15m looking up!

Even with a modest hexbeam on his side, and a very modest vertical stick on the car on my side, VK4BOB was coming in very nicely at the coast this morning - too much of a pile-up, which I will rarely try to get involved with - for a QSO.

D60 what?

Having recently moved house, I find myself increasingly putting things where I then can't find them, and going off to places, having forgotten to bring something with me.  Or maybe it's just getting older!

Yesterday afternoon was gloriously sunny and a perfect balance between warm and cool.  I decided to set off for a local lake and play on 15m, which was wide open to most of the world.  

15m operation often causes my Raspberry Pi computer - if I'm using it - to crash.  This is because the short coax length - to minimise cable losses when QRP - is similar to a 1/4 wave radial on that band.  In addition, the short coax means I'm quite close to the antenna, where the field strength, even at 6W PEP, is quite high.  I was prepared for the problem this time, having previously wound a small ferrite to make a simple 1:1 choke balun, which I connected near the feedpoint.  Matching remained perfect at 1:1.

As is often the case in ham radio, things made in a hurry for a specific need become useful in the long-term!  A simple 1:1 choke balun for the vertical.

Of course, I forgot the USB battery pack!  I turned back, changed my mind, and went off to check how my shack-in-the-field was doing after a long period of not having visited.  It's an interesting site for radio, because it's very marshy, where the water table varies between about 1m below the surface in a dry summer, to forming a small pond and thus breaking the surface in winter.  An old well conveniently allows inspection of the water level!

Nice day for /P!

 

Having trundled across the fields to get there, I set up my 15m, 1/4 wave vertical and tried some SSB for a change.  Now that propagation is improving quite dramatically, people seem to be returning to actually talking to one another.  From a portable operations perspective, SSB is less of a burden in terms of not needing to carry and fire-up a computer, with its associated power source and accessories.

Anyhow, sitting there in the sun, I heard a fairly weak but very stable signal from D60AC.  Hmm.  I had no idea where that was.  Well, I gave him a call on all of 6W PEP, and he heard me first time.  Then I looked up where he was - the Comoros islands - at 8570km!  

Wow!  How many would laugh at the suggestion that was possible, especially without any long path/grey line enhancement?

 

New CE3JSX WSPR beacon

I was delighted to be sent some photos by Maury, CE3JSX last week, showing the installation of a new WSPR beacon.

Image (C) CE3JSX

 

Covering 80, 40, 20, 15 and 10m, the beacon is located in a good environment near Rancagua, just south of the capital, Santiago.  I've previously received signals from the earlier beacon on 14MHz when most others have vanished under unusual conditions.

Image (C) CE3JSX

Not bad...

This morning's to-ings and fro-ings on 12m.  Not bad for a shallow sloping delta loop in a not-very-good location!

Sea King HF Antenna

I came across some photos from, it seems remarkable to me now, 11 years ago, when a Sea King rescue helicopter came in for a few tonnes of Jet A1 fuel at a nearby private airfield.

 

I'm quite curious about the HF antenna that is located on the port side of the aircraft.  Superficially, it seems a simple dipole.  But a closer examination reveals several wires or ropes attached to the main radiating elements.  I'm not sure if some of these are to stabilise the wire in the downdraught from the rotors.  Or maybe they are some complex feed mechanism?

Similar, probably earlier Sea King antenna plan.

Since 2010, the RAF-operated Sea Kings have been replaced by a private search and rescue service.

My son in front of one of the local privately-operated search and rescue Sikorsky S-92 choppers.  The main rotor assembly feels like alien technology, so complex is it.

10m Activity

A fair bit of activity on 28MHz today, including fairly good receptions of YB (-17dB) and very good reception of VP8LP (-6db SNR).  Signals resurgent this evening, notably towards Norway.

Big outbreak of 'autumn' mesospheric summer echoes

A bit more geomagnetic activity has led to an outbreak of quite strong and extensive, almost summer-like mesospheric echoes today.  This was apparent on 12m and I could even see some WSPR signals on 10m this morning.

Up early - to no avail!

Equinox is not only a good time for long path radio, but is also convenient, as you don't have to get up too early!

WSPR from the previous day narrowed down the peak long path signal time between 06:50 and 07:10UT.  

Around sunrise, facing the long path to the south west.

 

I was out and ready to communicate by 06:30UT.

Sadly, there was a hell of a lot of noise on the 20m band - for reasons I can't fathom.  Even FT8 was a struggle.  The same was reported in Australia by Peter Parker, VK3YE, who kindly responded to a call for a sked online the previous day - and who consequently couldn't hope for a QSO.

But there was an interesting simultaenous long and short path reception - almost impossible to say where the station was, but there are good hints of a ZL or VK accent at times. 

If you listen with good headphones, you can hear the echo and, from time time, very rapid, brief changes in signal strength, which seem to be primarily down to phase differences, probably interactions from the many paths taken under antipodean focusing.  The focusing happens when radio waves go off in all directions - such as they do from an omnidirectional vertical as I use -  and end up meeting again under spherical geometry at the antipodean point.  A directional antenna is actually detrimental to this propagation mechanism, often very significantly so.

I did manage to listen to VK3QN on WSPR at 07:20 and 07:30UT.  The difference in latitude, even when small, is critically important as to signal strength received at long path time.  Even so, I was hearing Ian 26dB stronger than the UK median SNR at 07:20UT, and 20dB stronger at 07:30UT.  Being by the sea is worthwhile!

