Saturday 29 July 2017

FT-8 Logging: why the angst?

There's been a lot of excitement about FT-8 of late, but also a lot of angst about how best to log the mode when LoTW is not yet accepting it due to ADIF not yet updating for the new arrival (a look on ADIF reveals an update is imminent at the start of August).

Just auto-log it!


There are two broad camps that have formed:

(1) Those who are going to avoid using FT-8 until LoTW is sorted out.  I've tended to fall into this group - until today.

(2) Those who are going through protracted processes to 'map' FT-8 to 'Data' (unlikely to be confirmed in the same way by the other station, and thus rather futile).

The second camp seem to be a group of people looking for a problem.  All they need do is use the logging feature of WSJT-X and keep the ADIF file thus generated until LoTW accepts the mode, where it can be uploaded with, one hopes, no problem.


Wednesday 26 July 2017

12 Metres Sporadic E.

We're all familiar with sporadic E on VHF frequencies.  But how about 12m?  One never comes across any excitement about the 12m Es season opening or, indeed, any discussion about 12m Es at all.

Yet, it is pretty obvious to any regular user of 12m that the band is highly subject to Es propagation.

This morning, for example, 12m is again alive (during solar minimum) with short-skip signals from across the EU at very high, saturating signal strengths on JT65A.  The signals also show rapid changes in strength with time, indicative of gravity wave structures in the atmosphere.

Strong and rapidly fluctuating signals from central EU this morning.


To back up this idea, one only needs to look at one of the many MST radars placing their data online.  This morning, correlating well with the position of Es clouds as revealed by amateur radio signals, the 46.5MHz radar at Aberystwyth, mid-west Wales, shows strong returns from PMSE (ionised) structures which, at the signal strength reported, have probably just about reached visible ice structures as well (leading to NLC displays at night).

Here comes the PMSE...

So there is no doubt that Es is present and common at 12m.

The following day, a beautiful example of moving-surface drift was seen from EA5MM, underscoring the nature of Es propagation:


Curiously, the following day, 12m signals started appearing from central Europe in very strong form from nowhere.  This coincided precisely (at 19:00UT) with the passing of a cold front over my QTH and, within about six minutes, the band went dead again. The two signals, a HB9 and DL6 station, lay on a path perpendicular to the front's position.  Whether this was mere coincidence or not isn't clear to me, but it seems worth investigating!


Tuesday 25 July 2017

10m DX Amazement!

If I look at my 2012 logbook, it's stuffed full of DX across the world on 10m. 

Today, at sunspot minimum, QSOs on 10m are largely confined to fairly rare and transient sporadic-E openings.

Last evening, I was quite amazed to get a weak copy using JT65A into central Argentina - LU4HOQ.  By weak, I mean weak - just -23dB on receive, and much the same the other direction. I was using a vertical delta loop operating on its first harmonic, and the LU station appears to have been using a vertical of some sort.

Still, it does again show that the weak signal digital modes are now redefining accepted wisdoms about band openings, in that QSOs on upper bands are sometimes possible where they were previously not, even on CW.

'Shut up and operate' once again proves its worth as an approach to amateur radio!

Thursday 20 July 2017

New FT-8 Mode - Digital on Drugs!

Do you remember SIM-31 mode?  Probably not, because it came and went without anyone taking much notice.  It's now hardly ever heard.

SIM-31 was a digital mode, similar to PSK-31, but entirely automated.  The human - that is, you - was rendered redundant in the process of making QSOs.  It seems that level of redundancy made the mode and, if extended further, the hobby, futile.

Over past days, I've noticed a new mode appear just below JT65 mode on 14MHz.  Using FLDIGI and other software, I couldn't work out at all what the mode was.  Several lines of transmission appearing and ending simultaneously every few seconds.  Very odd!

Eventually, I found out about FT-8 mode, which is a new Joe Taylor (inventor of a plethora weak signal digimodes) mode.

FT-8 underway.  Very fast, but a bit unrewarding.


After downloading a new candidate release WSJT-X version, I was off on FT-8 mode in a jiffy!

WOAH!  Get me off this runaway train!  Well, that's how I felt initially.  FT-8 is a world away from the very pedestrian pace of JT65 and JT9, which take about 50 seconds per 'over'.  FT-8 completes an over every 15 seconds, and you have zero time in between overs to choose a different response to the usual, or enter a jolly greeting to end the QSO.  This makes manual use of FT-8 very manic!

After a while, I realised that there is a check box that allows the software to look at the response just received from the distant station, and issue the appropriate next transmission.  The human is therefore not entirely redundant, reduced merely to selecting which station on the waterfall is desired, and letting it all proceed without further intervention.

