The International Association of Luddites + More 500KHz

I often just cannot believe some things in this fine technical hobby of ours. The number of Luddites is amazing. Several groups have a loud, rude contingency who voice their hate of WSPR and all things Digital or involving a Computer. Most likely they sit at an immaculately tidy desk with one commercial radio on it with the power turned down (so they can say that they run QRP) and a Morse key.
Now one group has bowed to the Luddites and for all intents and purposes banned the mention of Computer related posts. I know there are other ways of looking at this, but this is my personal opinion on my blog. Heaven knows you dare not express an opinion within the groups, that is all they are there for it seems, snarling at each other and ridiculing someone who is new and having a go. The fellow I have in mind here has been remarkably polite and tolerant of his ignorant taunter, proving himself far and above a better person. Ha! I feel I may not have managed such politeness.

Can someone please start a group for the Narrow Minded and send them all there.:yawn:

What can you do with WSPR on 500KHz that you can’t do on the key was one subject. “Well get a proper report in 2 minutes having made Antenna changes, how many CQ calls on the key would it take before I got a reply to my signal that as yet has never been reported as being heard?” How meaningful would that report be, I listen to a few Morse QSO’s on 500K and yep the reports both ways are normally 599.

Likewise who is going to sit throughout the night giving me reports on my signal, even if I was prepared to send a CQ or TEST every 10 minutes.

I added the disc Capacity Hat to my 500KHz Antenna to see what it would do in practice. In theory it concentrates the Current higher in the Vertical section and is the aim for most stations on 500K. I am sure it has done as expected, however the current high then is closer to my Mast and VHF antennas which are far taller and well earthed. Absorption therefore could cause attenuation of the signal. My reliable daytime path to M0BMU vanished to be replaced by M0WQR.
Another new reporting station and No.6 for me.
With so few stations on 500K WSPR it is surprising that I have yet another 2 stations who are equidistant, within 1 Km which makes things interesting.

So why the difference in received signal? I suspect that as M0BMU is a TX station on 500KHz, his Antenna will be mainly Vertically polarised. M0WQR however is an RX station, maybe he has more Horizontal response from a more universal Antenna, my inv.L has some horizontal component for sure.
The darkness path to M0BMU was fine on 29-12-2009, I awaited the ‘switch over’ last night. Unfortunately M0WQR literally switched off around 21.00 but as can be seen, the path to him faded around the onset of darkness. M0BMU came up around 22.00 then was solid from 02.00.

2009-12-30 02:32 G3ZJO 0.503833 -26 0 IO92ng +17 0.050 M0BMU IO91vr 76 47
2009-12-30 02:22 G3ZJO 0.503830 -26 0 IO92ng +17 0.050 M0BMU IO91vr 76 47
2009-12-30 02:02 G3ZJO 0.503831 -29 0 IO92ng +17 0.050 M0BMU IO91vr 76 47
2009-12-29 22:02 G3ZJO 0.503830 -31 0 IO92ng +17 0.050 M0BMU IO91vr 76 47
2009-12-29 17:30 G3ZJO 0.503838 -28 0 IO92ng +17 0.050 M0WQR IO92vt 75 47
2009-12-29 17:20 G3ZJO 0.503838 -27 1 IO92ng +17 0.050 M0WQR IO92vt 75 47
2009-12-29 17:10 G3ZJO 0.503835 -27 0 IO92ng +17 0.050 M0WQR IO92vt 75 47
2009-12-29 17:00 G3ZJO 0.503836 -29 1 IO92ng +17 0.050 M0WQR IO92vt 75 47

Varying conditions of course play a part so I shall leave this Antenna set up for a while.

Next Day
Variable conditions it seems to have been, how typical after an Antenna change. M0WQR has not been RX’ing again, I don’t know how is one supposed to do tests :DD. M0BMU is back day and night with maybe an improved report.

I had no intention of trying to join the big guns on 500KHz, it seems there is no chance anyway. Any move I were to make to my Antenna would merely serve to bring the Vertical section nearer to yet another absorber. I have the 6m Mast that supports the far end of my 6m high 500KHz Inverted L, not to mention the aluminium greenhouse in front of it. A 6m Vertical Antenna to the right. My 40m Doublet 6m high to the left and the VHF mast with beams behind. Off the ground wall mounted Top Loaded Verticals are out,(no room). It is a case of how much of my tiny power level can I get out of a Faraday Cage.

