Heathkit kits again?

The Southgate amateur news page carries a story that Heathkit may be about to start the production of kits again after a break of many years. This would be excellent news. Heathkit used to produce world class kits that were in a class of their own with first class instructions. Let us hope they decide to restart amateur radio kits as well in due course. In the amateur radio field Elecraft are the nearest.

500kHz

With the autumn season not too far off I am turning my thoughts to 500kHz and 136kHz again. This weekend I hope to return to 500kHz WSPR as GM4SLV is testing his new 500kHz antenna and ATU. After that it will be my turn to improve the ERP on 136kHz with a new PA, ATU and antenna.

Antenna folklore

From the LF-reflector and very true.

Antenna engineers use to say about design goal limits of antennas:

    Small
    Efficient
    Wideband

Pick any two (meaning you can't have all three...).

73   Clemens   DL4RAJ

Inter-G 10m DX with 5W WSPR

In the last 24 hours, as well as some excellent long distance DX, I've been surprised by the 10m reports from stations within the UK. For example G4CUI in IO93 and G6BHS in IO81, both around 170km. These are not one-offs as exchanges with G4CUI are common at almost any time. I must keep a record of all the QTH locator squares I get reports from on 10m and 6m WSPR from within the UK. WSPR is an excellent mode for "sniffing out" openings.

Chile on 10m WSPR

Just exchanged WSPR reports with XQ6FOD in Chile at 12285km on 10m this evening at 2054z. At first I thought this was a bogus report but checking on QRZ.com the call is genuine. I think this was Es linking into some TEP F2 propagation as I was getting good reports from Spain.

Good Es DX on 10m

This afternoon I put my WSPR beacon on 10m for a while and was surprised how wide open the band was. Strong Es signals from across Europe and N.Africa plus a couple of excellent reports from R9SA in LO71 square at 3661km to the east. I'm wondering if the band will open up across the Atlantic today. Even with 500mW I was getting very good reports. Reports from OY1OF suggest even 500uW would be enough for a report.

Best results yet on 8.76kHz earth mode

8.76kHz earth mode signal in 45mHz BW at 6km

This morning I slightly changed my VLF low input impedance tuned preamp by increasing the tuned circuit Q and gain of the first stage by around 6dB. After lunch I did a test at 6km from home to see what effect this had on the S/N of my 5W beacon. In a 45mHz bandwidth (previously 11mHz) I was getting a signal around 18dB S/N using Spectrum Lab on my 80cm square loop on the ground. With an earth electrode antenna the signal was marginally weaker and the noise level higher.

My signal is the steady carrier (with a 2min ID break) at 8.7605kHz. The large wobbly line is interference, but who or what is the signal at 8.754kHz? This is rock steady and appears to key on and off every 5 minutes. It looks like some sort of control signal, or is someone else near Cambridge testing?

Rural Suffolk - England at its best

We are blessed with a wonderful variety of scenery and plenty of still quiet rural countryside to enjoy despite our cities being crowded. This afternoon my wife and I enjoyed a ride through rural Suffolk in East Anglia where we stopped at a number of delightful small churches.  There is a lot to be grateful for in an English summer with a gentle breeze, warm sunshine and the sound of swallows, woodpeckers and bees overhead.

Wispy WSPRs

Overnight I was looking for MS propagated WSPR signals on 10m. There were a few early morning decodes as well as plenty of evidence of MS bursts which were too short and too Doppler shifted to permit successful WSPR decoding.

Perseid meteor shower

Overnight tonight the Perseid meteor shower will peak with some dazzling displays in the early hours of Saturday morning if the sky is clear. With luck, MS conditions will be good on 10m, 6m, 4m and 2m with some long bursts. Not sure what band(s) to monitor but may see what can be heard/seen on JT6m on 6m.

Inside a QRPer's brain

G3XBM's brain!

