SDR and Shortwave Radio                                                              


Shortwave radio is radio transmission using shortwave radio frequencies.
There is no official definition of the band, but the range always includes all of the high frequency band (HF), and generally extends from 3–30 MHz (100 to 10 metres);
above the medium frequency band (MF), to the end of the HF band.

Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere.
Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon.
This is called skywave or "skip" propagation.
Thus shortwave radio can be used for very long distance communication, in contrast to radio waves of higher frequency which travel in straight lines (line-of-sight propagation)
and are limited by the visual horizon, about 64 km (40 miles).

Shortwave radio is used for broadcasting of voice and music to shortwave listeners over very large areas; sometimes entire continents or beyond.
It is also used for military over-the-horizon radar, diplomatic communication, and two-way international communication by amateur radio enthusiasts for hobby, educational and emergency purposes,
as well as for long-distance aviation and marine communications.

Hardware

MSi.SDR



Frequency continuous coverage from 10kHz to 2GHz
12-bit ADC chip
Built-in front end filter
Spectrum bandwidth of up to 10Mhz

Similar to the SDRPlay RSP1 using EXTIO.

Multiband Inverted V Dipole Antenna

The inverted V is a so-called “lazy” dipole that cannot keep its arms up and is about 4 to 5% shorter on each side!
The arms can be made of any type of wire and virtually be hanged anywhere.



Balun 1:1 1-56MHz.
Centre fed antennas with coax (50 Ω) will need a balun to make the line symatric.



Balun of the dipole is at the highest point and the two legs come down to lower points.
The angle between the two legs should be at least 90 °, and preferably 120 °.



Adding dipoles wires for 40m, 20m and 11m bands.
Bands are added in sequence starting with the lowest band (longest wire) at the top.
And the highest band (shortest wire) at the bottom, don’t let the wires touch each other!



PVC spacers are placed 16cm apart of each wire and PVC isolators at the end of the wire.

This for sure will affect the radiation pattern as each wire interacts with the others.
We will have to shorten the legs slightly to get to the desired frequency again.

The inverted V configuration.

Band Length approximate (one leg) Note
40m 7.090MHz
10,10 meter
Support Wire / Cut down to 8.50m
20m 14.2MHz
5,017 meter
11m 27,5MHz
2,586 meter  

Analyze and Tuning




For Analyze and tuning a NanoVNA is used.



The dipole for 40/20/11m seems to performs well.

Note: I am not using this Antenna for Tx.

Install SDR Driver


Install API/HW DRIVER – V2.13 (20TH JUN 2018) from SDR-Play website.

Download SDR#

Download ExtIO for SDRPlay extract and put ExtIO_SDRplay_RSP1.dll in SDR# folder.

Download  SDR#_ExtIO_v1.1.zip  extract and put content in SDR# folder.

Choose UHD / USRP driver inside SDR#.

If you have more than one ExtIO dll in the folder, will ask which one to use.
ExtIO_SDRplay_RSP1.dll is in use for the MSi.sdr

This driver has no limitations and gives a full function SDR#, other mods cripple frequency tuning ect.
Works with 16xx/17xx Versions.

Thanks to Tof!

SDR Software




SDRSharp 1672



SDRSharp 1732


Download ShortWave Info and Scope SDR# Plugins

SDR Meters Plugin

Accessibility Plugin



40 Meter Band



20 Meter Band

SDR Console 3.21



Wefax Transmission.



FT8 40m Gridtracker

Usefull Links


Bulgarian DX-Blog

Priyom

STANAG 4285 DECODING WITH RTL-SDR

STANAG Freqs

Swling Blog

Shortwave Bands

Shortwave Info

FT8 Software and freqiencies

Freq list digf mode

HF Bandplan

FLDigi Wefax Reception

Frequenzen der Wetterdienste

Station Schedules

RadioFax Broadcast

Propagation

Multiband Parallel Dipole

Inverted V Dipole Calculator