19 Feb 2014

OFCOM - sub-8.3kHz and around 73kHz in the UK

You may recall that several weeks ago I contacted OFCOM to clarify (1)  the legality of no-licence operation in the UK below 8.3kHz (band is unallocated) and (2) operation around 73kHz with limited ERP (licence exempt). 3 emails later, I have STILL to receive a response. I wrote again today hoping for a reply this time.

The same issues are to be raised by the RSGB on March 13th at their OFCOM liaison meeting.

It now looks like the address I was given was a DEAD email address  Today I contacted Spectrum.Licensing@ofcom.org.uk  and hope, this time, to get an answer.

First Ultimate 3 kit package arrives

Yesterday, the first of my 2 orders from Hans Summers arrived from Japan.  I'll wait until they both come before opening and, depending on my health, may wait a while before building. I am still pretty clumsy, so it may be advisable to wait a while.

The kit, with GPS timing, is good value for money. It came well packed in a small cardboard box as you can see.

20 unique spots with15m baseline earth-electrodes on 474.2kHz WSPR

Since improving the match on the 15m baseline earth-electrode "antenna" on 474.2kHz WSPR, the number of UNIQUE spots of my transmissions has jumped to 20 from 9.  No further DX (yet) but my signals that were once below the noise threshold for some are now above it, so copyable. Signals are about 3-4dB stronger  generally.
UNIQUE WSPR SPOTS of my 474.2kHz signal using 15m earth-electrodes
So far,  I have been seen in 5 different European countries. Best DX remains DL-SWL at 701km. I expect the number of spots of my signal to increase further in the coming days. The earth-electrode "antenna" is now performing credibly now well matched.

I am beginning to wonder how the system will perform on 160m and 80m, and even 2200m  (137kHz).

Never let it be said you have no antenna for 474.2kHz - I think I have PROVED that a most basic system works!  As long as above -30dB S/N your signal should be copied, although you may have to be patient. The results above were mostly one evening only.

One of the advantages of the longer baseline earth-electrode "antenna" will be its new direction. It will be almost 90 degrees around from the current antenna so quite a different polar pattern.

18 Feb 2014

Transformer success on 474.2kHz

This afternoon I inserted a small 3C90 cored transformer between the transverter and loading coil on the 15m earth-electrode antenna. Much to my surprise the best performance (25% increase in antenna current was with a step-up from 4t to 14t implying the earth electrodes look  like several hundred ohms. Success was immediate with a first spot from M0JXM (93km) and report from G3WCB (101km) some 3dB stronger at -18dB S/N. The loading coil today (soil less damp outside?) is around 50-100uH only. The transverter runs cool implying a good match.

17 Feb 2014

More 474.2kHz WSPR success

Overnight my transmissions with the 15m baseline earth-electrode antenna continued. A couple of  reports from Holland were added to the list of spots bringing the total UNIQUE station reports to eight. The only change has been to resonate the loop with a small series inductor. This increased the loop current by about 20%.  Next to try will be to see if the 50 ohm match can be bettered with a small auto-transformer. I suspect not, but we'll see.
UNIQUE reports received on 15m baseline earth-electrode antenna on 474.2kHz WSPR




16 Feb 2014

Easily tired - stroke

One effect of my recent stroke is I get exhausted very quickly.

Sitting on the PC is OK, apart from having to correct all my typos,but anything involving physical work, or talking, rapidly tires me. As an example, today is a beautiful sunny day (8-10deg C),  so a good chance to prune some roses in the garden, except that after doing a couple I was exhausted and just had to rest! This is not the real me at all!

Even talking on our local 2m net on Monday's tires me: it is speaking that tires me the most. At least with WSPR, once set up, operating does not tire me. It runs itself and all I have to do is check all is OK and observe results on WSPRnet.

The other day I wound a 400uH coil,with taps, on a 110mm drainpipe for 472kHz ,but the effort needed was so tiring. At the moment, major build projects are out of the question until my strength and stamina return.

I do so want to get better and be back to my normal healthy self.

474.2kHz WSPR results - 15m earth-electrode baseline

I left 474.2kHz WSPR running overnight using the 15m baseline earth-electrode running vaguely E-W. Results were encouraging. Don't anyone say they can't erect an antenna for 474.2kHz! If even THIS works, almost anything is possible.
474.2kHz UNIQUE WSPR spots in last 24 hrs on
15m baseline earth-electrode "antenna"
Some stations are actually stronger on the earth-electrodes than on the conventional "wire in the air". Best DX 701km with an ERP around 5mW MAX and no conventional antenna is not at all bad. I am sure a proper Marconi antenna would be better but the earth-electrode ground "antenna" is a good compromise system when options are limited. It is totally invisible too - VERY neighbour friendly.

On the receive side, 10 unique stations copied in 4 countries. Not bad for a less than 24 hr period.
474.2kHz UNIQUE WSPR spots in last 24 hrs on 
15m earth-electrode baseline on receive

15 Feb 2014

Proposed new 474.2kHz Earth-electrode baseline

The yellow line shows the approximate 15m baseline used currently on MF WSPR.
The red line shows the proposed new earth-electrode baseline which should place the northern electrode well clear of buried pipes and wires. It should be better, but you can never be sure until you try it! I (or a friend) need to hammer in some new ground rods first at either end of the baseline wire.

Back on 474.2kHz TX

Partly as a result of damage to the Par HF antenna, I decided this morning to connect my earth electrode antenna on 474.2kHz and TRANSMIT for the first time in around 6 months. It works OK, although the baseline will be extended later. with spots exchanged with G4KPX (Ely), G3WCB (101km) and G6AVK(78km) at sensible levels. It will be interesting to see the results this evening with some sky wave. UPDATE 2230z: No sky wave reception reports yet received.

For reasons I don't understand, I have received NO reports of my signal since 1550z. I have rebooted the PC, reloaded the WSPR software,changed frequency (several times),  checked internet time synchronisation, checked antenna current, checked just about EVERYTHING.  Received signal levels of other stations are as before. The only change is it has been raining. A puzzle as if the earth-electrode was behaving differently I would have expected changes to antenna current and received signal strength. I'll leave everything running to see what happens. Or is it just that my weak signal is being clouded out by higher band noise as afternoon becomes night? I'd still expect to receive some reports, especially considering how good some stations are on RX.

Eventually I got a -31dB S/N (just copied) report at 2034z from M0EMM in IO82sq at 192km. Shortly afterwards I was copied at -23/-24dB S/N by G3WCB (101km) several times.

Maybe it IS that my signal is right down in the noise for most people a lot of the time?  If so, significantly lengthening the earth-electrode baseline is a priority (see next post).

These are the unique reports so far on the short baseline earth-electrode system up until 2150z this evening.All stations reported me many times:



Par 10/20/40m antenna - storm damage

Looking out of the window I see my Par HF antenna has come apart and is dangling on the back lawn.  I shall be unable to re-erect it until my son next visits.  In the past (before my stroke) I would have had it fixed in 5 minutes! A quick trip up a ladder. I now have to be patient.  It looks like it has broken at the 40m trap, so should be easy to mend.