Friday, 16 March 2018

/P Looking good!

A nice warm day today, and a quick chance to finish some wiring and test out the system on SSB.

Using a 1/4 wave elevated vertical, conditions at 14MHz were pretty good compared with a few days ago.  I managed a contact with WD8CCC on 60W PEP, and a very strong contact with Ukraine.  The shack walls and ceiling are a little too lively, producing a distinct echo in my audio, but some plastic foam sheet or old carpet will sort that out!

The 100W panel was brought into action as I operated, and proved to keep the battery in very good condition.

I have yet to choose a high quality charge MPPT charge controller, using a second-hand waterproof PWM unit from Photonic Universe to get me going quickly at low cost.  I am have also not yet fitted ferrite rings to reduce cable-mediated RFI.  I am happy to say there is only a very weak level of pulses during rapid changes to solar intensity (when clouds drift in and out), and cause no problem at all.  In steady light, there is no discernible RFI.

For more local readers, don't worry - no radio or other expensive equipment is left in the hut.  You may also come across a shotgun-carrying farmer.

Wednesday, 14 March 2018

Antenna connections: mind your material.

If you like ham radio, there's never long to wait before you need to repair or replace antenna connections.

For many, and that certainly includes me, it is often easiest and cheapest to make connections to, say, a balun by using ring or spade connectors that are widely sold for automotive and general purposes.

These connectors are very good, and usually made of plated brass or similar alloy.  They do, though, have poor mechanical strength, so any wire tension has to be taken by a relief loop, and not the connector. The connectors have good resistance to weather, but do corrode.

Last week, I was sending some signals on 10MHz with my half sloper for that band, connected to a 1:1 balun at the tower.  This wire is normally very well-behaved, but had recently started to produce brief SWR spikes, although these were not to very high levels.

The wire I used for this initially experimental antenna that became permanent was quite thin, multistranded stuff, but with a very heavy duty PVC coat.  I decided to change it, as SWR spikes usually indicate the wire starting to come apart within the PVC.

Probably OK, but stainless won't suffer this corrosion at all.

I haven't bothered checking if the wire really was decayed, but one thing is clear: the ring connector suffered quite a lot of corrosion after a winter out in the windy, salt-laden air of coastal Wales.

The part protected by a washer and nut was quite clean, but there was also a small part where insulating tape projected into the washer area (on the other side to the one in the photo).  This could have contributed to or caused a momentary loss of connection.  For some reason, I hadn't used the stainless steel ring connectors that I already had.

So if you are planning on an antenna repair or replacement as the weather warms up, make sure you use stainless connectors throughout.

Saturday, 10 March 2018

APRS Messenger for HF - is anybody there?

Thanks to my blogger colleague Bas, in the Netherlands, I have been getting to grips with APRS Messenger software for HF recently.

This looks like an interesting new addition to the range of activities with HF radio.  But I am not really sure what the software is actually for.  I guess it is somehow 'disaster'-related, but I am not a US-style Prepper, and don't expect ham radio will save us from annihilation if Kim Jog Un presses his little red button.  There will, after all, be nobody left to communicate with.  Also, nuclear detonations are known to severely disrupt the ionosphere to the point where propagation will be, at best, tough.

This is what N8PJ, who runs, has to say about emcomms:

"The continued claims PACTOR-4 serves ECOMM (Emergency Communcations) is a ruse, a falsehood. There are so many alternate 'free' commerical communications paths available that it renders the argument that "Ham Radio is a viable alternative for emergency communication" a joke. Much more reliable communications alternative are available today."
Never mind.  I still have my rig...

For now, the biggest problem with APRS Messenger is that it seems rather deaf.  I have seen a few signals on the waterfall, but over three days or so, I have only seen the software decode two stations - OH8STN (once) and K1CKK multiple times.  Including the US station, this seems to be good going, compared to many, who don't seem to be decoding much at all.

The problem seems common to most.  A discussion group tells of the troubles thus far with this, admittedly experimental and under-development program.  Another blogger also has tales of woe.


I've uninstalled the software, unsubscribed from the related Yahoo! group, and left the author to sort the program out, which he now admits is "not 100%".  

From his postings online, he seems to expect everyone's rig will be so well frequency calibrated that they might match a physical standards laboratory's levels.  My rig is +4Hz out on 10MHz, +2Hz out when averaged across all bands.

Any mode that, unlike the plethora others, demands absolute accuracy from what are, in the end, consumer-level electronics, is missing the point and doomed to failure - which is what Messenger appears to be undergoing right now. 

And why, pray tell, would I bother wasting time on a mode and software that has little purpose and doesn't anyway work, when I can turn to countless other modes that do?

Shack is GO!

After weeks of getting the place ready, and a final connection to earth, the getaway shack is finally producing some warps in the fifth dimension (if you subscribe to Kaluza-Klein theory and its string theory derivatives!)

Using a 1/4 wave vertical and only 40W PEP in very poor conditions, I managed to work EA88ARI/P, very efficiently working a big pileup as he activated La Palma peak VGTF-053, Fernando Porto, under the DVGE scheme, the Spanish equivalent to IOTA.  Radio is a great way to practice language skills, and I never pass up a chance to speak Spanish, though this recording is only of the received signal, not the QSO:

After the QSO, I connected the 100W PV panel that is for temporary, but more rapid charging during operations than the permanantly-connected (but switchable) 10W trickle charge unit produces.  Even in very dull conditions, this was doing a great job of taking the battery back up to full charge in just a few minutes.  Nice also to see that there is no discernible RFI, at least on 14MHz, from the PV system, even without any ferrites installed as yet.

This is how things now look.  It appears pretty rubbish on the outside, but is structurally sound and remarkably warm inside, thanks to a thick heat-absorbing concrete roof, and water only a few centimetres below the building.

Wednesday, 7 March 2018

Kevlar and Sheep!

Over the past week, it has been, for the UK, remarkably cold, with a very strong and days-long wind of up to 90mph in places.

In readiness for the wind, I had quickly taken down my 1/4 wave vertical for 20m a day or so beforehand, laying it down on the side of a ditch, where I thought sheep would not get at it.

After the storm had subsided, I went back to the marsh site to do some work on the shack.

Apparently, green plastic-coated kevlar reinforced antenna wire looks like a tasty piece of long grass to sheep, who promptly took to nibbling on it!  The brutally cold conditions also meant the sheep took shelter against the shack.  I had fixed the small solar PV panel low down, so as to avoid long lengths of vertical RFI radiators.  But the sheep found this very interesting, and had a very unsuccessful attempt at eating that, too! 

Sheep's teeth have no problem cutting through kevlar, as this (very rubbish) photo of one of my radials shows:

Tasty.  For a while...

Still, this is what field activity is all about, so a quick attachment of some spade connectors, soldering the wire and crimping onto the kevlar and coating makes for a perfectly good connection.

Trickle charge PV panel (10W peak), now a bit higher!
I've now fixed the trickle-charging PV panel higher up, where it should be out of reach even of cattle, which will no doubt appear in the fields soon.  The main, 100W panel, only goes out during operation, or after a heavy period of use.

Now for a glass of wine!

Tuesday, 27 February 2018

A positive day!

Too much grumbling recently!

Today has been a snowy old day, but quite sunny this afternoon.  So I took the opportunity to complete my small solar PV system in the new marsh-located shack, which was much warmer in a sheltered spot from the bitterly-cold, easterly winds than at my home QTH.

I had bought a 100W panel, and this will be fine when I am actually operating and want a top-up to the battery life as I transmit, or a fairly quick charge after some longer periods of transmitting.

But for keeping the battery in a good state of health when I am away for some days, I decided a 10W unit would be much preferable, not least because it is less visually intrusive, and less likely to be damaged by the odd straying sheep or cattle!  This small, fully weatherproof panel was only £17, making it cheaper than most (non-weatherproof) 'battery conditioners' with only 2.5W peak output.

So the 100W panel will simply be deployed as and when I need it, propped up against a post and frame I have installed to keep it steady and aimed to the south.  For now, I have kept costs to a minimum, and used an existing, new 70Ah flooded battery to get going at the shack.  I replaced that, for my home solar PV DC system, with two 15Ah scooter batteries in parallel - costing just £35.  Eventually, I will buy a couple of good quality deep cycle 110Ah batteries.

By 2pm, the battery was connected up, and charge was flowing nicely into it.

All I need now is a new, cheap laptop and soundcard interface for some digital work.  Until then, it will be a bit of SSB, for a change...

Monday, 26 February 2018


This morning, something has changed on 20m, and it's not a good change.

FT8 is a mode that has attracted instant and widespread appeal, providing a quick way to fill the logbook.

Filling the logbook, it seems, is what most people want to do in radio.

What they are also doing is turning what have been relatively disciplined band plans into a 'wild west', 'transmit from the hip' type of radio. 

The change that I saw this morning was the appearance of FT8 up to 3kHz above the nominal QRG for that mode of 14.074MHz.  This takes it not only across the traditional JT65A portion of the band, but also the JT9 section.  Those modes suffer badly in the face of QRM from FT8.

FT8 is without doubt a very useful mode.  But it is rapidly killing the attraction of radio for me.  At this rate, it won't be long before vast swathes of the bands are taken up solely with FT8. 

Control of the bands needs to be reviewed in the light of these fast changes in digital modes.  But national societies are notoriously slow to realise there is something that needs addressing, let alone actually getting around to doing it.

Personally, I think new modes that clearly have the potential to be very widely adopted should go through some official process that identifies where problems may arise, and deal with them before the mode and associated software package is put on general release.  The disruptive ability of these modes is simply too great to be left to the developer or associated groups to dictate terms.