WaveShare 7" LCD Screen

Yesterday, I received my new, small screen for the Raspberry Pi.

I bought this so that my power consumption for a solar/battery shack is cut by 60% (to about 5W) from that of using a full sized screen (around 12W).  More importantly for radio, it also gets rid of the very RFI-noisy large monitor, restoring peace to the HF bands.  The extra space freed-up by the diminutive screen is also very welcome.

The screen is a 1024 x 600 WaveShare 7" (17.8cm) LCD, which I bought for £60 from ModMyPi.  It has a HDMI input, and touchscreen capability. 

Success, but it took me a while to get there!  The very high display quality is not really evident in this photo.

The screen comes complete, but you have to assemble the plastic enclosure, which is machined to a very high standard.  Fitting the whole thing together is quite fiddly, but simple.  You can save a fair bit of money if you buy the screen without a frame.  For radio purposes, the lack of plastic frame often makes mounting the screen easier.

There are no instructions with the screen, which is strange, because it doesn't need a lot of instructions; just a few lines are enough.

Instead, you have to visit a Wiki page for the device.  This is fine, but a little 'Chinglish' in its delivery. 

What is not clear, until you spend hours playing around with the Raspberry Pi's config.txt file, is that the configuration changes simply need to be added at the end of the config.txt file.  You don't edit those values already in the file, which is how I thought it worked.  I think the maker and/or the seller should stick a simple few lines of advice on this in the box.  But margins are so low they don't bother.

For posterity, and to help those struggling as I did, what you have to do is:

(1) Connect your Pi to a normal-sized HDMI screen such as a TV, PC monitor, or recycled laptop screen (the latter idea, with a suitable screen driver from ebay, is a good, though more cumbersome (and non-touchcreen) alternative to the Waveshare, and a little cheaper, that also does not need any of these config file modifications)

(2) Boot up your Pi.  With normal-sized screens, it detects the correct display setttings without user input.  The Raspberry Pi 4B may settle down into correct screen display without these settings, but it might prove unstable; you are much better to change the settings as given.

(3) Click on the command dialog box

(4) Type in sudo nano /boot/config.txt  (note, there must be a space between 'nano' and /boot). 

(5) Immediately below the last command that is already in the config.txt file, (i.e. do not insert spaces or blank lines, but immediately below), enter the lines below accurately:

max_usb_current=1
hdmi_group=2
hdmi_mode=87
hdmi_cvt 1024 600 60 6 0 0 0
hdmi_drive=1

There must be no spaces before or after the '=' sign, and the numbers in the hdmi_cvt line have a space between the 'cvt' and 1024, and then spaces between each number (i.e. hdmi_cvt<space>1024<space>600<space>60<space>6<space>0<space>0<space>0)

If you use the LCD with Raspberry Pi 4 B, you need to remove the line 
dtoverlay=vc4-fkms-V3D from config.txt file

(6) Press CTRL X and press 'Y' for yes to save.

(7) type sudo reboot and press <return>  It may be better to disconnect the Pi from the large display and reconnect it to the Waveshare before pressing <return> 'blind' (without a screen to see proceedings).

(2019 December 23 - REMINDER TO ME: Audio input and output in the WSJT-X software settings should be sysdefault:codec; also on new Pi installs, make sure audio input/output is USB Codec).

One reason for making the instructions clearer is that if you get it wrong, you will have to go and edit the config file on another computer (if you can access the config file, which isn't always the case). If you can't see it on a PC, for example, the fastest turnaround is to quick-format the SD card again on a PC and reinstall the NOOBS files, then insert into the Pi for it to reinstall its OS, then go to the top of the instructions above at number (1).

Once I understood and wrote these lines into the config file, the screen immediately went from being a mess of flashing lines to a full-colour, vibrant display.  Power from a USB 'powerbank' is enough to keep both the Pi and the screen running for several hours, making backpacking a reality.

Other people have commented that this screen has a high quality display, and indeed it does!  Instead of a low resolution display like you get with so many other models, this is just like using a full-sized monitor in miniature.  It isn't a struggle to read the screen at all.

The screen has attachments for the Pi itself on the back, which then effectively gives you a Pi-based tablet, or a small laptop, with the considerable advantage of being modifiable for many practical projects.