Thoughts turn to summer.

One band I haven't tried from the beach is 6m.  But with such great success on other bands, I think that come next summer, I should have a go.

One nice thing that's possible on 6m, where it isn't really on other, upper HF bands, is using a Yagi in a vertical configuration.  This should provide really quite spectacular outcomes for DX paths from the coast, such as that to Japan.  Due to convention and the lack of suitably-located operators, such vertical beams seem to be extremely rare.  

I'm going to try some 6m Far East DX next summer...

 

Let's see how this works out at 10m, which is a stock, 6-ele model provided in MMANA-GAL, simply for convenience; the general outcome will be much the same at 6m.  First, the horizontal pattern, using an 8m mounting height, which is about the maximum we might reasonably achieve on a portable outing.  Ground type is 'perfect', which is not too far from what we get with seawater:

 

 

 

 

And now, turning the beam on its side so that it's vertically polarised:

The difference between them is enormous at very low angles; we get 17dBi right down to the horizon, whereas the horizontal beam has a big gap starting below 15 degrees, falling away to very poor radiation at much lower angles. 

To put this into context, a 5W input would come out as 250W.  10W as 500W, and so on.

Colleagues such as PE4BAS have a good track record of making JA QSOs with horizontal beams each summer.  I never really put in enough effort, nor had a particularly good aspect towards JA from my last QTH.  I hope to change that now.

Hopefully, I'll have a drive-on plate and modest mast and side arm to mount a vertical 6m Yagi done-up over the coming winter.  Or maybe I'll try a rear-mount quad array, as supplied by Innovantennas?  We'll see...

'Es' appears after magnetic event.

Quite a significant disturbance in the geomagnetic field before midnight corresponded to the appearance, a few hour later, of extensive PMSE at high northern latitudes today.  PMSE have been absent for several weeks, as is usual due to seasonal effects.  I wonder if it will cause higher HF Es?

New stick!

 

Early autumn light and clouds today!

I added another stick antenna to my collection this morning - this time, for the 15m band, which has livened up considerably recently.  

This stick came from Sigma-4-antennas on E-bay, saving me about £5 in the delivery charge others were asking.  It was here next day, and matches up at 1:1. 

Perfect match!

An hour down the beach with 15W out proved very worthwhile:

The logbook continues to look better than it ever did from home!  Quite amusing to end the run of red and white flags of Indonesia with the white and red of Poland!

At the tide's edge.

A quick visit down to the beach again this afternoon, see what was cooking on 17 and 20m.

View from 'the shack' at high tide.

 

After a few FT8 QSOs on both bands, I turned very briefly (13:30-13:52UT) to some 1W WSPR at 14MHz.  The results were very pleasing.

 

22 minutes' worth of WSPR effort at 14MHz.

For example, here's KL7L receiving everyone at the time.  Not so many from Britain getting across to him.  Compared to my signal, G7WAW/P was only 1dB weaker, on a Watt-for-Watt basis - a very good performance, though I don't know what antenna was in use yet.  

G0IDE was 12dB weaker on a Watt-adjusted basis.

Meanwhile, VK7FLYN was receiving me 10-11dB stronger than G0CCL, and 13dB stronger, on an output-normalised basis, than both G0IDE AND M1DRK, the only other UK stations getting across to him at this time.
 

A collapsing signal at 7MHz

Very nice, dramatic collapse in the signal from GM4JSB last night, as a strong pulse of geomagnetic disturbancebrought a rapid northwards, then southwards dip in the field:

Collapse in GM4JSB's 5W, 7MHz signal.

EA8BFK, meanwhile, heard my 1W signal peak as the field reached maximum northerly deviation, with a corresponding collapse and, for around three hours, a vanishing of the signal, as the field went southerly:

Recently, on 17m...

Very pleased with how my 15W FT8 QSOs with a £22 Ampro whip antenna have been going from the beach recently:

Another fab hour at the beach

An hour on 15W FT8 and a stick at the beach on 17m again this morning.  I've made more JA, R0 and BA QSOs this week than in several months, on any band, previously.  Abandoning the old, QTH-based operation is really a good thing for me.  Cheaper, too!

Evaluating a low sloping loop (updated)

Earlier this week, I put up a random-length, shallow-sloping delta loop at the new QTH.  Although noise levels are surprisingly low, I still plan to do almost all of my working from the car on the coast now; the coast is simply infinitely more effective than home operations.

Being quite low, the loop was never going to be 'world-beating' like my previous location allowed antennas to be.  Then again, it's nowhere near as windy at the new QTH, and the loop will survive with ease, with no need for retraction.  Life is a compromise, with antennas.

Even so, the loop gets out surprisingly well at 30m, as this comparison against a doublet (10m legs) in inverted-V configuration, apex at 8m, shows:

Receptions of my loop's output (green) and my own receptions of others (red).  Sorry if you are colour vision deficient; it's not my choice of colours!

UPDATE:  Although better propagation is certainly helping matters, I'm rather pleased with how this antenna is doing.  The QTH has a reasonably good, low takeoff to the NE-SW half of the sky, not so good to the West.  Plot is of 10, 12, 15, and 20m activity for a couple of hours this afternoon at ~15W FT8: