Frequency Expansion: Alinco DJ-MD5TGP

The Alinco DJ-MD5TGP can now easily be expanded to receive up to 520 MHz which is helpful to those that live in areas that use frequencies above 480 MHz such as New York City.

After upgrading the Alinco from FW 1.00 to the not 100% publicly available FW 1.04, I decided to try some key commands that did not work before while trying to reach the same frequency expansion results in the past.

Given that the Anytone AT-D868UV, AT-D878UV and BTECH 6X2 all share certain design elements as the Alinco this not all all too surprising with the latest firmware update rolled out to the Alinco DMR dual band radio.

How To Expand

Step 1: Hold down the 1 key, PTT and the side button directly underneath PTT while turning the radio on will show "DJ-MD5 TEST MODE" quickly followed by the Alinco splash screen.

Step 2: Rotate the multi-selector knob on the top of your radio to the desired operational mode and then turn off the radio.

Step 3: Your radio now will function as the mode you selected.

Using with CPS

If you read the data from your radio using the "Model" function, it should show which of the 14 options available through the test mode with the latest CPS v1.03.

Its now safe to start writing a new code plug or importing channel data again back into your radio.

Please note that you will need to inhibit or enable the transmit function on a per channel basis per your legal requirements.

Enjoy your new "receive" capability if you were looking to access frequencies above 480 MHz with a much smaller DMR capable radio compared to the Anytone or BTECH models.

Looking for interesting discussion about getting the most from digital voice communications?  

Check out www.northstardigitalnet.us for details

MMDVM JumboSPOT board: Mods you may need

This is the JumboSPOT board that was/is sold on ebay and other online places. This board along with a Rasberry Pi Zero and a SD card loaded with PiStar makes up a Digital Radio Hotspot.

Depending on when you purchased your board and for what price, you may need certain modifications. The following mods have ONLY be tested / verified on the above board. As with anything in life, you take on the risk and responsibilities of preforming these mods. If you don't know what you are doing, STOP and don't do it!

Antenna mod

If you installed the SMA connector at P3 and plan to use the included SMA external Antenna you need to remove the cap ( see A in above picture ). This removes the connection to the internal ceramic Antenna ( not shown about ) at AE1. Bottom line is that you should not run two Antenna's so removing C28 makes sure that only Antenna is P3.

Flash FW mod

Most early boards shipped with only the 10 pin connector soldered as in the above picture. This meant that you were unable to flash updates to the STM32A103 microcontroller chip. Thus the two pins in the above picture ( marked B and in the red rectangle ) need to be connected to the Rasberry Pi's GPIO pins 20 and 21 which will be right below them.

It is a direct pass through, NOT a jumper as most people assume. So you just need to add a female header to your JumboSPOT board and a male header to the Raspberry Pi. Current boards place a 10 pin female header on both sides of the JumboSpot, which will work, but only thoes two pins are needed. Once the pins are connected you will be able to use the PiStar Firmware update script to update your JumboSpot to the latest version of HS_HAT which is displayed on the PiStar admin page.

OLED display mod

If you just purchased the JumboSPOT board it most likely did not come with an OLED display. You can add one later on if you like. Just look for " 0.96" I2C IIC SPI Serial 128X64 White OLED LCD LED Display Module for ArduinoG9K " or similar. The display gets connect to the top row in the above picture ( refrence "C" ) and not the bottom row that is marked. The main issue is that the pins must match the board pins which are listed above. From left to right they are [3.3v] [GND] [SCL] [SDA] So since you solder the display so that it's facing out the screen you purchase should match that config like so:

 I was able to find this module for 450% less then the ones listed as compatible to the JumbSPOT so don't get fooled by the seller, you can use compatible modules as long as it has the correct pins and supports "I2C IIC SPI Serial". Also note that the display will NOT turn on unless you have it configured and PiStar attaches to a server on the Internet ( as in Brandmister etc ). In PiStar http://pi-star.local/admin/configure.php make sure you have it configured as in:

Adding Ethernet to your Pi Zero mod

This one requires no-soldering! Just chose the correct part from eBay or your favorite Chinese vendor. The PiStar distribution will support an Ethernet adapter out of the box. It's even smart enough to use Ethernet over WiFi and fall back to WiFi if Ethernet fails. But which one to get. If you search for "MMDVM Hotspot Ethernet Adapter" you will be paying the most you can pay. If you look for "Micro USB 2.0 to Ethernet 10/100 RJ45 Network LAN Adapter" you will find ones EIGHT TIMES less! Make sure that it supports Linux and you will be safe. Also I suggest getting one more then you need. When I ordered three, only two worked. Since I only needed two it was worth buying extra ( these parts are really REALLY cheap and cheaply made ).

 

What do you think?

Please leave constructive comments. If you have mods of your own please share. Like most of you out there I was attracted to this hobby because I could MOD things, make them better! So pitch in and share your knowledge!

TYT MD-380 Charger Modification

Here we have two different modifications to the popular (and highly hackable) Tytera MD-380 DMR/Analog 70CM radio

• Modification of charger to disable "green" led when charger is powered. After modification, charger will only light up "red" during" charging and will be off when charging is complete.
• Addition of a capacitor and RFI bead to cut down radio frequency interference RFI radiated from the charger base when used with a switch mode AC to DC adapter

Here is the charger indicator modification

Here is the RFI suppression modification before and after

The large electrolytic capacitor and inductor were loose on the PCB, I re-soldered them so they sat flush to the PCB which also helped RFI suppression

The charger is supposed to take an input voltage of 12.5V and an output of 8.4V. Measure your AC to DC adapter with a multi meter on both sides. Any output to the charger pins between 7.9 to 8.4V is safe. Any lower or higher will damage your battery and the the total number of charge cycles it can take in its lifetime. If your Ac to DC adapter outputs more than 12.5V, you may want to replace it with a more appropriate one or add a dropping resistor to lower its voltage.

Steve K2GOG