One piece of advice for Raspberry Pi 4B applications: the screen comes with a micro-HDMI male to female adapter, which is very bulky and doesn't make for a very robust connection.  I strongly advise you to buy a micro-HDMI male to full size HDMI male cable, which is far more secure and much less heavy on the Pi's HDMI board socket. 

A great product, provided it stands the test of time! UPDATE: I've been using this screen for 4 years now, and it's seen some tough action: left in my /A site for months, which is cold and damp, and also a lot of roughing it in my car with /P seaside operations.  This is a good product!

Like 2011...

Yesterday saw sporadic E activity at least up to 144MHz.  Atmospheric radar showed PMSE above Wales, and powerful thunderstorm activity has been extremely widespread across Europe the past few days.  The solar flux index is also much increased over past months, to around 78.

Strong middle atmosphere radar returns, often related to Es conditions.

This all seems to have conspired to produce one of the busiest days on the upper HF bands I've seen for a long time.

A particularly unusual feature in the mid-evening was very short skip at 24MHz (SSB) between North Wales and the South East of England - clustering at distances of only around 350km.  Unusually for very short skip, the signals were extremely stable and strong, just about everyone being 59 or over.

On WSPR, which I left running overnight, 24MHz reception here remained open until 00:56UT, with my spots continuing to be heard sparsely until 02:18UT.

I didn't work flat out, as it was a lovely warm, sunny day and nicer to be outside.  But I did manage around 70 QSOs across the day, which really did feel more like the last ramp up from solar minimum.
The solar cycle is predicted to increase in activity as early as this summer, so maybe that forecast is now becoming true? 

RSGB: Gender equality a long way off.

Yes, I know.  There has been quite a lot about the RSGB again recently.

I make no excuses for keeping a constant eye on what the RSGB does and looks like, not least because it is the sole representative body for amateur radio in the UK.

Gender equality within my household is good.  We are four people, two males, two females, and the gender proportion of those involved in radio is exactly half.

This seems to be way better than how the hobby appears in public, as presented by the RSGB.  What does that look like?  Well, the society itself can provide exact numbers on membership, and sometimes does.  But people like me have to go on what is presented in public, and use that as a guide to how the hobby appears to the outside world.

Here is an analysis, very simple, admittedly, of the proportion of men and women appearing in images on the RSGB's Facebook page (accessed 25/5/2018), and in the pages of RadCom, the RSGB's monthly magazine.  You can click on the image to make the text clearer:

It's pretty obvious that there's a serious and consistent lack of female representation and/or participation in amateur radio.  We have to be slightly cautious about these figures, because images are not neutral (someone decides when to take them, what they include, etc.) and the selection of images for publication is similarly prone to potential bias (an editor or article writer may like images of men, but not women).

In general terms, we can take these numbers to conclude that there is something that strongly inhibits female participation in amateur radio.  I am not exactly sure what that is.  But it is a clear message to the RSGB, in these times of vocal campaigns for gender equality, that it is failing to make the hobby attractive to females.

If you are female and would like to jet-off on a sponsored DXpedition to some far-flung Pacific atoll, you can pretty much forget it.  The strongest gender bias was in the 'HF' section of RadCom, where none of the photos included anything other than white, middle aged men (18 men, 0 women).

The gender inequality (RSGB website, accessed 25/5/2018) is also very strong at the society's Board level - 10 men, one woman, significantly lower (at 9% female) than the proportion of females appearing in images.

Worse than this, within the same analysis of both image sets, the proportion of people that appeared to be of an ethnic background other than white Caucasian was precisely zero.

According to the Office for National Statistics, the 2011 census showed 14% of the UK population identified as something other than white.

At board level, there is no non-white presence at all.

Overall, it is a regrettable and worrying fact for UK amateur radio, at least as far as its representatives and portrayal in public is concerned, that women have little place in the hobby, and those of non-white identity with no place at all.

Does such a gender bias matter?  Of course it does.

It is simply unacceptable to be somehow, no matter how inadvertently, inhibiting females from taking part in an enjoyable, self-improving, educational hobby.  You can only justify this sort of thing if you want to cling on to believing that females are incapable of participating in and benefitting from a technical hobby like this. 