Today I had my brain scanned for scientific research. For several years I've volunteered as a guinea pig at the Centre for Speech, Language and the Brain at Cambridge University.  It involves doing the occasional language test and about once a year having an fMRI scan whilst doing some task involving language. The university has its own MRI unit for medical research. The whole MRI thing is painless and is actually rather relaxing, especially when they are doing a full scan and the machine is vibrating which is like having a massage. If anything untoward is seen in the scans they inform your doctor, which is good. Let's hope that it looks OK. Certainly it looks much like the one I had done a few years ago.

The purpose of the research is to better understand how the brain functions and they hope this will help with people recovering from strokes.  It must be so rewarding to be working in this field either as a PhD student or as a post-doc researcher.

6km DX on 17.52kHz earth mode

My 5W QRP signal at 17.52kHz is clearly visible at 6km

Last evening I continued the earth mode tests at 17.52kHz by going out to the test site 6km from home and looking for the signal with a variety of antennas in QRSS3 and with an interrupted long carrier transmission.

No copy was achieved using QRSS3 and Spectran. However, using a continuous carrier with a 2 minute ID break I got extremely good copy (about 6dB S/N) with Spectrum Lab in 37mHz bandwidth with the horizontal 30t loop but no copy on the earth electrode antenna parallel to the road. Moving the loop 10m away from the road resulted in no copy, as did mounting the loop vertically or a few metres above the ground.

It would appear that at 17.52kHz it is easier to detect the signal at distance with a loop than with an earth electrode antenna whereas at 1.095 and 8.760kHz either scheme works. Perhaps someone who understands the theory will be able to explain this.

My next test is to repeat these tests at 137kHz to see to what extent 137kHz is aided locally by utilities assisted earth mode. At the test site 6km away I can see how strong the signal is with tight coupling into the ground at the roadside, and with an E-field probe some distance away from the road.

3.6km with 17.52kHz earth mode

This morning I did an initial test at 17.52kHz using my 5W QRSS3 TX and earth electrode TX "antenna".  A test at 3.5km from home showed the signal ~20dB over noise (0.73Hz BW QRSS3) using the 30t loop on the ground and with a 1t loop (about 20m sq) laying in the road (see attached Spectran screenshot). Signals were also copied with the earth electrodes parallel to the road but weaker than on the loop. They were also copied weaker still with the RX earth electrodes strung across the road. Signals are definitely coming through the ground/utilities with no evidence of any radiated signal and they are every bit as strong (or stronger) than at 8.76 or 1.095kHz.  However, at another test site 4km from home where I usually manage to copy 8.76kHz QRSS3 reasonably well there was no sign of my 17.52kHz signal either with the 30t loop or the earth electrode antenna. No idea why.

Later today I may try the 17.52kHz test at my 6km distant test site with a long duration carrier, although I suspect I may copy it in QRSS3, which I'll try first. I may also try a test using my 80m sq vertical loop as the antenna at the TX end, although I don't expect any great range by pure induction.

1.095kHz earth mode test at 6km

1.095kHz earth mode signal at 6km

Today I repeated the earth mode (through the ground) "long carrier" test of 17.7.11 this time at 1.095kHz rather than 8.760kHz. The same test location was used in the fens not far from the River Cam. This is now a very long way from home! As before, I got my wife to cut the carrier for periods of 1 or 2 minutes to positively identify my signal. I need to automate this so she can continue to do the gardening.  4 different receiving antenna arrangements were tested, using my low impedance MPF102 tuned preamp into the PC:

(a) an earth electrode pair parallel with the road,
(b) an earth electrode pair diagonally across the road,
(c) a single turn loop in the road, and
(d) a 30t 80cm diameter loop at the edge of the road. 

Best results were with (a) and (d). With (b) there was no detectable signal.  At 1.095kHz the signal was again around 10dB S/N in 11mHz bandwidth on (a) and (d) and marginally weaker on (c). This is a similar result to 8.76kHz although I was expecting the signal to be stronger at this lower frequency.  I'm now tempted to do an earth mode test at a higher frequency, possibly 17.52kHz which I can still see with Spectran and Spectrum Laboratory and I can derive with my 4060 divider circuit. Using earth mode I believe I'll still be legal as very little radiated signal can be present. The image shows the signal with the RX earth electrodes parallel to the road, i.e. set-up (a), at a distance of 6km from the home QTH where the TX was running 5W into 20m spaced earth electrodes.

