good bet.

472kHz WSPR this evening

After the CW QSO and 500kHz WSPR TXing this evening I switched over to 474.2kHz USB dial WSPR receiving, whilst I watched "Homeland" on TV (BTW, this is a truly excellent US drama series - I don't usually like US dramas). Good signals coming through from the usual suspects, HI. The weaker signal at the bottom of the image is DF2JP.

474.2kHz WSPR this evening

It sounds like the first UK access to the 472-479kHz band will be for old 500kHz NoV holders, which includes me, on Jan 1st 2013. It is NOT likely the band will be generally available in the UK at that time, but some time later. Even the 500kHz NoV holder access to the new band is not yet certain on Jan 1st 2013. Watch this space!

CW QSO with M0FMT on 500kHz this evening

After the usual reports from all over the place on my 50mW ERP 500kHz WSPR I took a listen around for some CW stations this evening. G3XIZ was calling CQ and listening on 80m crossband, but then I heard Pete M0FMT not too far away in Hitchin calling CQ. He heard my reply and gave me 529 report. He was about 549 with me deep in the noise that remains on the band. A few days ago this QSO would have been impossible because of the local noise here. The offending noise source (central heating controller SMPSU) is switched off!

Barbados on 10m QRP

8P6BX in Barbados

Whilst looking for QSOs with Lesser Chirpy on 28.060MHz this afternoon I heard Ron 8P6BX in Barbados calling CQ. No go with 70mW so I turned on the FT817 and worked him with 5W getting a 569 report. He was running 3W and was peaking 589 with me. It was a nice, solid 2-way QRP QSO on CW.

Autumn projects - an update

Well, I don't seem to be getting on too well with my autumn project list! The 472kHz transverter got finished, as did the WSPR beacon rig for 10m. I also managed some VLF earth-mode work. However, I've still to get back to the 481THz (lightbeam) over-the-horizon tests using the new higher power Phlatlight 5W LEDs. Neither have I rebuilt my 10m halo or erected a proper RX antenna for LF and MF. Mind you, I've added a new project, the Tenbox 10m AM transceiver, which is progressing quite well so far.  In the end it doesn't matter what gets done and when as long as I'm enjoying the hobby and experimenting with simple ideas.

Burwell Steven's Mill © Copyright Rodney Burton and licensed for reuse under this Creative Commons Licence.

Around the middle of 2013, if things go to plan, we are moving home to a bungalow in the same village which is located on the "hill" (this is a relative term in East Anglia!) next to Burwell windmill and museum. The windmill has just received a National Lottery grant and should be fully restored to full working order with 4 sails. This will be about 20m from our front door! I'll expect to be asked to do a "windmills on the air" weekend, HI. Burwell Museum is really something quite special and well worth a visit.

With what will be a much better VHF and UHF take-off I will be tempted to get much more active DXing on 2m, 70cm and 23cm from the new QTH. This is likely to bring a whole new set of challenges.

Lesser Chirpy spans the Atlantic (10m QRP)

My 28.060MHz ultra-simple QRP transceiver was copied in the USA this afternoon. K3MM (Maryland) reported me on the Reverse Beacon Network as 7dB S/N at 15wpm on 28.060MHz. K3MM is in FM19JH which is 5886km away.

Initially I was unable to hear any stateside stations to call for a QSO. Still, the rig has now been copied across that big ocean! Power out into the halo is around 70mW.

VE2TH was coming through OK with 5W and might have been workable but the band faded out.

Testing the Tenbox on 10m AM today

Today I wanted check how good the Tenbox 10m AM receiver (part of the intended transceiver) was in real use as opposed to measuring it on a signal generator.

So, I set up my FT817 on 10m AM TX on the lowest power setting, which is around 150mW carrier, and fed this into a makeshift vertical tuned with the T1 ATU. Using my PC, I made a short message "G3XBM testing on 10m AM" that I played in auto-repeat.

I then went for a drive locally with the little super-regen RX in the car being fed from a vertical mag-mount antenna on the car roof. The only antenna I had was an ATX15 base loaded whip for 15m, so I pushed a few sections in to make it resonate on 29MHz.

Results were encouraging. Out in the car my 150mW AM TX beacon message could be copied out to about 2 miles away, although this was limited by QRM from W2VW (!) and VE3OWV (!) who were coming through with 59 signals on the RX on 29MHz AM. When they dropped carriers copy was fine. It's fascinating to think my 150mW AM signal was having QRM from 5000km away!

A super-regen is not really suitable for use when 10m is wide open, like it was this afternoon. Nonetheless I was able to copy stateside stations on 10m AM on a short base loaded mag-mount pretty well. For its intended purpose as a local across town natter box, I think the Tenbox is going to be fun. With 6dB more power out (my aim for it) it should be certainly possible to work G6ALB 3km away in the next village.

The next stage is now to build the TX part and test this.

After the noise: 160m CW QSO

Following my small successes last night battling my local man-made noise sources, this evening I managed nearly a full QSO with GW0IRW on 160m CW when running 5W to my vertical coax to the 10m halo. The noise level is now low enough to sensibly copy stations on 160m, which I've not been able to do for months at night.

I am now monitoring 474.2kHz WSPR hoping to improve on my reports now the local noise floor is much lower. SM6BHZ is already coming in at a respectable -14dB S/N. He is usually pretty strong so it will be interesting to see how many others come through this evening.

Winning the noise battle a step at a time

This evening I've been trying to track down various noise sources that have been making reception on MF and the lower HF bands all but impossible in recent weeks. I'm pleased to report a couple of successes.

My first "trap" was the 12V Netgear AD6612 AC-DC adaptor that feeds my Virgin Media internet superhub. This little terror was producing an S6-8 noise floor on many of the lower ham bands. I tried ferrite chokes in the leads but to no avail. Fortunately I had an old Linksys 12V supply with the same sort of rating and 12V plug. Swapping the PSUs over and, guess what, the lower HF bands were much quieter once again.

At 470-500kHz though I still had an S8 noise floor, so there was another candidate noise generator around. Switching everything off in the house the noise floor dropped, so it was in the house. In the end I tracked this down to a Salus mains powered controller that receives wireless signals from the central heating roomstat. Turning this off and, guess what, 470-500kHz goes much quieter too! This unit is quite close to my antenna wire and must have a noisy SMPSU inside. Luckily we tend not to have the central heating on in the evening so all I have to do is turn off the Salus wall unit controlling the central heating boiler and I can, I think, go back to better reception on the MF bands in the evenings.

In 30 minutes I've reduced the noise floor in my home considerably from LF to at least 10MHz. This goes to prove that with a little bit of detective work we can do a lot to overcome many of the noise issues plaguing us these days. Both the Virgin Media superhub and the Salus unit are new (less than 6 months old) so this also explains why the noise issue was not such a problem last autumn and winter.

If you have a noise problem then I recommend you do some detective work and very good luck.

Coils for projects

Many of the old TOKO range of coils are hard to find these days but an alternative source for many of these is now available from Spectrum Communications in the UK. See http://www.spectrumcomms.co.uk/Components.htm for more details. If you are a member of the GQRP Club, many of these are available through its excellent club sales. An example, the 45uH coil specified in my 472kHz transverter is available from the above suppliers.

Spectrum also sell a useful range of crystals as well as some of the harder to find, once common, MOSFETs.