The Weekend brings more 600m Spots

The Locals responded wonderfully to my request to look out for my signal this weekend plus another new Scottish station GM0UDL in the bag and G4FDD.

30/01/2010 22:44 0.503816 -29 0.000200 GM0UDL IO77vo 630
31/01/2010 21:58 0.503825 -30 0.000200 G4FDD IO93kx 191

From the Local camp G4YKE at 8Km provided a 24 Hour monitor of my signal allowing me to take a look at this close propagation thing. We are line of sight across some undulating fairly damp clay fields with a clump of trees on the highest point just past mid way which don’t completely block the line of sight. I named these trees ‘Fat Lady Laying Down’ ’cause that is what they look like, Morse modulated Light Waves and Microwaves pass down her cleavage, we know we have done it.

31/01/2010 11:30 0.503855 -19 0.000200 G4MZX IO92nd 14
31/01/2010 14:20 0.503847 -31 0.000200 G8EUX IO92md 15

So do my signals vary with propagation at 8km, only 10 Wavelengths distant? It looks like it does, comparing my signal received by G4YKE on a horizontal antenna at 8Km and by M0LMH on a 500kHz vertical antenna at 194Km seems to indicate this.

Next if we compare the signal from the Vertical Antenna of G4JNT received at G4YKE, a distance of 160Km, with that of G3ZJO at just 8Km distant it seems that, whatever the polarisation and angle of radiation from my Antenna is (it is uncertain due to its compact size and surroundings), we suffer similar changes in propagation at the same time.

 

I am not experienced enough on MF to draw positive conclusions, others may be able to say more.

2 more Stations on 500kHz

The close range stuff still continues to intrigue. Finally I have been Spotted by G0NBD and G3KAN, it was my QRSS he spotted the other evening, now he is getting good signals. I think it is too early in the setting up and aerial adjustment period to study what is happening to my signal in the first 5-6Km or so.

28/01/2010 23:36 0.503812 -28 0.000200 G0NBD IO83lk 195
29/01/2010 13:10  0.503824 -12 0.000200 G3KAN IO92nf 5

Spotted by the POLICE or was it the Palace on 500kHz

Well PA0LCE actually, one more added to the list overnight.

2010-01-28 06:36 G3ZJO 0.503838 -33 0 IO92ng +17 0.050 PA0LCE JO21nj 423

423Km, -33dB is just on the edge of possibility with WSPR.

I have also had a report of my QRSS possibly being copied at 6Km. The local distances intrigue me, inefficient antennas mean not much is copied on the band, but I would not have expected much attenuation of my signal at 5 to 6Km.

500kHz Antenna Computer Model ERP

The QRP Kids on 500kHz G3XBM and G3ZJO would hate to be over underestimating, 😀 our QRPp ERP levels.
A few days ago Roger told me he had got more sensitivity out of his Antenna Current Meter and Re – Calibrated it. Funny that, I read his e-mail with my Meter in one hand having modified it for more sensitivity.

I had a FT37-43 ring core in my meter, I struggled to get a decent reading. I have had in mind for some time to try something from the ‘unknown ring core drawer’. In fact some are ‘known unknowns’ from faulty CFL’s, I suspected they were OK for 500KHz and I had tested the Inductance with 1 turn, it is huge. I used one of those cores and the sensitivity is much greater and hence load on the source less.

Well, Computer Modelling done, and some dry weather and no frozen feet this morning, I took my newly calibrated current meter to the garden and measured my Antenna Current as 73mA.

Results:-
No Loss Conductor Model (Not correct as Ohmic loss is important on 500KHz) – 260uW ERP – Gain 3.09dBi

Copper Wire construction (Correct for my Antenna but fed at ground level) – 370uW ERP – Gain 3dBi

Copper Wire construction and 300mm off ground Feed Point (Real Antenna) – 269uW ERP – Gain 1.48dBi

These figures take into account the accepted 3dB absorption, MMNA modelling will not factor absorption loss at 500KHz. For me anyway.