I have to say that the feelings of SIM-31-like futility and non-reward came back quite strongly on using FT-8.  The sheer speed of it all means it is solely a mode for gathering QSOs as fast as possible.  In practical effect, it's a bit like a permanent contest, where nobody wants anything other than the QSO 'points'.

Do note, though, that at the moment, whilst e-QSL is already accepting FT-8 mode QSOs, LoTW and QRZ.com are not. The workaround seems to be to use e-QSL, and then upload an ADIF from that site into LoTW when they finally get around to accepting the mode.

 That said, JT65 and JT9 are hardly rag-chewing modes, so I guess there is a place for a digimode that allows QSOs to be completed efficiently, albeit with significantly less sensitivity (around 10dB less, compared to those former modes).

Using FT-8 for a while, it's clear there is a good spread of DX from around the world, not unlike other weak signal modes.  The signal reports are consistent with FT-8 being less sensitive.  The mode is certainly very popular at the moment, with signals spread out over a good width of the digimodes portion of the band.


Certainly an interesting development, and one that probably has a place, albeit not a relaxed one!  Its appearance has only reinforced my interest in CW, where I hope I can enjoy the benefits of a relatively weak signal mode and enjoy some real human interaction.  QSO points, like any activity in life are, ultimately, pointless.

Tuesday 18 July 2017

Amateur Microwave Bands - Elitism Extreme?

This month, there's an interesting article in RadCom about receiving signals from research spacecraft exploring the Solar System.

Whilst I make no comment at all about the authors and contributors of the specific article in question, the fact remains that the GHz bands are extraordinarily specialised - and many seem more than happy to keep it that way.

The odd construction article does appear from time to time in the GHz section of RadCom.  But I doubt more than a tiny handful have ever benefited from those.  The trouble is, GHz band use requires a lot of technical know-how, and even more technical homebrewing. 

That kind of knowledge and expertise would have been reasonably common a few years ago.  But not now.  One of the most technically-adept operators I know locally says that, even with his ability to homebrew specialist kit, there is then the infinite problem of having no-one else to 'talk' to. 

This is a very sad state of affairs.  All the societies desperately try to make out amateur radio has a relevant, real-world use in the modern day.  If this is so, then microwave operation surely should be at the very top of their agenda, given the utter dominance of those frequencies in modern communications systems - and the threat they ceaselssly pose to the amateur GHz bands.  Yet, it languishes at the bottom of the well, the preserve of the wealthy, time-rich Baby Boomers, few of whom seem to have any inclination to introduce newcomers to the 'upper' bands.

Because new 'record distances' regularly feature in the GHz section reports, and that the hobby is, in general, prone to too much machoistic 'contesting', one comes to suspect that a primary motivation for keeping the upper bands free of the wider ham community is to ensure a small elite corner the market in achievement. 

I've seen the exact-same thing in top-end astrophotography in the hobby of amateur astronomy.  Groups existed - and still exist - that actively deny membership to anyone who hasn't got a long publishing record in the best magazines - which inevitably means denying membership to those who don't have the cash to invest in £15,000 set-ups.  No room there, then, for those who can innovate and produce great results with 'lesser' systems.  Unlike ham radio, though, amateur imaging is always advancing, and commercial computerisation of equipment makes it increasingly difficult for elites to maintain their position.  You'd be hard-pressed to find any plug-'n'-play GHz equipment - and even fewer that don't need a loan to buy - within the normal ham radio press.

The saddest thing of all is that I'm sure those who truly understand the technicalities and have an inclination to help others, would be able to get newcomers going in the GHz bands quite quickly.  Sadly, those kinds of people seem to be rare and, due to their age, are becoming rarer.

One group that seems to try and help the newcomer is the UK Microwave Group.  I was quite enthusiastic about their GHz equipment loan scheme - until I read that one had to arrange collection of quite bulky equipment from Glasgow.  I suppose it's useful for those in the area, but a bit of a nightmare for those who are not.  Once again, I find myself seeing some light at the end of the tunnel, only to realise it's an oncoming train...

Monday 17 July 2017

Amateur Radio Products - WTF?

Let's make a couple of assumptions about you, dear reader.

You are a licensed amateur radio operator, who has undergone at least some basic training, and passed some form of examination.

You can use a pair of scissors, and do some basic soldering.

To that extent, I don't think I'm likely to be very far wrong.

Why is it, then, that in the latest pages of RadCom, as many other magazines, we skilled people are offered products that are both extraordinarily simple and fantastically expensive?

By this, I don't mean some kind of transceiver that needs some thought and a list of components.  I mean a simple wire antenna.  There's an end-fed wire in there - something you can make possessing almost no skill and some ice-cream pocket money - selling for £160!

Then we have yet another small ('magnetic') loop offering to add to the very many already hoping to make a killing from the dumb operator who thinks there's some magic in their making.  A piece of coax and a capacitor in a box (no, it's not even a remote tune version) - oh, and a tripod and 'field' bag - going for just under £300 (or just under £400, if you want the lower band coverage!)