The Return of the Sweetie Tin Lid to 500KHz

I think I now have reached optimum with my 500KHz Loading Coil. Next I have turned my attention to Capacitance in the Top Loading. What I have not seen in any 500KHz Top Hats is a solid version. As Capacitance value is related to plate area, a small solid disc must be equivalent to quite a lot of wire. Whether this will provide an advantage at 500KHz remains to be seen.
I am sure I saw at least a 3dB increase on my locally received signal when I tried just the disc. I then added some circles of copper wire and after the necessary Loading Coil modification due to the added Capacitance I could not achieve the same indication. However it was dark, cold and misty by this time making critical adjustment difficult.

It did provide an irresistible photo opportunity.

The disc is at the top of the 6m Vertical section, of the Inverted L antenna.I am not sure quite how it will behave in the wind, time will tell.

Next Morning
I measured the Antenna Capacitance looks like about 20pF from the tin lid, if its 20pF and 3dB gain that’s not bad from a Terry’s Crispy Chocolate Orange Segments lid. Emptying the tin is no great hardship either.
If it stays it will get a spray with white paint, it seems to be fairly stable in wind, rain and snow, yes we have had them all since hoisting it up.

EDIT. Later heavy snow which froze, melted and produced huge icicles then more heavy snow settling caused excess sag an twisting of the disc, it has subsequently been removed.

A Quart out of a Paint Pot 500KHz Loading Coil

I have displayed and detailed various 500KHz Antenna Loading Coils here that I have experimented with, not all though, it has been fun experimenting.
What I can report is that thin wire coils can be surprisingly efficient if the windings are close spaced and high Q by the introduction of Ferrite. Thin wire spaced coils of course have more DC Resistance and this shows up as a loss.
My Trifila coil reduced the resistance and showed promise but ultimately there was an efficiency problem, was it my imperfect hand twisting?

My first coils were link coupled, my 100mm dia. Helical Coil on a Racal former is a good performer and hard to beat. Long tapped coils need to have taps provided sometimes a long way up the coil, a nuisance if you decide you want to try just one more turn up or down.

In my Loft I had some left over PTFE insulated, Silver Plated wire, 2mm overall dia, I used it for my 40m Doublet, a rough measure out of the remainder indicated that it would just be sufficient for a large dia Loading Coil. A good advantage of a large coil is that the 50 ohm tapping point should lie somewhere between turn 1 and 2, this meant that I could use 2mm Enamelled Copper Wire for the first 2 turns and thus provide good solid tapping points at .0625 of a turn. Needing to be sure that I am scraping every possible dB out of my coil I wound what may be my final coil on a Paint Pot 210mm dia.

The DC resistance is very low, from RF field measurements, as accurate as I can make, the efficiency is better than the Racal set up. Final adjustment is with the same Ferrite Push Rod arrangement as used on all coils. The coil is wound with 1.5mm Enamelled Copper Wire just 22uH without the Ferrite. All coils are interchangeable and thread together, useful for tests and adjustments.

On air tests continue with this coil. I intend to add a weather proof cover to keep water out of the turns as soon as I can use up the paint from a larger pot which will do the job nicely.

WSPR2 on Ubuntu 9.10

Having stopped winding coils for Antenna Loading on 500KHz for five minutes I spent a little more time with Ubuntu 9.10 and WSPR2.
I decided to start with a clean install of Ubuntu, I suspect that some who have WSPR2 running on 9.04 and 9.10 have already got a Linux install with some of the dependencies already installed. From what I read on the web it is a tale of woe for many.
Some have said, ‘run Linux and execute WSPR for Windows under Wine’. Sorry for me that is a farce.

So I ran WSPR2 on my clean Ubuntu 9.10. The first step crashed out with error messages requiring libraries, at least the error message listed what was required. I added what was asked for and it ran with the error message from before.

There was no sound input. I configured the sound card. None of the sound input selections provided an input and WSPR2 crashed out each time at decode.
I resorted to my list of dependencies in my WSPR.net blog.
Unfortunately I don’t know at what stage it started working, was it libsamplerate that did it? Be assured, as per normal if you have 2 sound cards installed, Ubuntu will swap them round at some time and get you confused, also WSPR2 will forget it ever knew you had 2 sound cards and throw them completely off the list.

Well somewhere in that mess it started working. It still displays 4 rows of error message as above whilst working.

