Sunday 30 August 2020

GPS QSO aid, Position & Time and Clock

I have been busy. It has always seemed to me that a GPS could be useful in the shack and in the field, So I have developed a very simple piece of hardware and a sketch to give 3 views of GPS data.

A GPS receiver can give you, amongst other things, the date, the time and your position in latitude and longitude. These things can be useful to the radio amateur, date and time for logging QSOs, and lat & lon translated to Maidenhead Locator for your stations position. 

I have chosen to display 3 different views, like this

The first is a display for QSO use, the second the raw GPS data and the third a conventional clock. All times are in UTC as this is GPS basic time.

BLOCK DIAGRAM / CONNECTIONS

After this digram was drawn I added a three way toggle switch connected to UNO pins A2 - GND - A3. This selects the type of display to show on the OLED display.

SOFTWARE
The software needed for this project is on my web site M0IFA.me.

1. The sketch itself is called GPS_HAM, copy and paste it into a new Arduino sketch and save with this name.
2. An Oled header file which gives the initialisation and  a set of functions based on the public u8g2 library for displaying text, numbers, clock hands, dates and times (and lots more if you need them). Put this is a folder called Oled in your libraries folder
3. The u8g2 library, which you can download from the internet, or copy from my site libraries
4. The Arduino SoftwareSerial and TinyGPS libraries which, again, you can download from my libraries.

Put Oled, SoftwareSerial and TinyGPS in their own folders in your local "libraries" folder.

BOX IT
I have ordered a small plastic box in which I will mount an Arduino Nano (replacing the development UNO I used), the GPS antenna and NEO-7 module and the OLED display. It will be powered from a 12V supply to the Nano which will them power the OLED and GPS.


Saturday 22 August 2020

Time to tidy up our SSB transmissions

I have been astounded at the quality of SSB transmissions that are revealed by today's SDR receivers which show both a waterfall and a band spectrum. These are as seen on Hack Green SDR WEB receiver.

When I focused in on different transmissions I find

1. GOOD MODULATION

Beautiful, clear, full audio bandwidth, excellent audio processing.

2.  VERY BAD SPLATTER, PROBABLY DUE TO OVER MODULATION

Very poor and over modulated transmissions two on both sides and one on one side only. These transmissions often received reports of "good audio" which just shows that the quality of SSB transmission cannot be judged by just listening.

And it can't get worse than this

Just as he said "thanks for the report on good audio". Report "no audio artifacts", needs to use an SDR.

3. BOGGLED TRANSMISSIONS


This is about the worst in terms of quality. Patchy audio EQ, severely bass heavy and muffled and an outstanding transmission of a faulty transmitter or a wrongly used audio processor, giving a transmission of more than 9kHz wide!! This gentleman received a report of "clear, good audio"!!!

Then check this out. Two guys talking about "I like to focus on audio..." Here's the same guy again at 9kHz wide and severley distorted at the top end.


SDR BW is 3kHz, so top one is 4-5kHz wide and the bottom one more than 9kHz!!!

AND ACROSS 80M 


Very mixed quality of signals. Lot of audio processing and poor/good microphones?

NEW CODES NEEDED

The regular reports of 5 and 9 are not good enough. We need a better reporting system - a bit like SSTV which reports 5 & 9 plus video quality.

Tuesday 18 August 2020

Remarkable WSPR results

 I know a lot of you will get spectacular WSPR reports. But for me this is remarkable


20 meters last 12 hours overnight

It is remarkable because I have only a small, low cost 60cm loop antenna, indoors, attached directly to the back of my SDR (ELAD FDM-DUO) and it is set to 4W output!

WSPR is a truly incredible signaling system.


OTA updates for radios

RADIOS ARE ALL SOFTWARE, THESE DAYS

For years it seems our computers have been support by "pushed" software updates. Be it a smooth Apple Mac update or a clunky and intrusive Windows update. Over The Air updates of both operating systems and applications are almost universal amongst professional OS and software sellers.

OK, so commercial forces do come into play. You may simply get an email saying a new version of the software is available, pay up to get it - couple of clicks and PayPal does the trick! Or on the other hand you may simply wake up one morning to a small notification on your Mac's desktop saying, new xyz has been installed while you slept or in the worst case "Restart to install" for a new version of the MacOS.

Whatever software vendors care about you and support their products with easy updates.

NOT SO, RADIOS

But for our radios that depend more and more on complex software, nothing. No updates. No emails. You have to search the vendor webs sites or be on a news group to find out that your version of the DSP  software has been upgraded. Then it is an almost impossible task to download it and install it in your radio - and if it goes wrong and you end up with a brick, then the only solution is to send it back for repair, and pay.

As ELAD, makers of my excellent FDM_DUO SDR said, the radio has no WiFi interface and we have no plans for it. Oh, come on. What does it take to install an ESP32 WiFi chip in a radio of this inherent almost 100% digital complexity? Nothing but a management decision. And proper customer support.

