Saturday, 16 October 2021

WSPR and antenna update

 My Al-705 loop antenna has the capability of one, two or three loops. I will make a series of tests of WSPR reception with these option. But for now I have a three turn loop and you can see the difference on 30m compared to one turn here:

The day I changed over (with the narrow gap in transmission)
and the subsequent increase in spots with 3 turn loop

On the right side you can see the last three days, first has a gap where I disconnected the loop, bumped it up to three turns to try 40 & 80m reception, then I restarted 30m WSPR with this three turn loop. And got the surprising result of much higher spots. Which really shows in day two on the right. Day three is just coming up, it now 08:30 UTC. 

Transmission is currently down as my son is visiting and the shack is his bedroom!

Friday, 8 October 2021

Club QO-100 transmitter

An uplink converter (here) for transmitting to the QC-100 satellite has been built by numerous amateurs

This is the layout with individual "ebay`' items fixed to a mounting board, interconnected by SMA cables.

The Banbury Amateur Radio Society is building one of these along with the TX/RX antenna and LNB. So far we have connected up the units free across the table, and are feeding it a 432MHz input at up to 10W through a 20dB attenuator. Awaiting PSU module for +8 and +5V. No results yet, but will document as the project goes ahead.

So here's the project going ahead - it is NOT a shambles, promise

Some of the modules scattered around

And proposed box which will go outside near the dish

Just a couple of new photos as we have a club presentation about the Ofcom EMF checking we all have to do: spreadsheets and all that. I think I am exempt with max 5W TX and indoor loop antenna! Or also with my 200mW WSPR TX.

We have a receiver going with a commercial LNB and dish, but it drifts quite a lot and we must xtal stabilise it. We are using an SDRplay with SDRUno software to tune to the LNB output on 739MHz. There is talk of moving to an RTL dongle and I would like us to try GQRX software...

The tuning and TXRX frequencies are

I am thinking about GQRX as this runs on the Mac. With an RTL dongle SDR. 

In GQRX you can set the offset frequency when using a transverter. For QO-100 reception the LNB LO is 9750.0MHz for "reception" at 10,489.675MHz. 

Friday, 24 September 2021

WSPR info & results

 My slides of a presentation on WSPR to Banbury Amateur Radio Society are here.

The results using the QRP- Labs U3S TX can be seen if you install WSPR Watch (phones or Mac OS) looking for my call sign M0IFA on 30m. Suggest to load 1008 spots (about a week's worth).

Gap on the right is when I unplugged to go visit the club house
to give the presentation (locally and over Zoom)

Friday, 3 September 2021

Field day 4 Sept 21

Saturday 4th Sept was Field day and Banbury Amateur Radio Society (BARS) went to Balscote Mill to put up a /P station.

I also went along to put up my ELAD FDM-DUO and an AL-705 loop antenna.


I have updated my old MacBook 12" to run Windows 10 Pro and install the ELAD FDM-SW2 SDR suite. Looking to make any contacts on 40-30-20m.


I switched to my new MacBook Air and WSJT-X and try for FT8 contacts.

Most of the day was a disaster. We were located in a deep dip with little take off. I was heard in Croatia but no contact confirmed. The main station's G5RV  antenna broke in the centre and was irreparable!

Our needs for EV charging by 2030 (9 years away!!)

 Chucking out the peanuts

Day after day our government is announcing this and that million pounds for peanut initiatives for the upheaval change we must make to move to Electric Vehicles.

What about 2030, just 9 years away? Will there be 6m or 18m EVs on our roads? It varies depending which part of government you ask, BEIS/Dft or Ofgem. So what? It's just chicken and egg. And here most definitely the chargers come first, for without them along our strategic road network EVs will not come, people will not buy them.

We are faced by seemingly random government actions. "190,000 home/work chargers of 7kW power by ???" "25,000 chargers, unspecified, and without declared funding, by ???" Magnificent £1.3bn declared over 4 years, for what? Not defined, but turning out to be handouts to cowboys operations putting chargers in the wrong places like McDonalds or Chester Zoo, not along our roads. Lots of talk about "£950m for rapid chargers on our roads, 6000 by 2035" (far too few). Plus a miserable £20m for Local Authorities to divide their car parks and prevent fossil fuelled cars equal access to parking, oh, and some unspecified "street" charging in 2021 & maybe 2022...

Like I said, chaos.

Pools, chargers and points

And on top of this Boris's stated bold angelic vision of charger pools "every 30 miles along our Strategic Road Network". Which, when you work it out, means 2,300 miles of motorways needing 80 charge pools, at which at least 20 pools with 10 chargers each or 9,300 points.  And even then 15m EVs will need up to 15m home/work fast charge points. We have to deliver the power, a mean of 1kW per EV by 2030 is the EU estimate for electricity suppliers.

But this is not the direction things are going. Is it? The government firmly believes in the approach of "the market will provide" (read: it's not our job, we are only the government). But the market  will not. Today few of the chargers are finding their way to motorway pools and very few, if any, to "A" roads. They are being installed at local destinations, supermarkets, fast food outlets, in town car parks. The result of which will simply be huge traffic jams as people drive in and out to put energy in their cars. And as EV's fight ICEs for a parking place.