This time the Green RECEIVE box didn’t flicker like the program was about to collapse, but the sound levels are very low, not usual on this machine on Windows or Linux, and oh those labels. WSPR2 User Guide covers this :-

I’m running WSPR under Linux, and the labels above decoded text are poorly aligned.
1. Details of screen appearance depend on configuration of your window manager, installed fonts, etc. You can experiment with fonts by editing the file wsprrc. As an alternative, try making a backup of wsprrc and then copying the supplied file wsprrc.alt to wsprrc. An example of the resulting screen appearance at OZ1PIF when running Ubuntu 9.04 is shown on the next page. 19

Now then I happen to know that Peter OZ1PIF has a huge monitor, just look at the aspect ratio, I produced compiled versions of WSPR to fit his monitor in the past before I modified the fixing of the labels so that the compile was transportable between different set ups. Note that the picture shows a relatively huge left shift of the label row.
I did try editing the fonts as described but the major problem does not lay in the size of font but in the initial position of the start of the label row at UTC. Changing font size will not move that. Unless of course you know better. Personally I consider it the programmers job to place labels correctly not the user, you don’t need to do it with Windows.

USA ON 500KHz again

Last night I copied WD2XSH/17 on 500KHz again, this time a positive identification and several other stations for comparison.

2009-12-23 23:58 WD2XSH/17 0.503890 -23 0 FN42pb 10 M0WKR IO94eb 5085 50
2009-12-23 23:58 WD2XSH/17 0.503901 -26-1 FN42pb 10 G3ZJO IO92ng 5187 52
2009-12-23 23:58 WD2XSH/17 0.503926 -24 1 FN42pb 10 DK6NI JN59ln 6068 52
2009-12-23 23:58 WD2XSH/17 0.503901 -21 1 FN42pb 10 G0NBD IO83lk 5012 51
2009-12-23 23:58 WD2XSH/17 0.503891 -24 1 FN42pb 10 F4DTL JN18fp 5542 56

I am still testing Loading coils for 500kHz, hopefully soon I will have a best performer which I shall use permanently.

500KHz signal comparison

The reports from G7NKS the mid way station between G3XBM and G3ZJO tonight are showing only the 15dB Power difference between XBM 5.0Watts and ZJO 0.160Watts.

Ignore the WSPR indicated Power levels.

2009-12-16 22:28 G3ZJO 0.503806 -25 0 IO92ng 0.05 G7NKS IO92ub 46 120
2009-12-16 22:28 G3XBM 0.503885 -10 1 JO02dg 0.001 G7NKS IO92ub 46 240

I am working on a quick change system for my 2 Loading Coils for comparison purposes, I still alternate between my link coupled Racal Glass Fibre former coil and the Trifila tap coupled one.
If only it would stop raining tests would be much easier.

500KHz across the Pond

What an intersting ( spelling intentional, it often turns out that way with my typing and is hard to spot, it is now one of my edipropisms) band 500KHz is.

Yesterday I modified my antenna, its now an inverted L, it tuned fine, I had regular Spots from 4 stations in the afternoon, the most stations ever at one time. At 19.44 GMT Spots ceased, sometimes this happens as the Ground Wave signal attenuates after dark, stations tend to return later and are normally solid by 01.00 GMT. The operation pattern of RX’ing stations can cause total black out too of course 🙂 I had no Spots throughout the night this is most unusual.

Maybe I was a little off tune with my Loading Coil G7KTN Spotted me this morning after I re-tuned.

However, here is the intersting bit, I tried my Antenna on receive, SM6BHZ was very strong, audible, the band was very quiet, computer QRM is much less without the Top Load arm which headed toward the house.
I received a Spot with a # call.

091215 2252 5 -30 -0.3 0.503902 # FN42PB 30 0 2 0

Just another duff Spot? No, I recognised the QRA WD2XSH has a beacon in that square, to send the /17 he will be forcing WSPR2 to send a 6 digit locator hence the #.
Only two other UK stations copied anything from across the Pond in the USA as far as I can tell last night.

2009-12-16 07:14 WD2XSH/17 0.503889 -23 0 FN42pb +30 1.000 M0LMH IO93gx 5098 3168
2009-12-15 22:32 WD2XSH/17 0.503891 -25 0 FN42pb +30 1.000 G0HNW IO93cn 5089 3162

My Antenna without much Top Loading is not so efficient as a Vertical, with some Horizontal polarisation it is doing a good job on the DX.

STOP PRESS

The Antenna was miss tuned,in the failing light slight falling snow and miserable cold I didn’t spot that I was actually going through a peak at maximum Inductance available which was not quite enough, near enough for RX’ing of course.