MAKERS wake up

This is simply not good enough. All major vendors of radios need to develop a service which goes along with their products that automatically and freely keeps them up to date and performing at their best. You pay a lot of money for a new radio these days - thousands of pounds - and this must include software updates that are transparent and automatic.

ICOM EXAMPLE

This is what ICOM says you have to do, clunky or what?

"To update the firmware 

• An SD card or an SDHC card is required. 
• Format the card in the IC-7300 before using it for the update. (First, save any data that is on the card, if necessary.) 
• Unzip and save the downloaded firmware file in the“IC-7300" folder that is on the card. 
• Save the transceiver’s data onto a separate card before the update, as it is possible that your data could get lost or corrupted during the process. Thoroughly read Section 8 (USING AN SD CARD) in the FULL MANUAL for details. 
• Thoroughly read Section 15 (UPDATING THE FIRMWARE) in the FULL MANUAL before starting the update. 
• Never turn OFF the transceiver power during the update. "

AND YEASU?

"Caution!
Please be sure to confirm the model and the version of your transceiver before starting the update. Writing incorrect firmware to the transceiver may cause abnormal operation or failure. Do not install this version firmware to any FT1XDR/DE. The update firmware is NOT compatible between FT1DR/DE and FT1XDR/DE.

Refer to the firmware update procedure instructions in the help files (.pdf files) inside the ZIP folders.

Refer to the firmware Update Instruction Manual in each ZIP file."

How terrifying is that???

Friday 7 August 2020

ELAD Blueduo

BLUEDUO - remote operation of the FDMDUO SDR 

One of the programmers of the ELAD FDM_DUO SDR has worked with ELAD to create a very interesting application. This is called BLUEDUO and is a bluetooth connection to the  SDR which allows remote working. The only thing it does not provide is remote sound in or out... which I guess is due to the comms speed of Bluetooth being to low to handle both the tuning and spectrum data as well as audio.

The Blueduo software is a Google Android app available on the ELAD web site. To try it out I have

1. Begged and borrowed an Android tablet from my son - who has everything

2. Purchased a Bluetooth dongle, HC-05

3. Used a FT323 USB <-> Serial TX, RX dongle I already have to program the HC-05

4. Downloaded the software "apk" file from ELAD, and installed this on the tablet - for this you need to download it, use the tablet file manager and give permissions under settings to allow non-Google Play Store apps to be installed. But then it is just a matter to double clicking the downloaded file to install it.

5. Bought a DB9 male plug to connectors flat cable (There may be other sources, it was very difficult to find!)

BUT FIRST, PROGRAMMING THE HC-05

The FT232 pins connect to the HC-05 as follows

FT232  HC-05

GND -> GND

VCC -> VCC

RXD -> TXD

TXD -> RXD

The HC-05 has now to be programmed. Wire it up as listed above. 

When delivered the HC-05 dongles almost certainly come with their baud rate set to 9600 or 38400 baud. Connect the FT232 by USB to your computer - mine is an Apple MacBook. I use a serial terminal app called iSerialTerm which can select the USB port, select the speed 38400 and start a connection (There will be Windows terminal apps, but I don't know about them). Set the "Send" format to be your typed commands followed by a CR/LF (/r/n).

But first disconnect the HC-05 Vcc, press the small button and hold it down, then reconnect the Vcc to get into program mode. Showed as a slow flashing LED. 

Now check the HC-05 is responding by sending a command.

AT+VERSION?

to which it should respond with its version number. 

When you have a correct response enter the following commands - you may have to repeat entry to the program mode before each command is given - I did...

AT+NAME = BLUEDUO

AT+UART = 115200,0,0

AT+PSWD = 1234

This will set the Bluetooth dongle name to BLUEDUO, to a speed of 115200 baud required by the FDM-DUO and a Bluetooth password of 1234.

WIRE UP THE HC-05

Now you can remove the FT232 connections and make connections to the 9pin connector of the FD-DUO.

Pin side view

Check with a meter the pin to cable colours to find the correct connections to use. Mine were like this

HC-05   FDM-DUO (9pin)

GND      pin 5    WHITE

RXD      pin 6    RED

TXD      pin 7    YELLOW

Vcc      pin 9    GREY

Plug the 9pin into the radio. Use your Android Tablet and join the Bluetooth connection BLUEDUO and give the password 1234 you set above. Start the Blueduo app. And bingo a display of the spectrum and waterfall and lots of buttons to control the SDR.

Finished interface


LOOK AT THIS

FDM-DUO on 20m WSPR TX
USB Peak at -5dB, LSB at -65dB

One interesting point. When using the Blueduo display it not only shows the received spectrum but also your transmitted one. Where, for example on digital modes, you can see the transmit peak signal, but also to the side the other sideband up to 60dB down, and any high modulation harmonics USB which may indicate over modulation of the digital USB sound input.