Radio Pages on MDS975
MDS975 Home Page
My Home Page

Amateur Radio Button
My Station button
Antennas button
Accessories button
Projects button
Data Modes button
Information button
Portable Operating - /P - button
QSL button
RSGB button
Links button
QRM - Home Plug Networking
                        Interference and other QRM
Photos and
                        bits 'n' bobs
Contact button

Weak Signal Propagation Reporting


Site Map

MDS975 Home


Get Your Amateur Radio

Icom amateur radio

Radio Interference

Site Search

powered by FreeFind


Despite going to the trouble of setting up my radios and PC's for data modes, I haven't actually found this aspect of great interest - in fact my PC is rarely switched on in the shack!  I have tended to use a smartphone or tablet to check email and QRZ etc while using the radio.


Then, in October 2014 I found an interest in WSPR ('whisper'). 

WSPR is "Weak Signal Propagation Reporter." The WSPR software is designed for probing potential radio propagation paths using Iow power beacon-Iike transmissions. WSPR signals convey a callsign, Maidenhead grid locator, and power level using a compressed data format with strong fonrvard error correction and narrow-band 4-FSK modulation. The protocol is effective at signaI-to- noise ratios as low as -28 dB in a 2500 Hz bandwidth. Receiving stations with internet access may automatically upload reception reports to a central database. The WSPRnet web site provides a simple user interface for querying the database, a mapping facility, and many other features.

See my WSPR information page here

Other Information

Here is some information in case the digital modes take your fancy!

                        Signalink external USB soundcard
My Tigertronics SignaLink USB sound card

For any transceiver to be able to be used with a PC to decode and send the various data modes that are available for amateur radio use some kind of external electronic interface is required to connect the radio to the computer.

This can be done by constructing a DIY interface that connects the AF in, AF out, PTT and Key connections on the radio to the PC's sound card and data interface, eg RS232 serial port.

To make connections to the radio easier, the ICOM IC706MK2G has dedicated sockets on the rear for this purpose. There is a 6 pin mini DIN socket for connection to a TNC for packet operation, and a 13 pin 'Accessory Socket' that allows all the necessary connections to an external interface unit that will be used for connection to the PC so that all the data modes can be used.

There are a variety of  external interfaces available, but the best value ones seem to come from Tigertronics, and G4ZLP's ZLP Electronics, In this case I happened to choose the SignaLink USB sound card product. This offered me the easiest method of connecting the Icom transceiver to a PC. The SignaLink is supplied with a cable specifically wired for many different transceivers and wiring diagrams are supplied for very many transceivers.

Incidentally ZLP Eletronics have recently released a new data interface, very similar to the SignaLink USB; the "DigiMaster DataLink".  The ZLP "Digi Master Data Link" has a built in USB soundcard but with the bonus of switched socket connections for 2 radios. See for more information.

I bought my SignaLink USB with a cable suitable for connection to the Icom IC706MK2G, of course. What makes the process so much easier than some other products is that there aren't lots of separate cables and plugs to hook up to the PC's sound card input and output and the serial port. In fact the PC does not even need a sound card. The SignaLink takes care of all that on-board and simply connects to the PC with a single USB cable. All it took was a few moments for Windows to identify the necessary drivers and it was ready to configure.

There are some sound card settings to take care of, but the SignaLink instructions covered the necessary details. I do really appreciate the facility of the interface having an internal USB sound card as this frees up the PC's own sound card for normal duties of playing music and movies and other sounds.

The Tigertronics SignaLink SL1+ is an alternative interface that uses the sound card built into the PC (rather than having a built in sound card connected by USB).

G4ZLP produce several similar interfaces the DigiMaster PRO+ and the DigiMaster MiniPRO

                                    DataLink" data interface with
                                    USB soundcard from G4ZLP
"Digimaster DataLink" data interface
with built in low noise USB soundcard
For 2 rigs. From G4ZLP

                                    MiniPRO" data interface from
"Digimaster MiniPRO" data interface from G4ZLP
- uses PC's sound card

G4ZLP USB Sound Cards - Lower Noise than
Tigertronics SignaLink USB

"Digimaster MiniPro SC" data interface
with built in low noise USB sound card
For 1 rig. From G4ZLP -

FreeDV_digital_voice_for_HFFREE DV - Open Source Digital Audio for HF !

FreeDV is Open Source Software released under the GNU Public License version 2.1 - no proprietary software or codecs involved.

Notes for users of the Tigertronics SignaLink USB interface:  The SignaLink USB interface can be rather noisy and suffer with an uneven audio frequency response. Here are some notes that may help users modify and improve the noisy Tigertronics interface :
The ZLP Elelctronis DataLink or MiniProSC may be quieter USB soundcard alternatives :

Some links to Free DV information that may be useful:

RIG CONTROL  -  Computer RS232 Serial Port or Computer USB Port to C-IV or CAT radio interface (TTL):

ICOM IC-706 mk2G & YAESU FT-857D / FT-897D / FT-817 RIG CONTROL INTERFACE - and most other rigs

To use rig control software, such as Ham Radio Deluxe, to control these and other rigs a C-IV or CAT control interface (TTL) will be required. This can connect between the radio's C-IV or CAT port and the computer's Serial Port. This may be inconvenient since not all PC's have serial ports, or if there is one it may be being used for some other function. In which case it would be far more convenient to use a USB port on the PC.

This could be accomplished by using a USB to Serial Port conversion cable such as the excellent "US232R-10 Premium USB-Serial Converter" from This would allow a cable such as the  "Icom CI-V / CT17 / CAT Interface [ CT-17 level convertor ]" from ZLP Electronics for ANY and ALL CI-V Icoms" or the "Yaesu CT62 CAT Interface" from ZLP Electronics.