And again just think, EVs need a 45-60 minute charge (it is getting faster but not until better battery technology comes along) versus fossil fuels cars needing just a 10 minute stop. Or 6 times as long. And the range of the EV is, not as makers claim 200-250 miles, but a realistic 150 miles, or lower in cold weather, versus a fossil fuelled car of 500-600 miles. Or four times smaller. This means many more EV stops and many more chargers. It is obviously foolish to think of just replacing petrol stations with EV charging stations. A new architecture of a revolutionary Travel System is needed, only achieved by good top down thinking and planning.

This is where our government is failing us.

It seems the only company that knows this is Tesla, with its manufacture of batteries, cars, of  navigation systems that route you to/via chargers and of an adequate national charger network.

Bad place

So where are we today? In a bad place. The useless national data base of chargers, on line as Zap Map, shows puddles of chargers. Except when you drill down to find one you need right now, right here, for example in East Anglia desert. There are more vast desserts when none can be found. Worse still are the fifty different "networks" run by 50 different cowboys, all given handouts by government to put chargers anywhere they want. All branding no substance. 

No plan, no hope.

The government financing model of handouts to stimulate private initiatives will not provide a pan-national charging infrastructure. What it promotes is seed money promoting sharing of costs with destinations. You know, "come to McDonalds and eat as we provide Rapid EV charging"... In other words the focus of the private investment is shared with destinations. No destination, no chargers. And worse, the paltry sums handed out to Local Authorities most of whom have no idea what to do with it, who employ "consultants", more cowboys, then sprinkle their patch with useless EV only parking. Some even refusing to provide on-street points for those without a private drive.

Sunday, 22 August 2021

How I got WSJT working under MacOS Big Sur

First download the latest version of from 

Then execute the ".dmg" file, this will open the install page. Drag the WSJT app to your apps folder. Then open the Terminal and do this: 

1. List long the file supplied on the download volume

ls -l /Volumes/WSJT-X/com.wsjtx.sysctl.plist

-rw-r--r--@  1 antonywatts  staff  543 28 Mar 12:53 /Volumes/WSJT-X/com.wsjtx.sysctl.plist

As you can see it has the "@" marker indicating special attributes, and has the wrong owner and group. The file as needed in /Library/Daemons is

-rw-r--r--  1 root  wheel  543 21 Aug 15:18 com.wsjtx.sysctl.plist

2. Copy the file to the correct location

sudo  cp  /Volumes/WSJT-X/com.wsjtx.sysctl.plist  /Library/LaunchDaemons

it has special permissions set - as seen by a '@' after the mode, as well as the wrong owner and group

-rw-r--r--@ 1 antonywatts staff ...

3. After copying the file to /Library/LaunchDaemons both issues must be solved. First change your directory

cd /Library/LaunchDaemons

and list the files using

ls -l

where you will see the things that are wrong with the .plist: the "@" and the wrong owner and group

4. Remove the special permissions "@"

sudo xattr -c com.wsjtx.sysctl.plist

and check that is has gone with another

ls -l ...

5. Set the correct owner and group

sudo chown root:wheel com.wsjtx.sysctl.plist

The result should be

-rw-r--r--  1 root  wheel  543 21 Aug 15:18 com.wsjtx.sysctl.plist

6. Now restart your Mac and check the settings with

sysctl -a | grep sysv.shm

If shmmax is not shown as 52428800 WSJT-X will fail to load with an error message: "Unable to create shared memory segment".  And you have to fiddle around a bit more.


I just bought a new Apple MacBook Air (M1 chip). On this the installation went more smoothly. I copied the com.wsjtx.sysctl.plist file across to /Library/LaunchDaemons (see #2 above). It arrived with right owner and group and no special permissions, and then I restarted the MacBook Air and the sysv.shm value had correctly been  updated.

So WSJT is right at least for new MacBooks.

Monday, 16 August 2021

Antenna switching unit

Ok so I have one decent antenna - an indoor AL-705 loop. But I have three things I want to connect it to

* My ELAD FDM-DUO SDR transceiver, possibly via my MAT-125E auto ATU

* My QPR-Labs QCX+ WSPR transmitter

* My NanoVNA, for tuning and checking the SWR to the loop

So I am building a switching unit. And for fun I am putting in it a stupidly simple resistor SWR bridge, with LED indication for high/low SWR which will also help with loop tuning (in addition to the power meter described below which still is, for now, the best way of optimising the matching)

Here it is. Without the three way switch which will mount on the right & I have ordered but which has not yet arrived

The red switch bypasses the small SWR bridge. I chose this green LED after trying a bunch from my scrap box as the brightest of the bunch, there was a notable difference between LEDs. I have standardised, good or bad, on BNC connectors, they are so quick and easy to plug/unplug when fiddling about.

Project finished, works great, now can switch antenna from ELAD for FT8, U3S for WSPR and NanoVNA for tuning