From all-new materials, plus an E-bay capacitor, my latest loop cost maybe £50, with the very distinct advantage of a much more physically stable and efficient radiator in the form of wide-bore copper tube. True, it won't fold down into a bag, but it can be made car-portable.  For real 'wild operating', I'd always backpack a much more effective quarter wave wire rather than a magloop, any day.

Sure, there are always people who are simply too nervous, short of time, or plain dumb enough to buy things you can knock-up for pin money from scrap bits of wire.  But the hobby can come to suffer from offering far too many simple things for too much money.

For one, it generates the impression that there is some justification - other than simply profit-making - for those high prices.  Magnetic loops fall into this category, with talk of 'lethal voltages' and 'kilovolt breakdown values' for capacitors.  Yet, they are as easy to make and safe to operate as a dipole.  Someone, somewhere aided by the internet, has decided that only the superhuman can build an effective loop, and that you will die if you try to do it yourself.

The other side is that, through the endless and profitable search for advertising income, hobby magazines come to be full of advertisements for things we don't need to buy, and portray a hobby that is too expensive for today's already debt-ridden society.  Advertising rates are very high for those places where you're likely to take notice of them, meaning that the most expensive gee-whizzery gets all the prominence.

Of course, just about all magazines are advertising outlets, padded-out with the odd article (and not the other way around), simply because, without the adverts, those magazine wouldn't exist - despite their increasingly and alarmingly-high cover price; it's not uncommon now to find magazines costing £10 on the news stands.

Wouldn't it be nice, instead, to see magazines full of cheap component sellers, padded-out with 'DIY' articles, rather than purveyors of ready-made £160 end-fed wires and £5000-plus transceivers?  Well, we can hope...



Thursday 13 July 2017

Stealth Antenna for 20m

During the recent warm, summer evenings, I've been busy fixing very minor storm damage from last February up on the roof of our old cottage.

For this, I have to use a 4.5m roof ladder (with ~1m added length from the roof hitch), which I recently bought for about £100.

Looking at its shiny aluminium-ness up on the roof, I wondered if this might not qualify as yet another stealth antenna that anyone, no matter how space or HOA restricted, might be able to deploy as an effective HF vertical.  At about 5m long, it's suited to a test on at least 14MHz.

I have no need for a stealth antenna, but I do like to experiment and, if I can, prompt others to look at ways of overcoming today's intolerant neighbours.

Using the usual short piece of coax from an ATU to a 4:1 balun, and then a run of 300 Ohm twin to the ladder, I simply clipped one side to the base of the ladder, and attached a single counterpoise loosely over the ground. 



Now, I don't know about you, but I think you would have to have completely insane neighbours, and an even more insane local authority, if they tried to claim this was something that broke planning rules.  I doubt anyone would in fact ever realise it was being used as an antenna.  Simply by unclipping the feedline, it goes back to being just a ladder!



In reality, there is no harm to amenity from a ladder that happens to be clipped to a feedline.  It is indistinguishable from a ladder not so connected.  So there is no realistic prospect of anyone being able to force you to take it down.  It should be possible to extend this idea to at least 30m, which takes only a ~7.5m ladder, but do make sure the ladder is secure for windy days!

Initial results on WSPR show that the ladder is putting out a very decent signal at 200mW, comparing favourably with full sized antennas used by others.  I'll post the DXPlorer ananlyses when enough spots are recovered.

Now, I think I had better get ready to lime wash that lovely red gable end again!


Tuesday 11 July 2017

Homebrew Morse Paddle

Recently, I came across CWOps, which is an online-based group promoting the learning and use of Morse code.

I never had the time to learn Morse when I studied the then full radio examination in one go (not separate levels as now), which was quite an undertaking for those without much electronics background (and often felt like it was designed to exclude people like that).  But the attraction of using low power and simple transceivers whilst out in the field means I'd like to learn now.

Apparently, CWOps recommends the use of a paddle, rather than a straight key.  A pity, as I have a lovely, ex-oil rig radio room key that would have done nicely.


So, not overly-enthusiastic to fork out the frankly ridiculous and typically hiked prices for commercial paddles, I set about building my own - helped by plenty of online searching for those who'd done a good job of it without using an industrial manufacturing workshop!

According to many, a single paddle is often preferable to a twin paddle.  I've no idea if this is true or not, but the design is certainly a bit simpler, so that's what I built!



Hardly earth-shattering or novel, but it cost me nothing, other than using junk box parts and waste metal and wood.  It works beautifully, and is very finely adjustable for best performance.  It's certainly a lot better than the minimum price of £65 for a commercial unit, and a maximum well into the £hundreds.