Active Loop Antenna, buy a commercial one or roll your own? Part 1.

 If you are in need of a Active Loop Antenna to use with your RX with there are a number of options.

You can buy any number of well known brands for over a 100 GBP or one of the cheaper Chinese designs like the MLA-30+, or you can build your own.

After trying a fair few designs I settled on one, it first appeared around 1984 in a design by G8CXQ.

Below is the circuit as I use it. Q1/Q2 are plastic 2N2222/PN2222 or equivalent. 

T1 is a FT50-43 ferrite ring with 15 bifilar turns of enamelled wire or similar.

A 700C Bicycle wheel with a slot cut across the rim makes a perfect loop. 

I find the best way to construct the circuit is to build it ugly bug style on copper clad board.

Layout the circuit as it is drawn is the easiest way, see image below.

Layout the components out as they appear on the circuit.

Next Image shows it boxed and ready to connect to a loop.

Circuit boxed with banana sockets for connecting to the loop and a 'F' type chassis socket for the coax connection.

Active Loop Antenna power supply

Now on LF/MF/HF these antennas are directional end to end with the null across the flat sides.

But here is the interesting thing, this antenna also works on VHF, especially on Band II FM, but here it is directional across the face of the loop.

So if the loop is pointing East-West for LF/MF/HF, on VHF its best reception is North-South.

I have two of these loops in the loft positioned at right angles to each other. Watch the video to see what happens as I switch between them, first LF/MF/HF and then VHF.

  Another video showing the directional properties on VHF, switching between the two loops on 93.5 MHz lets me receive either the BBC or Radio France International.

'Bicycle Loop' a 18 inch cycle rim is used as the loop.

SDR devices, Fake, Clone or Genuine? Part 1

  Fake, Clone or Genuine? That seems to be the question people ask when looking at SDR devices on online market places.

So the question is what does each of these terms terms mean?

Fake: an item passing itself off as another by using its name etc when in fact it is a completely different device.

Clone: an item that is exactly the same as another in all respects. 

Genuine: An item produced and developed by the originator.

How does this apply in the SDR world?

Well lets take a popular device The SDRPlay RSP1.

The above image shows a Genuine RSP1.

This next image shows a device that uses the same Mirics chipset as the RSP1 

Now nowhere on this device is any mention of SDRPlay or RSP1, so what is it, is it a Fake?

Well no it isn't a Fake because it isn't pretending to be something it isn't. 

Is it a Clone? Well no because quite evidently the device isn't identical to the RSP1.

So is it Genuine? Yes it is a genuine five port SDR device. No it isn't a RSP1, but it doesn't imply it is either.  In fact these new devices are superior to the RSP1, containing many improvements over the original.

A lot of people say these devices steal the intellectual property of SDRPlay because many people use SDRPlay's software to run them, but you don't have to. There are free open source alternatives available. 

Running SDRPlay devices on openwebrx on x64, x86_64, AMD64, and Intel 64 machines

First you need to install Ubuntu 21.10 Hirsute Hippo, download from here Ubuntu 21.10 Hirsute Hippo Once you have Ubuntu up and running we can get it ready for adding SDRPlay support and installing openwebrx.

Install cmake from software.

Open a terminal and run  sudo apt-get install build-essential

Then run sudo apt install git 

close terminal

Download and install the SDRplay API from here: SDRPlay 3.07.1

Open a terminal and install these packages.

sudo apt-get install libsoapysdr0.7

sudo apt-get install libsoapysdr-dev

sudo apt-get install soapysdr-tools

Build and install the SoapySDRPlay module following the instructions here: SoapySDRPlay3

Open file explorer and navigate to /etc/modprobe.d/blacklist.conf 

Open a terminal and run sudo gedit this will open text editor as root. 

Drag and drop the blacklist.conf  file into the text editor and add these lines at the bottom and click save, 

blacklist sdr_msi3101

blacklist msi001

blacklist msi2500

Plug your SDRPlay device in and make sure the SoapySDRPlay installation is working by following the instructions here: SoapySDRUtil

Download and install the OpenWebRX package for Ubuntu following the instructions from here: install openwebrx

Run commands in terminal as root 'sudo -i'

Open your browser at localhost:8073  and cllick on settings and set your device up.

Useful commands:

Stop/Start/Restart openwebrx server,

sudo systemctl restart openwebrx

sudo systemctl stop openwebrx

Stop/Start SDRPlay API,

sudo systemctl start sdrplay

sudo systemctl stop sdrplay

Sample settings for SDRPlay RSP1A in screenshots.

 

 

To install Any Desk on Hirsute Hippo run sudo apt install libpangox-1.0-0 go to /etc/gdm3/custom.conf and find and uncomment WaylandEnable=false

Ham Radio Deluxe V6xxx and that 30 day trial period.

Now maybe like me you like to test things before you spend your hard earned cash on them.
Well if you want the latest version of Ham Radio Deluxe you will have to pay for it, the last free version was HRD Version 5.24.38 back in October 2012.
They do allow a 30 day trial period and after that you have to buy.
Well I found a couple of problems with sections of the HRD suite that I frequently use so informed them of this and they said that it would be fixed. Well by this time my 30 day trial had expired, so how to see if it really had been fixed?
Just removing the program and then installing again did nothing and I wasn't prepared to pay $99.95 to find out, so what to do?
A little bit of registry work is required but not a lot.
In win7 on type run in the search box, click on Run in the results, in the window that opens type regedit  then click OK and the Registry Editor will open.
Click on HKEY_LOCAL_MACHINE to expand it, then click  SOFTWARE\Amateur Radio\ .
You will see the directory HRD User Profile,  right click on it and click Export and save it.
Now right click it again and this time click delete.
Now start Ham Radio Deluxe V6.xx and you be be presented with the first run wizard and another 30 day trial (note using the same call sign as before may only give you 7 days but that's long enough to test).
If like me your problems haven't been solved you will have saved money, if they have been fixed go pay your $99.95 for your licence.
 

How many turns on that toroid? Toroid Ready Reckoner.

Ever needed to know how many turns on a toroid will give the required inductance?
Well below is a Ready Reckoner for just such occasions.

 Click on picture for large size.
Or right click to save.

Guides to using the SDR-radio.com SDRConsole

Over the pages of this blog I will attempt to assist users of the SDR-radio.com SDRConsole V2.x by Simon Brown G4ELI (ex-HB9DRV).

You can find the pages as they appear in the pages list to the right hand side of this page. 

There is a support group for this software you may wish to join 

SDR-radio.com