Sadly, there are some people who really do think this way and I would suggest it is they, not females, who should have no place in radio.  They are the kind of people who tend also to argue that the hobby 'is not meant for children'.  My daughter passed her exam aged just 11 years.  She is a good operator - much better than the 'older' people who tune up, shout abuse and cause QRM on the bands.  Age is not the best indicator of how good a participant you may be in the hobby but interest, a willingness to learn and kindness to others very much are.

We need to look at those numbers, accept them, and start making an effort to present a much more balanced image of radio in public. We need to actively silence as irrelevant those who argue for prejudice and bias to continue.

Some will complain this is positive selection, and indeed it is.  But we are already, wrongly,  positively selecting - for males - by very many, complex means that relate to upbringing, society and expectations.  That needs to change, urgently.

RadCom book reviews - always good news!

I recently came across a blog site that hasn't been upated for many years.  Despite this, it had an interesting criticism of book reviews published monthly in RadCom, the RSGB's magazine (that isn't actually for sale on newsstands, and probably wouldn't sell many if it were).

The site makes the general point that RadCom's reviews of books are rarely, if ever critical of anything much, as one expects with normal, independent reviews.  The post suggests the reviews are unduly positive, always concluding that the books are worth buying.

I should say at this point that I've written book reviews, certainly with plenty of criticism where warranted, for technical magazines over some 25 years.  Many have been used as official reviews by major science publishers.  Only once did a review not get published, and that was because I highlighted the complete refusal to mention, in a book about the Hawaiian astronomical observatories, of the vigorous and empassioned protests by native Hawaiian islanders about desecrating their ritual sites.  It seemed ethnic battles were just too hot an issue for a modern publisher ever-more desperate for advertising income to get involved in.

Of course, unlike many magazines the RSGB sells most of the books reviewed.  Its accounts typically show a large proportion of its income arising from book sales.  There have been several high-profile attempts to boost book sales by the RSGB over the past few years, and books have been seen as a way of keeping the bottom line from slipping in the face of falling and ageing membership.

The blogpost made me realise something that was staring me in the face, but had never really dawned on me. I have sometimes bought books from the RSGB, but often find them repeating material found in other books.  Many illustrations are endlessly republished, apparently being drawn from a central, shared repository of such images and diagrams operated between the RSGB and ARRL.

A lot of the books are written by the elderly, trying to record their WW2 radio and other exploits before they die, for example.  These can be interesting, and indeed should be interesting.  But often, they are very dry and extremely old fashioned and almost unreadable in their style.

It seems odd, therefore, that I have yet to read any such criticism of repetition and lack of novelty in the reviews within Radcom.

I had a look at the two latest editions, and can indeed confirm that the same self-congratulatory, uncritical mindlessness continues unabated, several years after G3XLW's blog post.

Indeed, I had to rub my eyes a couple of times when I read the following in respect of 'Get on the Air with HF Digital' (Steve Ford, WB8IMY/ARRL) on page 56 of the June 2018 edition:

'Although primarily for the US reader, as the book is specifically aimed at HF digimodes, most of what it covers...' 

Huh?  It seems the reviewer believes only US operators use HF digimodes!  Where the hell did that come from?  One can only assume the review author has spent the last 20 years in his shack, steadfastly refusing to use a computer because the only mode worth using is CW.

I think RadCom should use the same process as most other magazines for reviews.  Receive books from publishers, send one to the reader, who then issues an independent review in return for keeping the book for free, no matter what he/she thinks of it.

RSGB and Facebook - bun fight.

Facebook isn't something I use very much, other than to keep up with a very few, generally educational sites.

I do tend to quietly follow the posts that appear on the RSGB's Facebook page, and was interested to see a photo there of a few people in RSGB 'uniform', attending the Dayton 'Hamvention'.

This prompted a small number of comments as to whether this attendance was a financially sensible decision.  The RSGB has, in essence, membership and books to sell.

The RSGB responded, clearly rather irritated by the scrutiny, that the sales at Dayton covered the cost of the trip there.  It later claimed the sales "more than" cover the costs.  We might be forgiven for wondering which of those two is correct, and by how much more than the costs do the sales exceed?  Asking isn't very welcome, it seems.