Using Spectran to listen to HF CW

Usually free Spectran software is used here to see VLF signals when doing my earth mode tests. However it also makes a very useful add-on to the FT817 as an adjustable width audio filter. Select the NDB settings and then use the filters (adjustable edges with right and left mouse buttons) with the menu on the left set to "BandPass". It is useful on SSB and on CW and allows the bandwidths to be screwed right down to as low as need be. There is also a CW peak function which puts a narrow filter around 800Hz.

Internet data usage measurement?

Although my ISP doesn't appear to set limits on the amount of data I download, can anyone tell me how I can measure the amount of data I am actually downloading each day or each week?

The financial crisis - living beyond our means?

The financial problems that have become apparent since 2008 can be put down to individuals and nations living beyond their means. How can the US government continue with an exponentially increasing debt? Why do people crank up huge credit card bills when they have no likelihood of ever paying them off? Why do many wealthy individuals in places like Greece make tax avoidance a way of life?

What happens next is hard to figure out but we are in for a period of pain and readjustment. Just maybe the outcome, eventually, will be a good and fair one but I can't help thinking we are entering troubled times where the threat of violent revolution is not far away.  This is a time when moderate people with good judgement need to make the voice of reason clearly heard.

HF noise levels

It is sad how much the noise floor has risen at my QTH in the last few years. Listening on 160 and 80m is now almost impossible on a vertical because of the wideband noise that obliterates the band to an S8-9 level. The noise is there right through to above 17m. Thankfully 10m with the horizontal halo is still pretty clear. Apart from my experiments at VLF and LF I am now tempted to move back to the VHF/UHF bands for serious operation.

VLF beacon transmitter schematic

G3XBM's VLF 5W Earth Mode Beacon

This is the schematic of my TDA2003 5W ULF/VLF beacon transmitter used in recent earth mode tests. The frequency is derived from a 4.48MHz crystal that is divided down to either 8.760 or 1.095kHz using a 4060 IC. This is keyed in either 10wpm CW, QRSS3 or QRSS30 with a K1EL beacon keyer IC. The output of the TDA2003 is matched to the resistance presented by two earth electrodes using a tapped toroid transformer. Best DX is now 6km across the fenland near me.

Braintree LF/VLF talk slides

The slides from my LF/VLF talk at the Braintree and District Amateur Radio Society on Monday August 1st 2011 are now available on-line. BADARS is a small but active radio club in Essex and I was given a very warm welcome by the members.

10m tropo

Weak signal modes never cease to amaze me. This evening I've been exchanging 5W WSPR reports with G4CUI 173km away near Sheffield on 10m by what I presume is tropo. Running WSPR for hours on end certainly shows unexpected paths popping up from time to time. Even 5W is enough with this mode, and I assume modes like JT65.

If properly exploited by using weak signal modes like JT65 and WSPR 10m could be a great inter-G band even with QRP and small antennas. I wonder who will be the first G station to Work All Britain on 10m JT65 with QRP?

Very accurate QTH locator data

Today I found that my very accurate full QTH locator is JO02DG85VD by looking at http://no.nonsense.ee/qthmap/?qth, zooming in and reading out the 10 digit alphanumeric code. You may want to try and find yours too if you want to know distances from another station very accurately.

IC7000 versus FT450D?

As a keen QRPer I'm usually quite happy with 5W (sometimes 10W) but I'm considering upgrading my IC703 to a newer radio as it is now many years since I've done so.  My main (non-LF/VLF) interest remains 10m and 6m although I quite fancy doing more on 2m and 70cm SSB. With HF conditions unlikely to be great in the coming years (even with cycle 24 peaking soon) maybe a little more power would be useful at times. Also, improved filtering and DSP functionality could be helpful as the HF bands get noisier.

The favourites on my shortlist are either an FT450D or an IC7000 as www.eham.net reviews give both radios good scores and these are feature-rich small radios.  The IC7000 is quite a bit more expensive but adds 2m and 70cms.  I'm wondering if readers can make any recommendations please based on personal experience? The other option is to wait another 6-9 months until the Elecraft KX3 appears.

Finally, in the UK, what is the best deal on these radios? I want a supplier who is likely to be around in 3 years time, a long warranty and the best price!

Goats, rabbits and pigs

Amateur radio activity has been on hold this week as our younger grandson has been here to stay. Today we went to Wimpole Home Farm and he enjoyed making friends with the goats, rabbits and pigs. Here he is trying to get friendly with some very tame goats.

Braintree LF/VLF talk next week

Next Monday, August 1st, I've been invited to share my interest in LF/VLF with members of the Braintree Radio Club in Essex. The talk starts around 8pm and will cover my (dead simple) approach to MF, LF and VLF as well as giving some insight into the recent work in Europe by VLF enthusiasts with both earth-mode and radiated DXing. I'm looking forward to this.

40th Wedding Anniversary

40th Wedding Anniversary Guests

This weekend my wife Lis and I have been celebrating our 40th wedding anniversary with our friends and family. It seems only yesterday we were married! Time flies so make the most of every moment. This group photo shows everyone who attended our afternoon party.

G4ILO's brain tumour

Several readers of my blog also read Julian G4ILO's interesting blog. You may, or may not, be aware that Julian has recently been diagnosed with an incurable brain tumour known as Glioblastoma Multiforme Grade 4 and he is just about to start treatment to slow down its progress. A complete cure is unlikely but modern treatments can certainly help to slow the tumour growth. I'm sure you all join me in wishing Julian every success in beating this. Julian and his wife Olga have a new blog tracking his treatment progress called One Foot In the Grave which I commend to you.

6km DX by VLF earth-mode today

8.7605kHz earth-mode reception at 6km across the fens

My personal DX record for VLF earth-mode (through ground conduction/induction) at 8.7605kHz has been pushed up to 6km today using a long carrier transmission with periodic ID breaks and Spectrum Laboratory software with bandwidth of 11mHz on receive. Transmit power was 5W from a TDA2003 transmitter.

See https://sites.google.com/site/sub9khz/earthmode/vlf-xbm-blog

More VLF earth-mode tests

8.76kHz QRSS3 signal at 3.8km

Recently the water company repaired some pipes right outside our property in the road. I was informed the pipes are/were NOT metallic.

Today, just as a check, I tried 8.760kHz earth-mode running my usual 5W into 20m spaced earth electrodes just to see if the repair work made any difference to signal levels some kilometres away.

At my favourite roadside test site 3.8km from home I set up my RX and tried 2 different loops on the ground (a) my 30t 80cm square loop and (b) a large single turn loop.  Using QRSS3 the signal was copied on both antennas at the usual strength. This makes me think any "utilities assistance" is NOT purely from metal water pipes in the road.

My next planned test is to see how well an earth-mode signal propagates along one of the many fenland water channels using one TX electrode actually in the water and one on dry land. For RX I'll either use another earth electrode pair (one in and one out of the water) or a loop or E-field probe. The next couple of weeks are pretty busy with family matters, so this fenland river test may not take place until sometime in August.

Best deals in UK for phones, TV and broadband?

Just wondering what people think is the best deal currently available for TV, phones and broadband? Currently I have TV from Sky, phone calls from Sky (£25 - broadband and free anytime package with line still with BT at around £13) and 10M broadband from Virgin Media at £18. BT have offered me "up to 20M" broadband and free anytime phones for just £9.70 a month, plus £10/month line rental. This seems a very good deal. Whatever, I surely must be able to save by getting everything from one supplier.

What package do YOU have and how much should I expect to pay to get TV, decent broadband and free anytime phone (with line rental)?

6m/10m tropo with WSPR

On a few occasions recently I've had some spots at surprising distances within the UK by what I am sure is tropo on 6m and 10m WSPR. Just a few moments ago I got a -27dB S/N report from G0MGX in IO93ga at 145km with my 5W to the vertical on 6m. It is for this sort of surprise result that I find WSPR so good: when one least expects a report you get one.