They tie in with M0BMU‘s estimates using received signal strength too.

Perhaps I should use 270uW as my stated ERP, I don’t know though, that’s only 1 dB.:-/

Now a picture of the Computer Model.

The important Current ‘sticks’ to the Vertical, the Top Load Current, Horizontal, is shown blue,we don’t much amplitude change here either, the concentration of current in the Hat turns it a nice overall blue.

Czech Republic on 500kHz QRPp confirmation

Lubos OK2BVG has uploaded the data from the G3XBM and G3ZJO 1000km busting night.

2010-01-20 22:16 G3ZJO 0.503819 -29 0 IO92ng +17 0.050 OK2BVG JN88ks 1310 814

Two more new stations also, one from Germany overnight.

2010-01-25 01:28 G3ZJO 0.503829 -28 1 IO92ng +17 0.050 DK8ZJ JO54ag 758 471

Also G0API at 185km.

2010-01-25 19:22 G3ZJO 0.503813 -29 0 IO92ng +17 0.050 G0API IO80xs 185 115

More problems with the WSPR.net data, both stations appeared on the Database so did their lines on the Map but they are phantom lines again with Mr Noboddy at the end. I hope its not just me.

That will be G0API then.

And at about the same distance as DL-SWL that will be DK8ZJ. Good job I copied it from the WSPR.net map when I did, no more than 20 mins later it has gone, yet DL-SWL is there and I asked for 24 hours of Spots.

Thank goodness the Computer Data System that looks after my Bank Account doesn’t lose stuff like it.

Current score on 500kHz 29 unique stations in 7 Countries.

500kHz QRP – QRSS sessions

A change of mode on 500kHz brought in some reports.

The Transmitter is the 4MHz Crystal divided by 8, modulated by a 16F628 PIC keyer. The PA is another Complementary Pair Class D, the transistors again ex Computer memory BFY50 and a CV No. PNP Silicon. I have replace the Inverter PA with this design, as used in my WSPR MEPT. Inverters being CMOS are limited to a 5Volt or so supply, I find them fine for HF where tens of milliwatts is used. On 500KHz you have to start to push them, the added current produces heat in the Voltage regulator but not much in the chip. This is totally wasteful, if I am going to burn my hands I want to do it on the RF device no the PSU.

I have built this TX with the Altoids tin in mind, each unit is on a board cut to fit the noble QRP enclosure. I had the Dispensers at the local chemists smiling the other day when I bought more mints and told them I only wanted the tin really, “they have a worldwide following you know”. “Yes sir, fine, keep taking the pills won’t you”.

It would be impossible to put the whole thing in 1 tin, so we have 3 modules, Keyer – RF Generator – PA. Ah! Happiness is a warm Altoids Tin.

The PA does not quite run as much power as the WSPR one, maybe it is the drive waveform, I have not worried about it as 500mW RF into 50 Ohms is just right.

The first session brought a nice report from G3XBM, interesting as we still have not managed to get a WSPR signal to him. There must be an answer to that somewhere.

Next G3CWB in IO91rm, BTW its downside up, read the bottom line.

Super signals at M0BMU, he is my standard by which I judge my performance, the first, and only for a while, station to receive my QRppppp when I first started with a dubious antenna.

G4GWT is at a fair distance in IO83qo 188.9 km or 117.4 mls. Captured at 1245utc on 24th January.

There may be more reports to come today, if so I will add them later.
A report was received from Mark GM-SWL, he sent some grabs which are pretty surely my signal although not enough information was clear for a positive report. Also after dusk Rik ON7YD copied my call several times.

Thanks to all reporters, unlike WSPR, you had a choice and put in some effort to spot the signals from IO92.

New Calls and Distance Record on 500kHz

Last night produced another Phantom Line on the QRSS.org Map. This time a line terminating in nothing goes up near Telford. However there is a new Spot on the Database which must be associated with it. Therefore I have done the labelling work manually.

Computers and their foibles don’t we love them aye?

 

I have also added to the map the Spot sent by e-mail by Lubos OK2BVG, I must ask him to add this to the database. I think that due to the RX being at his Portable location and he at home, Spots were not automatically uploaded.

Conditions on the 20th were superb G3XBM and I were keen to exceed 100Km on the band, Lubos OK2BVG went to the trouble of driving to his country QTH with a nice quiet background and installed his RX and Computer so that he could monitor from home. Now that is real Han Spirit.

I am not into claiming records / firsts for anything, this must be a good one though for the QRP involved and the distance.

It is 1310Km, according to the Loc.Distance software and equates to 6,550,000 Km per Watt of ERP.
In old money that is, 814 Miles, 4,070,000 Miles per Watt of ERP.

Estimated ERP is a difficult subject, I am prepared to accept that the actual power could be up to 10 dB more than stated. Well that is still peanuts and I am the lowest power on the band.

QRP don’t we just love it aye ?

WSPR2 Predictive De-coding ?

Now here is a funny one. Last night I was chatting to some fellow Hams on Twitter, I noticed a Spot on WSPR from F5WK. “A new Country for me on 500KHz I announced, France”.

After the congratulations I looked at the WSPR.net map.

 

The funny thing is on several occasions over several days I have noted a line from my QTH to south of Paris on the map, it terminated there and showed no call sign. Is this an example of some very spooky predictions by WSPR2?

I checked my Spreadsheet compiled from a Search on the Old Database for 2190-600m and my Call. Yes France was a new Country.
I then searched the Old Database adding the Unique Reporters filter and was startled to find 2 other French stations F0VDZ Spotted me on the 15th of January and was in fact my first France station. All three stations are in JN18 so any one of them could have produced the Spooky Line.

I am impressed and indebted for the sterling work done in producing the Database and facilities, however it is open to, False Calls generated by WSPR, Bogus data from Ham’s human error, Malicious data from Fools and Pirates and Database errors. I therefore smile when I read of highly technical analysis being made using bulk unconfirmed data.

I am not complaining, just noting what I find. Furthermore the following was composed using Microsoft Excel which heaven knows can do some stupid things. I would like to point out that I am not responsible. Oh sorry, …. for any errors contained herein.

Date Time QRG Report Power Rptr.Call Rptr.Loc Dist.Km
2009-11-22 00:48 0.503814 -30 0.000013 M0BMU IO91vr 76 England First Report no longer on Database
2010-01-05 20:40 0.503812 -26  0.000013 G7NKS  IO92ub 46
2010-01-10 06:14 0.503855 -21 0.00013 G0DEZ   IO92ub   46
2010-01-14 19:10 0.503824 -28 0.00013 OR7T  JO20ix 411 Belgium
2010-01-14 19:26 0.503832 -27   0.00013 M0LMH IO93gx 194
2010-01-14 19:36 0.503818 -25   0.00013 PA0A JO33de 493 Netherlands
2010-01-14 19:36 0.503819 -31   0.00013 GM4SLV IP90gg  890  Scotland
2010-01-14 21:28 0.503818 -27    0.00013  PA0AM   JO11sh 322
2010-01-16 01:34 0.503831 -24    0.00013  G0KTN  IO81ti 145
2010-01-16 11:04 0.503823 -26   0.00013  M0GNM   IO91wi 114
2010-01-14 21:18 0.503824 -25  0.00013 DL-SWL JO52hp 779  Germany
2010-01-14 21:18 3.594025 -24 0.00013 ON6EO JO11  277  Shows as wrong band
2010-01-16 19:00 0.503819 -29   0.00013 PE5T  JO33bi 485
2010-01-17 06:02 0.503836 -25   0.00013 G4KPX  JO02cj 75
2009-12-15 15:28 0.503856 -25   0.000013 G3KZU IO91js 60 Not called by Database in search
2009-11-28 12:56 0.503846 -26  0.000013 G3XVL JO02nb 138 Not called by Database in search
2009-12-29 12:40 0.503845 -25  0.000013 M0WQR  IO92vt 75 Not called by Database in search
2010-01-18 20:16 0.503831 -25  0.00013 G0HNW IO93cn 156
2010-01-18 21:52  0.503829 -23 0.00013  GM4PMK IO66xj 568
2010-01-15 23:26  0.503832 -26 0.000013 F0DVZ JN18fo 471  France Not called by original Database in search
2010-01-17 01:22 0.503820 -29 0.0002 F4DTL JN18fp 467 Not called by original Database in search
2010-01-19 23:40 0.503835 -28  0.0002 F5WK JN18hp 473
2010-01-20 04:30   0.503841 -25 0.0002 TWENTE/SDRJO32kf 527 

