Thursday, 2 November 2017

CAMJAM EDUKIT-2 Sensors (Thermometer)

2 Sensors

Having visited the Egham Raspberry Jam on a few occasions I decided to see if my 9 year old Son Oscar would be interested in having a go at Python and using the EDU KIT and learning how to read the temperature from the thermometer and convert it to both C and F on the screen. 
Thermometer coding

This si the worksheet showing the circuit for the thermometer, the lights and buzzer are left on the board, but are not initially used or needed.

The above video shows the thermometer running and the output on the screen in C, holding it in my hands you can see the temp rise and then fall back to room temp

CAMJAM EDUKIT-2 Sensors (Lights and Buzzers)

2 Sensors

Having visited the Egham Raspberry Jam on a few occasions I decided to see if my 9 year old Son Oscar would be interested in having a go at Python and using the EDU KIT and learning how to control lights and buzzers and various sensors. After following the initial code We played around and made the lights flash on and off, one on two one etc and the busser. This is a great way to learn some simple python code and see it interact with physical components. Highly recommended!

Lights and Buzzers coding

This is the worksheet downloaded for the CamJam site above showing the circuit. The code can be downloaded or typed in from the sheet. 

The Video above shows the 2 LED lights and the buzzer and what we did by playing around with the code to show various functions.

Wednesday, 1 November 2017

AMSAT UK Oscar Magazine publishes our July ISS success

Chertsey Radio Club 

Hello, my name is James Preece (M0JFP), I am part of Chertsey Radio Club.

Over 3 weekends in July there were several amateur radio experiments run from the International Space Station and I would love to share with the BBC and the general public what has been happening, hopefully this will encourage some people to look and have a go at our hobby, or spark an interest in space or communications in general.

Chertsey Radio Club is proud to be affiliated with the Radio Society of Great Britain, who help support the hobby and ensure we have a place to ask questions, share knowledge and learn about new aspects of the hobby.

Chertsey Radio Club is also proud to be associated with AMSAT-UK, who help track monitor and support all things satellite related and keep the community updated with all the latest operating and technical data on the satellites.

Firstly, on 5th July, The ISS crew were instructed to test out 2 cube satellites, Tanusha-1 and Tanusha-2, before deployment. The Tanyusha-YuZGU 1 and 2 (also TanyushaSWSU 1 and 2 or Tanyusha 1 and 2), also known as Radioskaf RS-6 and 7, are two small Russian experimental satellites, which are to be deployed from the ISS during a spacewalk. They were developed at the Southwestern State University (SWSU, YuZGU), Kursk The satellites will broadcast greetings messages in Russian, English, Spanish and Chinese. The test was to ensure the Satellites would both transmit their messages, so using the ISS onboard Amateur radio equipment, relay the messages from the satellite out on 144.800Mhz FM. Amateur radio operators around the world were given an opportunity to hear the messages and I could receive them on my radio set at home.

Part 2
On Saturday 8th July, being experimenters in radio communications, we were very lucky to be able to send voice communications via the International space station, whilst the satellites were being swapped over. The uplink was on 437.050Mhz (output of the Satellite) and downlink on 145.800Mhz I was very lucky to make an initial contact with another Amateur radio station in Spain EA4SG. On the second pass a few hours later, I could talk to Amateur radio operators in Spain, France and I also spoke to my friend in the UK Abdel (M0NPT) which was an exciting and amazingly rare opportunity.

Part 3 
On the last weekend Amateur Radio on the International Space Station (ARISS) celebrated its 20th anniversary – 20 years on both Mir Space Station and on the ISS. 
This organization helps to run and maintain amateur radio on the space station, and set up and run the contacts with many schools around the world including Tim Peake’s Principia mission when he spoke to 10 UK schools last year. 
As part of the celebrations the ISS sent a set of 12 images using slow scan television (SSTV), which when heard on the radio sounds like the old fax noises. 
We were able to receive the sounds and convert them into images when the ISS was in range. 

People all around the globe used simple receivers along with mobile phones, raspberry pi’s, computers and tablets to decode the images. 

I was able to get all 12 of the images at home and some of them are displayed here. the full set can be seen here: http://chertseyradioclub. 
 I recorded a couple of the passes, so you can see how this works, but the earliest in the UK was 23:23 and transmitted through into the early hours of the morning, so we left the decoder running and went to bed. 

Best regards, James Preece (M0JFP) Chertsey Radio Club (MX0MXO) 

RADCOM Publishes Chertsey Radio Club projects

GB8SSD special event Call sign
33 Years since launch of Space Shuttle Discovery

Follow this LINK for more information

Project Thomas Watch

Follow this LINK for more information

Chertsey Radio Club in Practical Wireless magazine for November

Project Thomas Watch

Follow this LINK for more information

Diplexer Virtual Buildathon

Follow this LINK for more information

Retevis RT-82 dual band DMR handie talkie review in Practical Wireless

Friday, 27 October 2017

Retevis RT90 Dual Band DMR / Analogue mobile

Retevis RT90

Dual Band DMR / Analogue radio
Image result for rt90 retevis

I was kindly sent this radio by Retevis to test out and review, I have found the radio very easy to program, the USB cable / com port is detected in the software automatically.

The code plug is available from your local radio dealer and is compatible with the hand held model

Once programmed up using the radio is simple, select the zone (repeater) which is close to you, using the tuning knob on the right side select the talk group.

Use the microphone as usual.

Having the 45 Watts really helps over the hand held and signal reports and access to distant DMR and analogue repeaters was an added bonus.

Powering on and off with Custom screen

You switch on and off the radio using the Green power button and pressing for a few seconds.
You can customise the screen welcome text in the programming software

Showing the Channel selection on DMR and Analogue

Tuning the talk group is simple using the knob on the right side of the radio, you could also use the arrow buttons on the microphone (when mobile this is useful)
To switch into analogue, press the band / esc key, you will have needed to program in analogue repeaters in the same zone to make this work.

Contacts, so many contacts available for use
See a callsign and a name (not just an ID number)

The RT90 has a lot of memory space, this allows you to store a lot of contact details, you can get the list off the Internet and this converts the DMR ID number to a name and Call sign.
A note that the display is bright and stay's lit for about 30 seconds, the microphone also lights up which is useful. 

Changing zone (Repeater)

Changing location, will probably mean you will need to change to a different repeater, or changing different repeater types (analogue, phoenix / Brandmaster) this is easily achieved by using the menu zone option. Zones have an A and B side, A is for digital and B can be used for analogue.

Sending a text message

You have the ability to send and receive text messages on the radio as well, luckily the microphone have an alpha numeric keypad which makes it easy to do.

Programming from the menu / microphone

Instead of having to remove the radio from your car and using the programming cable, which as we know can be a pain, there is the added functionality to program a new zone (repeater) frequency, colour code, time slot(s) and everything you need plus store it in memory. Both for DMR and analogue.

Quick QSO on DMR with David MI6DVM

Here is a quick demonstration of a conversation with David MI6DVM, showing the quality of the digital audio. Its very clear and his report back suggest we are also sounding good to him.

Recorded QSO demo

Given the huge amount of memory in this radio, it has the ability to record both sides of the qso.
You can set this to on by pressing the small red button and off again.
The logs / record is where you can play back the files. It seems to record in and out as separate files.