An EMI Spy?

 I've bought myself one of these kits from SDR Kits:

It's a german bit of kit marketed by Funk Amateur but sold in the UK by SDR Kits and is called the EMI Spy 2.0.

There's a load of bits and bobs in a neat box:

All of the SMD soldering is already completed, so in reality there are only a few components to solder to the board before assembly:

It went together really easily:

Once complete, there are 4 different antennas or probes you can use for EMI hunting.

This should prove a useful addition! I will report back once I've had time to try it out....

Playing in WPX

 Well,

This weekend is the grand-daddy of all CW contests - the WPX CW test. 

There are many words to describe the bands while this test is happening, my preference would be bonkers. There is CW everywhere - who says this mode isn't popular?

Here's a snapshot from 20M during the test:

I've been having nothing more than a play during some free time, 8.5 hours into the test I was already receiving serial numbers over 1100 - so thats an astonishing run rate from som stations - I wonder if this is really "amateur" radio?

Anyhow, after a few hours play, here is my log as a map:

This tells me that despite my (far from optimal) location, my HF station gets out OK. 

I've been specifically looking for VU7T on Lakshadweep Islands but so far haven't heard the station strong enough to try working him.

Fun, don't you think?

The Art of Rotator Control

 Well,

I watched a video the other day on the TechMinds YouTube channel all about a rotator control board sold by AF6SA.

This neat little board provides a controller for almost any rotator and then allow network control via web or other interfaces - neat!

I ordered one from accross the pond and it duly arrived.

I've put it in a box and set it up to interface to the 6-pin mini-din socket on the back of my Yaesu G-1000-something rotator.

I followed the calibration instructions in the manual and now the display aligns well with the rotator heading... so far so good.

Now to interface to my logging/control software.

More to follow!

More MA6B shenanigans

 Well,

Back in the midst of time, I installed an MA6B from Cushcraft - well, MFJ as they were. Sadly now defunct.

It's been a bit "out of bonk" recently with some SWR swings and I assumed I'd got a feeder issue.

I brought the antennas down and replaced the feeder from the antenna back to the shack - no change.

I then thought it might be the "junction box" in the centre of the antenna which is just that - there's no balun. The box seems to have deteriorated in the sunshine, but electrically it looked ok. Not that then, I don't think.

I found the SWR on 10M (28MHz) was the worst, and eventually I ended up taking the traps off the elements one by one and testing them with the spectrum analyser.

I found one of the CT1 traps to have only one "dip" rather than the expected two - so I think this is the route of my problems. Luckily I have some spare parts so I've just swapped it for a new one.

I'll take it to bits soon and see if I can find out what's actually broken.

Here are the SWR curves after I finished, mainly for the record:

I'll post more if I take the trap to bits - I mught just chuck it in the bin.

TinyGS - A Satellite Groundstation using LoRa (no, not Laura)

 Well,

Unless you have been asleep for a few years, you will undoubtedly have seen people using low cost LoRa (long Range) wireless modules based on the ESP32 MCU for off-grid comms using MeshTastic.

Here's another really neat use of these boards, this time, the 433MHz variety:

These modules are available on Amazon and other retailers in the far east for about 3 bob and a conker. 

TinyGS is a really neat project that allows you to instal some software on these boards, hook up an antennamabob and then receive packets of data from passing satellites. You can then view the data you have received and research the various sats that you have received data from. It's really quite interesting.

My module with the software installed, is currently suspended by a USB cable and a bit of coax in front of a SWR meter:

The range of the RX is impressive:

If you take a recent example of a received packet:

You can then look up the satellite in question:

and read all about its purpose:

The spacecraft is designed to measure the level of electromagnetic radiation in the frequency range of 0.1-18 GHz to create territorial maps of the distribution of these levels as part of long-term analysis and study of statistical measurement results. Remote sensing of the Earth in the optical range, obtaining photographs of the earth's surface with a resolution of ~5 m/pix.

Due to the ability to link the received data to geographic coordinates, the information that the payload module will provide can be used to create maps of the distribution of the level of electromagnetic radiation from the Earth's surface.

So, how about that then?

Pluto+

 I've bought myself a Pluto+ from Bangood. 

Externally it looks the same as I expected, but internally it's different to anything I've seen posted previously:

I set it up following some information on the internet, namely I did the following:

• Installed the windows drivers from here
• connected to the devices COM port using Tera-Term 
• Issued the following commands from the command prompt:

          # fw_setenv attr_name compatible

          # fw_setenv attr_val ad9361

# fw_setenv compatible ad9361
# reboot

This extends the RX range to be 80MHz to 6GHz

I then edited the config.txt file on the devices "flash drive" and added an IP address, rebooted once more and the device now works fine with power and a network connection.

I ran into a spot of trouble when I then updated the firmware to the latest version, no matter what I did I couldnt get the ethernet connection to work. Rolling back to older versions of firmware didnt seem to help. I looked at the original Bangood product listing which had a ZIP file linked, I downloaded the file and found a firmware file which included "g7bdc-dirty". 

I've installed this firmware and the ethernet connection is working once more.

I can't find any reference to G7BDC  or his/her firmware on the internet at all.

A most perplexing mystery!

Messing About With NodeRed

 I'm still messing about with my ideas for QO-100 and I'm now thinking that I'm going to make a remote box of tricks that will be connected by ethernet to the house.

The main SDR will be the Adalm-Pluto which will give me the full duplex I need for TX on 2.4GHz and RX on 700 ish MHz.

Inside the box I would like to be able to monitor the health of the various power rails I'm going to need plus I would like to be able to switch a few things on and off.

I've started to look at NodeRed - a most excellent piece of software that can allow me to create a dashboard to do just about all the things I want. This can run on a Raspberry Pi in the remote box of tricks and get controlled by a dashboard from a web browser on the network elsewhere.

So far I have installed the software on a Pi5, tried a HID relay unit, which needed this jiggery pokery completed before it would work:

Linux Dependancies

For linux you will need to make sure you install some additional libraries. For debian and raspbian this should be done with the following: sudo apt-get install libudev-dev librtlsdr-dev libusb-1.0-0-dev libpthread-stubs0-dev git

You will also need to add udev rules. Create the following file /etc/udev/rules.d/50-hidrelay.rules. This allows node-red the permissions to commuincate with the device directly.

SUBSYSTEM=="input", GROUP="input", MODE="0666"
SUBSYSTEM=="usb", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE:="666", GROUP="plugdev"
KERNEL=="hidraw*", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE="0666", GROUP="plugdev"

I now have a simple flow graph in Node Red:

Which creates a simple dashboard with some buttons:

and these buttons, do indeed switch the relays on and off.

I've ordered some INA219 boards, these are voltage and current monitors that will interface to the Pi using I2C. There is a module for these in Node Red so should be able to create voltage monitoring OK with these devices.

More to follow!