Such concern about how the RSGB goes about spending its money is entirely justified, because it suffered very serious problems of both financial control and accountability, which were not resolved until as recently as May 2013.  It involved the repaying of an amount, called a 'debt' and a 'financial irregulairty' by the RSGB, believed to have been around £41,000, to the society by its then General Manager, Peter Kirby.

There was also a lot of unpalatable activity concerning the purchase, prior to gaining planning consent, of a large and fabulously expensive Luso tower, which some influential people at the RSGB thought would be a great addition to their new National Radio Centre site at Bletchley Park.

Bletchley, though, is very obviously an incredibly important and sensitive site of global significance, with many listed (protected) buildings.  So it was clear to anyone that there was the very highest hurdle - higher even than the Luso's 12m minimum height setting - to jump before any planning authority would approve a steel lattice tower on this site, no matter how related it was to radio, computing and communication.

Of course, the RSGB eventually found itself in the utterly ludicrous position of having already bought the £31,000 tower, but planning permission for it refused.  The RSGB later advertised the tower (copy text retained here) for "just £13,500", or less than half what they paid for it not very much earlier. 

This kind of activity may well be seen as something the society would like to forget.  It does, of course, need to move on, and has.  Quite drastic changes of upper staff and procedures have taken place since.

But the membership should not easily forget what has gone before, not least because the society dealt with much of this under the cloak of 'minimal comment due to legal reasons', which also conveniently allowed avoidance of further scrutiny, not least how an entire Board of Directors lost control of the ship.

That 'say nothing much' approach may have been legally necessary.  But that is not to say that the RSGB didn't owe its fee-paying members a better, more transparent explanation for how things came to be the way they were around 2011.

How did the RSGB's structure allow £31,000 to be spent before planning consent was secured?  Why was such a gargantuan tower necessary anyway?  Were they the same kinds of structures and attitudes that also led to the financial troubles?  The detail is, for the most part, still unknown - at least to its members.  So they can't meaningfully be learned from.

So, RSGB, before you take offence at people scrutinising your activities, take a good slice of humble pie, and remember how badly things got just a few short years ago.  Better still, make a promise to us all that you welcome constructive scrutiny and criticism - and act on it.

£3499.95

This blog started out, as its header says, to highlight the fact that ham radio does not need to involve huge amounts of money in order to enjoy the hobby and enjoy it effectively.

It also started out to challenge the way things are done, who represents us (if anyone), and promote a more dynamic response to the problems facing modern radio.

I often criticise RadCom, the RSGB monthly magazine, for promoting an elitist vision of the hobby through its reviewing of high-end equipment.

I've written for magazines for about 25 years.  It's clear that 'reviews' are useful and interesting to the reader.  But they are also highly-prized, free advertising for the manufacturer, if not the shops selling them.  There is usually associated advertising set close to the pages containing the 'review' in most magazines.  After all, magazines cannot exist without advertising.  Indeed, they are better perceived as advertising publications, with some articles thrown in between. Facebook's free services in exchange for serving up advertising is not as modern a model as people imagine!

Despite this understanding of advertising, I'm genuinely disheartened, yet again, to find this month's RadCom reviewing a transceiver costing just short of £3500. 

There is a lot of soul-searching that is endlessly repeated about the lack of newcomers and youngsters in the hobby.  With the promotion of products like this through 'reviews', it is hardly surprising that the hobby appears out of reach to so many.

'Entry level' antenna.  Just £4 million (see advert opposite page).

The problems facing the working age population today in the UK are many.  Lack of remotely affordable housing (typical homes for sale now going for between 7 and 10 times average incomes - even the deposits are unaffordable.)  Half the working population in expensive, insecure rented accommodation.  Jobs are insecure, short term, zero hours and/or not very well paid.

With all these problems, £3500 for a hobby radio is, well, obscene.  I can only imagine that, for the immediate future, radio manufacturers are trying to cash-in on those post-war generations that are in or about to reach retirement age.  A bit like expensive 'luxury' ocean cruising holidays came out of nowhere as the population turned white-haired en-masse and looked for ways to enjoy the pensions they 'paid for all their lives' (except, they didn't; pensions of today are paid for from the current working population.  Nobody expected people to have a 50:50 chance of reaching 100 years old and being in retirement for 40 years or more). 