Alternatively ZLP Electronics provide excellent interfaces that connect between a USB port on the computer to the C-IV or CAT port on the transceiver. This seems to me to be the most modern and elegant solution:

For Icom radios:

The miniature USB dongle "USB CT17 CAT Dongle Interface" or the more substantial "DigiMaster Single USB CT17 CAT Interface". Based on FTDI's 232 chip for maximum performance and reliability and powered from the PC's USB port, these can be connected to the Icom Communication Interface-V (CI-V) port on the IC-706mk2G using the ZLP Electronics I1 cable, suitable for any Icom that uses the CT17 / C-IV ). (This interface can also be used with "Y1", "Y2", and "Y3" cables for Yaesu radios.

For Yaesu radios:

The miniature USB dongle "USB CT62 CAT Interface" or the more substantial "DigiMaster USB CT62 CAT Interface". Based on FTDI's 232 chip for maximum performance and reliability and powered from the PC's USB port, these can be connected to the FT-857D / FT-897D with the Y3 cable to the 8 pin mini-DIN data port or alternatively with the Y4 cable to the MIC socket.

G4ZLP DigiMaster USB
G4ZLP DigiMaster USB CT17-CT62
for rig control
G4ZLP USB Dongle
G4ZLP USB Dongle
for rig control

KENWOOD TS-590S  -  Data and Rig Control

I now also have the Kenwood TS-590s - Kenwood have very thoughtfully included a USB interface into this transceiver. This means that one simple USB cable connects the rig directly to the PC wich provides the data interface AND rig control.

Before connecting the TS-590 to the PC, the Kenwood virtual COM Port driver must be installed onto the PC (Silicon Labs C_210x USB to URT Bridge). Once that is done the USB cable can be connected between the TS-590 and the PC. The PC will then detect the presence of the USB sound card within the TS-590 and install that automatically.

Once that is done any of the well known data software can be used. The rig can also be easily controlled using HRD (Ham radio Deluxe 5) or Kenwood's own ARCP-590 rig control program.


Before it is possible to use any data modes it is necessary to install some software onto the PC that will do the job.  Fortunately there is a wide variety available, much of it free to use. e.g  HamScope, MultiPSK, MMTTY, MMSSTV, Ham Radio Deluxe + Digimaster 780. These free programs have been written by some extremely clever radio amateurs / computer programming experts and have been very kindly offered free of charge for others to take advantage of. Thank you!!

Of course there is also commercial paid-for software available at various price points from reasonably priced to very expensive. e.g. MIXW and SkySweeper.

The Tigertronics SignaLink is supplied with a CD rom containing a huge array of free data software so this saves downloading time. I just chose the software that I needed and installed it from the disk. I found that, as expected, each individual software program also needed a certain amount of configuration too.

As at August 2008 I have merely experimented with a few of these programs. MultiPSK seems very comprehensive indeed, but has a very daunting user interface. Hamscope is quite simple to set up and use. My favourite so far is Digimaster 780 that I use with Ham Radio Deluxe version 5 ("HRD"). Digimaster 780 is very comprehensive and seems quite straightforward in use and has a modern looking user interface.

That's as far as I've got so far, and I will continue persevering with HRD / Digimaster 780 as my favoured digital modes program.

Hamscope screen shot


WSPR :   

Download WSPR from here :    -

WSPR User Guide :

WSPR Spots :      WSPR Stats :     

WSPR Maps :

WSPR Information by G4ILO :

Accurate computer time (within 2 seconds!) is required for WSPR to operate - an Internet Time Sync Interval utility can be downloaded from here. It will allow the PC time to be corrected hourly or daily. I selected hourly:

Digimaster 780 with HamRadioDeluxe:





W1WC's Featured Software page:

FLDigi and other software by W1HKJ & Associates


RS232 Serial Port to USB Adapter Cable:
RS232 Serial Port to USB adapter cable :


The data modes PSK31, RTTY and perhaps SSTV too.


PSK31 seems very popular now. Try using Digimaster 780.


As a short wave listener (SWL) some years ago, I had a bit of fascination with RTTY. Not tdone anything with it yet, but try using Digimaster 780 some day.


Packet has always held little interest, so I doubt that I will be tackling this any time soon.


There are many TV enthusiasts, but I've not tried it and like packet I'm not especially tempted.

CW / Morse Code

I have attempted decoding Morse using Multi PSK, HamScope and Digimaster 780, but so far my experience is that software programs seem to make a lot of errors in that they tend to decode background noise, creating letters and numbers from out of the noise.

I guess the human ear is better for Morse Code - mine being a notable exception, however!

Below is a nice table showing the dits and dahs of the Morse Code.

CW / Morse Code
CW / Morse Code table


So far nothing doing, as far as digital mode and Morse Code is concerned; I guess I just like 'phone' better !

Have a go and I hope you enjoy these mode better.  73.

Mike Smith - © 2003 - 2016

Subjects covered on this page:
Amateur Radio; Ham Radio; Radio; Transceivers; HF; VHF; UHF; Data Modes; Morse Code; RTTY; PSK31; SSTV; FSTV; Amtor; Sitor
Antennas; Aerials; Cable; Coaxial Cable; Twin Lead; Masts; Poles; Propagation; Computer; PC; USB Computer Interface; Microphone
Loudspeaker; Filters; Noise Reuction; DSP; Digital Signal Processing; Morse Key; SWR ; Inverted L; Inverted V; Dipole; Doublet.