The present state of play:-

23 Unique stations.
5 Countries
890Km greatest distance.
200uW maximum Estimated Effective Radiated Power.

In Particular I like the report from the Twente University SDR which merely uses an 80m wire Antenna. Not my best DX on the band but that is 2,635000 Km, 1,635000 Miles per Watt of ERP.

 

The thaw allows Antenna work.

I sure chose the worst time for antenna work on 500KHz. My Inverted L was erected and modified in gales, the coil experiments were done in rain, snow and ice. It did give me a good test re the Haw Frost (the subject of discussion on a couple of groups) which formed on my Tuning Coil and de-tuned it, that now has an outer cover for the frost to form on.

My original IC PA lead me astray, by delivering its power more efficiently into an off tune antenna. I have been waiting for the chance to do some outdoor soldering as the new PA designs perform more logically and required just a little more L or C.

I decided upon adding C as I had some ‘Twigs’ 14g copper wire ready for experiments. Yesterday the WX was kind and the Twigs were added.

 

Upward looking antenna pictures are always difficult to interpret. The line from top to bottom is the Horizontal section of the Antenna and the support line from an insulator. The slightly kinky wire is the Vertical section which is not under such tension.
We are looking straight up under the Top Hat which has already been named by the neighbours as the ‘Flying Saucer’. As a size guide it is a Terry’s Chocolate Orange tin lid 240mm in dia. Yesterday it got a coat of Hammerite paint for protection, being thin, but of course light weight, it would soon rust through. Now it is no longer recognisable a sweetie tin lid by the uninitiated.

I have not seen a solid disc Capacity Hat arrangement used on 500KHz. Wires are used in many top loads yet we need Capacitance and that is related to plate area, I have no room for large wire arrangements so mine is lumped. For clarity I have produced a sketch.

 

Just like a ‘Hairspray’ antenna we have a short inductively loaded antenna resonated by a capacity hat and a final wire. The Resonance can be adjusted by varying L, the Loading Coil or any part of C the Top Hat and Top Wire.
It would be possible to remove any adjustment of L and to resonate the system by pruning the Twigs.

This work may well have increased my ERP by 1 or 2dB, I will now consider my ERP as approaching 200uW. This may be not too ambitious as it would point to my antenna approaching an efficiency 1/10 of that of G4JNT.

Station and Country count on 600m

Oh dear, WSPR Database blues, I have started my own Spreadsheet to save new data as it comes so I have it before the Data Worms start eating away.
It is job enough to keep track of my Spots on 500KHz without reports failing to appear in a search. I found myself doubting my own sanity, “I could swear I had a spot from a guy in Lincolnshire” yet I went cross eyed trying to find it on the Old or New Database.

Thank goodness for this blog, here I looked back, found the call sign asked the Database for that particular call and it comes up, several entries for my Spots. Yet in a full listing they are excluded. There are 4 unique Call Sign entries like this, only 4? Out of a total of 16 uniques that’s frightful 25% error what use is a Database like that.

The oldest entry my first Spot on 600m on 22Nov 2009 has gone from the Database completely, again its on this blog so I am sane, as usual computers and systems are mad.
One station ON6OE was another worry, I finally found it, his dial freq was in error and his report sat in the 80m list.

Here are the figures:-
16 different Stations Reporting
4 different Countries
890 Km Greatest Distance
130 uW Greatest ERP used.