It would be wrong to say that RadCom never reviews the cheap end of the market.  But it does seem, no doubt driven by the money to be made out of expensive equipment, compared to little or nothing from cheap Chinese or other products, not to cover them as much as it could.

There are things like the micro-BITX transceiver costing only $109 as a part-built kit.  I haven't noticed a 3-page review of this yet.  Then again, the small Indian cooperative that makes this unit doesn't advertise in RadCom.  Could there be a link?

In fact, in my view, it would be much better to increase membership fees slightly to cover the cost of a magazine that is not so heavily reliant upon advertising.  Sure, let's have some adverts, but let's also see a much greater focus on just how many effective transceivers and antennas can be made out of everyday materials at very low cost.

LED Montor RFI: the biggest ham radio mystery?

A while ago, I wrote about my troubles with a 21" LG computer monitor (no TV reception circuitry), which produced copious amounts of interference to all bands up to at least 50MHz.

The best solution I came up with was to wind a 10m VGA cable on a wide PVC former to make a choke.  This worked to a degree, but the bands were still simply nowhere near as quiet as they were without the monitor.

I quickly decided to discontinue the use of the £100 monitor as unsuitable for radio station purposes.

During and since those days, I've read the various discussions and blogs about screen RFI.  In fact, given LED screens' popularity in 'NASA-style' ham stations, and that there are so many hams out there, it is a genuine mystery as to why there is not much more discussion about the problem.  I think a lot of it may be to do with the fact that so many people live in RFI-infested areas already.

A search for videos, perhaps to see someone showing RFI on their monitor, yielded no results.

I found a strong element of capacitive coupling with my screen's RFI.  If I brought my hand closer to the screen, or just simply stood in front of it, rather than behind, it would produce much stronger RFI.  I don't know of a potential solution to that problem.  Grounding the screen also provides a handy path for the monitor-generated RFI, which similarly increases in strength.

Most people who claimed to have resolved RFI from screens clearly hadn't.  They had simply added chokes or other measures that only moved the RFI in frequency and maybe reduced its level somewhat, thinking this 'fixed the problem'.  There's a big difference between reducing RFI and eliminating it, especially if you are interested in weak signal work.

When RFI moves in frequency, it doesn't do so to such a degree that it falls magically outside the ham bands.  It just appears in other parts of the band.  So you might find the FT8 section of 20m free of RFI, but parts of the SSB portion displaying very strong birdies.  You can often simulate the 'fixing' of RFI from screens just by changing the resolution.  You may find your WSPR portion nice and free of noise at lower resolution, only to find the RFI is now down at CW parts.

Things that do NOT reduce RFI are:

(1) The PSU. Powering the LED screen from 12V batteries yields the same RFI.
(2) Screening cables.
(3) Grounding the screen and/or cables
(4) Using HDMI instead of VGA cables

Things I found that do reduce the RFI, but not by remotely enough to return to no-screen, RFI-free conditions:

(1) Connecting a random wire to a grounding point on the screen (e.g. connector chassis), causing the chassis to detune slightly. With a laptop screen (HP), I find this detuning is effectively enough to call it a complete fix.
(2) Different positions and distances of screen from transceiver.

(3) Not having your body close to the screen.
(4) Taking cables away from the screen at right angles as far as possible.
(5) An air-wound choke of around 20cm diameter (VGA only; HDMI cables are generally too short for this).

It seems that LED screens, more especially more modern ones, produce high RFI levels across the board.  It doesn't much matter which one you buy.  I've tried our home TV, a four year-old Samsung LED unit, and it also produces the same noise, although at a significantly lower level than the LG, despite being physically larger.

I also found the same capacitive coupling RFI effect with a Nexus 7 tablet connected to a charger.  Whilst it produces no detectable RFI when simply sitting there on a desk, it produces a low but detectable (by ear) change in noise levels when I place my hand near the screen. 

If you have any ideas or example of fixes that actually work and eliminate RFI altogether, then I and many other people would like to hear from you!