UK/European SSB on Citizen's band

I understand that a recent CEPT (ECC) decision means that 27MHz SSB CB will be permitted in the UK and Europe from October. See http://www.erodocdb.dk/Docs/doc98/official/pdf/ECCDEC1103.PDF

Never mind the FT818, bring on the KX3!

Someone has reminded me that Elecraft pre-launched their new "trail-friendly" all mode QRP rig at the Dayton Convention recently. This will be a VERY sophisticated and well equipped small portable transceiver covering 160-6m with some truly astounding features. See http://www.elecraft.com/KX3/kx3.htm . Don't expect to see it much before Christmas 2011 or later.

FT818 All band portable

Some months back I posted a Photoshop created picture of a possible successor to the FT817, which I termed the FT818. This was NOT a real product but quite a bit of reaction was created, including a few people contacting Yaesu placing advanced orders!!

Such an FT817 successor has still to appear and I'm wondering if this is now likely at all, especially with the recent earthquake and tsunami in Japan. It may be worth keeping an eye on the Japanese Yaesu site as new products sometimes appear first in Japan. Despite the less than brilliant HF conditions I still live in hope for a new HF/VHF/UHF handportable from this manufacturer before the Chinese do one instead, at a much lower price.

Near miss in Iceland

Late last week we crossed a 120m long bridge on the main Route 1 road in southern Iceland 3 times travelling to and from the small village of Vik. 24 hours later this bridge was completely destroyed when the dangerous Katla volcano had a minor eruption under the Myrdalsjoekull glacier sending melted ice and water rushing down to the sea with great force. We were so close to being on that bridge. See http://http.ruv.straumar.is/static.ruv.is/vefur/Katla_fyrir_net.wmv .

When Katla explodes seriously (it is overdue and has been stirring recently) it is likely to cause massive devastation in South Iceland and the fallout may well affect the world's weather for years (a bit like a nuclear winter) as was the case in past large eruptions. Be afraid, be very afraid...

Sunspots on the slide

Every day that passes I am more convinced than ever that the peak of cycle 24 has already passed and we are now on the downwards slope. If correct, this is one of the weakest cycles ever. It is still possible this is just a blip, but I think not.

Iceland

Currently on holiday in Iceland enjoying some spectacular scenery on the journey around the island by car. No radio gear - just enjoying the landscape, birds and people.

Meccano Magazine - free online archive

Today I rediscovered an old Meccano Magazine from 1942 in my drawers. Back in the 1950s the Meccano Magazine was a highlight I looked forward to receiving with news of new additions to the Hornby Dublo 00 gauge trains and new Dinky toys. Even this wartime edition has lots of interest in it. The size was obviously reduced in WW2 to conserve paper as it was considerably larger when I had in in the 1950s. The entire series of Meccano magazine is available free online. See http://meccano.magazines.free.fr/ .  Individual pages or whole magazines are available as pdfs.

Bitsbox supplier

A recent post on the GQRP Yahoo group alerted me to Bitsbox which looks to be an excellent UK supplier with decent prices and delivery charges. They stock a lot of useful parts. I have to place an order for some new parts for autumn/winter projects and intend to give them a go.

6m WSPR

For the last few weeks I've been on 6m WSPR when busy doing other things in the home. I run 5W into a V2000 vertical. Almost every evening I exchange reports with CN8LI in Morocco but there is very little WSPR activity at "interesting distances" on this band. By this I mean stations in the USA, Canada, South America and the Caribbean. The 6m Es multi-hop super DX season only lasts a few months and now is a great time and WSPR a good mode to exploit it.

BTW last night G4ENZ was getting decent reports from Morocco when using just 1mW with WSPR at over 2000km.

Incidentally checking inter-G paths on 6m is also fun using WSPR. These tropo distance spots are often accompanied by Doppler shifted multi-path interference from passing aircraft. It is even worse on 4m and 2m I suspect.