About G6NJM - Chris

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DX Commander HF Multi-Band Vertical Antenna

Recently, I’ve been looking at multi-band verticals with a view to portable/holiday, and temporary home use too. I think I found the solution and purchased the DX Commander Premium Build – HF Multi-Band Vertical Antenna System from Callum, M0MCX. I will add further post(s) as I go through building the kit.

I would like to thank Callum (M0MCX) for his prompt and helpful replies to questions leading up to my purchase decision.  Callum hosts a DX Commander YouTube channel with very frequent new videos for the amateur radio community aimed at encouranging experimentation, explaining all things antenna related and much more… you have to check it out.

I watched all the DX Commander contruction videos and highly recommend them if you are considering an HF multi-band vertical antenna.  There are three main parts and other related videos. Use an internet site search with “Building a multi-band Vertical ham radio antenna DX Commander Part 1” and you’re sure to find it.

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Reducing MD-380/RT3 low power level for hotspot use

A battery saving technique that has been posted on the internet, provides instructions for reducing the low power setting on the TYT MD-380 / RETEVIS RT3 to approximately 100mW. Remember it is at your own risk if you try this!
I have modified both my Tytera MD-380 and Retevis RT3 using these instructions on SQ9JDO’s website.

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DVMEGA & BlueStack Boards

DVMEGA & BlueStack-Micro+ Boards

These are the circuit boards that comprise a DVMEGA BlueStack (Android) or iBlueStack (iOS). Either of these BlueStack-Micro+ boards can be paired with either of the DVMEGA radios – the single band or dual band.

These hotspots can operate in two modes:

  • ‘push button out’ for Bluetooth to Android (BlueStack-Micro+) or iOS (new iBlueStack-Micro+) using BlueDV software
  • ‘push button in’ for connection to Raspberry Pi 2/3 or PC using BlueDV, MMDVM, Pi-Star (check availability)

Here is a photo of the dual-band 2m/70cm DVMEGA on BlueStack-Micro+ board connected via cable to USB port on Raspberry Pi 2. This configuration can run BlueDV (Linux), Pi-Star or other MMDVM options.

The software you decide to use will be based on how you prefer to operate in the different modes supported.

With BlueDV software:
Android/Windows PC – DMR/DSTAR/FUSION
iOS – DMR/FUSION (DSTAR not supported due to technical limitations). This version supports background operation for DMR which is an excellent feature.

DVMEGA BlueStack units operating in Bluetooth mode need no computer and run on battery packs for extended periods. Perfect for use with Android and iOS phones/tablets (check versions of phones/tablets for compatibility).

In the UK, these products are available from Karl Powell and now also ML&S. In the Netherlands, from Combitronics.

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Pi-Star for Raspberry Pi

Wanting to try out MMDVM on the Pi, I came across a distribution called Pi-Star that is excellent and extremely simple to set up. Brilliant work by Andy Taylor, with responsive Facebook support group.

Have used with a Pi2 and Pi3 in combination with DVMega BlueStack connected via USB for several weeks now.

I have added a Nextion 2.4″ screen that I purchased a while ago but was still sat in its box. Using these instructions, I was up and running displaying modes and callsigns in less than 30 minutes! It connects via the Pi2/Pi3 IO pins. Brilliant.

Update: Pi-Star supports DVMega boards plugged onto Pi2/Pi3 IO pins OR via a BlueStack configuration. If using the DVMega board on the Pi, the Nextion screen will need to connect via USB using this USB 2.0 to TTL Module Serial Converter adapter. If using USB to connect the screen, follow the same instructions above but replace /dev/ttyAMA0 with /dev/ttyUSB0 in the Nextion Port setting of the initialisation file.

Note: The Nextion 2.4″ screen is now available (since July 2017) in the UK from ML&S.

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FullSizeRender

Latest Pixel image with 3.5″ screen

The DV4Mini now working extremely well with firmware 1.77.

Created a new build for the Raspberry Pi2 consisting of:
Take either of the latest Pixel images for DV4Mini from:
EA7IYR: http://dv4.es/index.php/2017/03/05/dv4mini-pixel-img-raspberry/
K2DLS: http://www.k2dls.net/blog/2017/03/12/new-raspberry-pi-23-dv4mini-image/

Thanks to EA7IYR and K2DLS for making these images available.

Add the BM XTG from http://www.k2dls.net/blog/2017/04/20/bmxtg-1-2-released/ if not using the K2DLS image.

This system uses the Waveshare/Makibes 320×480 LCD screen:
http://www.waveshare.com/3.5inch-rpi-lcd-a.htm
originally purchased from Amazon https://www.amazon.co.uk/Makibes-Screen-320×480-Designed-Raspberry/dp/B00UV78E9Q/
For Waveshare 3.5″ screen support, I used LCD-show-170309.tar.gz from http://www.waveshare.com/wiki/3.5inch_RPi_LCD_(A).

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Connect Systems CS750 DMR Handheld

I’ve had the opportunity to visit Connect Systems, Inc. (in Agoura Hills, CA 91301) a couple of times over the last 12 months and found them to be extremely helpful and knowledgable about their Amateur Radio DMR radios.

I visited this week to catch up on the latest information on their new CS580 and CS760. I ended up with the purchase of a Connect Systems CS750 DMR handheld.

On first impressions, there is a lot to like about the CS750, the build quality, the backlit display and keyboard, front panel programming and the entire contact database in the radio. More feedback once I’ve had hands-on experience with the radio.

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Hotspots for DMR, Fusion and DSTAR

I really enjoy these modes via the hotspot and having owned the DV4mini for a year, wanted one that was even more portable so recently purchased a dual band DVMEGA and BlueStack Micro+ combination in a 3D printed custom case. This primarily uses the BlueDV Android or Windows software. Coincidentally I also had a SharkRF OpenSpot on backorder which has now turned up so I will be comparing all three units in the different modes over the coming months. The interface to the OpenSpot is any web browser.

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Tytera TYT MD-380 DMR Handheld

I’ve had the Tytera TYT MD-380 DMR Handheld now since last Christmas and now it has the experimental firmware and I update it regularly with the DMR ID database using WH6AV script on the Raspberry Pi, so that names and locations are shown on screen for all operators. This is a really convenient feature. The radio has been excellent, no problems with it or batteries.

Most of the radio use is with internet connected hotspots rather than repeaters. There are two DMR repeaters within 10 miles but I can’t access either from the home QTH. So thats why I first purchased the DV4mini.

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12 months on with he DV4mini

Is it already 12 months since purchasing a DV4mini and experimenting with DMR, Fusion and DSTAR.

My DV4mini is now runnning firmware 1.73 and the latest Raspberry Pi version released on 21 November 2016 by Wireless Holdings. I have not experienced the problems some have done with this product, although this latest firmware and software is the best yet. I mainly used this software, but on my compact setup still use the DV4mini-Compact software.

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DV4mini-LCD-Keyboard

DV4mini latest setup

Some people are looking for a convenient setup for their DV4mini – this is mine – and is extremely reliable and portable.

  • Raspberry Pi 2 Model B Desktop (Quad Core CPU 900 MHz, 1 GB RAM, Linux)
  • Edimax EW-7811UN 150Mbps Wireless Nano USB Adapter
  • Rii i8+ 2.4GHz Mini Mobile Wireless Keyboard with Touchpad Mouse, Backlit LED, Rechargeable Li-ion Battery and Silicone Cover
  • LCD 480 x 320 screen (optional) or external HDMI connected screen (optional)

I use an operating system build with VNC server enabled, then I can connect from my iPhone, iPad, using VNC Viewer by RealVNC (or other VNC viewer apps).

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