Saturday, May 18, 2024

New Amateur Radio Repeater Technology in the Southern Cape

New amateur radio repeater technology soon to be installed in the Southern Cape on the "Aasvoëlkop" Repeater Site. 

There is great excitement amongst the users of the 145.750 Mhz "Aasvoëlkop" Repeater.

What is the hype about this new repeater? I will try to explain.  The new repeater has arrived and was recently programmed by Rassie ZS1RP and Dolf ZS1DRP.  The repeater is currently with Johann ZS1AAC who is tending to the duplexer and other equipment needed to bring this repeater to life. The repeater will soon be installed at the 145.625 Mhz Repeater Site in Still Bay.  Once all parameters is confirmed it will be moved to the 145.750 Mhz "Aasvoëlkop" Repeater Site.

A big word of thanks to Johann ZS1AAC, Dolf ZS1DRP and Rassie ZS1RP who is instrumental in the purchase and setting up/programming of this repeater to the benefit of all radio amateurs. As mentioned before this is only the beginning.  There will be more repeater installations and future upgrades in the Southern Cape.  Watch this space!!  I will keep you posted in this regard.

Now we still do not know what repeater you are talking about.  Let's have a closer look.  Here is two photos of the brand spanking new repeater on the test bench.



It is the Yaesu DR-2X 50W Digital Repeater (C4FM IP Interconnect Dual Band Receiver System Multi-function Repeater)


Now lets look at the specifications and other interesting information:

YAESU DR-2X supports C4FM digital / regular FM dual mode and dual receive function relay platform, which includes VHF and UHF amateur radio band. Through the AMS function, the DR-2X mixes communication using conventional FM mode communication and C4FM digital mode.

1. C4FM digital mode provides perfect audio quality
Compared with other digital models, the C4FM modulation mode has better bit error rate (BER) characteristics to ensure good speech quality in communication. The C4FM digital high definition voice technology using 12.5kHz bandwidth enables the high quality voice communication to be transmitted perfectly.


2. AMS makes conventional FM and digital FM friendly co-exist (automatic mode selection).
System integration enables all users, including users using different modes, to communicate with each other. AMS makes all systems possible. AMS automatically identifies C4FM digital signals or regular FM signals, and then DR-2X transforms the identified signals into the current communication mode.

3. Flexible double receiver function
The unique real-time double receiver relay – DR-2X can assign an additional control relay to the relay administrator, transmit an emergency signal, or specify second uplink frequencies. Relay administrators can also independently allocate downlink frequencies based on uplink frequencies.


4. Enhanced Digital Group ID Function
The revolutionary digital group ID function enables users who share the same digital group identification code to quickly and quickly track multiple communication resources and display group member signal strength and telemetry information.
DG-ID
A group ID (0-99) can specify members to participate in group communication. In addition, multi-point relay transmission can be controlled by DG-ID.
DP-ID
For safe relay station operation, you can register the sole ID of the relay station for personal operation identification. DP-ID can restrict access to the relay station members of registered ID.

5. Based on Internet connection relay link system (IMRS), large area expands signal coverage (option).
The Internet link Relay link system (IMRS) allows relay use to connect multiple relays via LAN or WAN. Based on the inherent stability defects of WAN connection, such as the Internet, or the words happen all happened, the new DR-2X mixed a variety of forms of network environment, making the connection between the relay more direct, ensuring the quality of digital communication. Digital group identifier can be used to control relay activation. * required component LAN unit (LAN-01A)


6.
Friendly interactive settings interface 3.5 inch full touch screen

7. Advanced operation
The rear panel controls the I/O port and can be connected to the S-COM7330 relay controller. Up to 3 DR-2X units can be connected to provide programmable sound, clock, access modes and other functions.
8. Other functions
Built-in AC power supply (North American and Asian versions)
Digital squelch code (DSQ) signaling
19-inch standard cabinet connection
CTCSS and DCS sub audio
High stability +-2.5ppmTCXO
Overtime Interdiction Function (TOT)
Firmware upgrade
9. Supplied accessories
AC power cord
DC power cord with fuse
Spare fuse (5A/15A)
Plastic foot
PC Cable SC-20
Operation Manual
Warranty Card

The Yaesu DR-2X is a full feature, heavy duty, C4FM/FM dual band repeater/base station. And unlike many other repeaters, the DR-2X handles conventional FM and C4FM digital transmission. The Yaesu System Fusion technology features the AMS – Automatic Mode Select function that instantly recognizes whether the signal is C4FM digital or conventional FM and automatically switches to match the received mode. The front panel features a full color 3.5 inch, high luminescence TFT touch screen display. The rear panel has both AC input and backup DC input. The power input is auto-switched to backup DC input during power outages.

System Fusion Key Features:
– AMS (Automatic Mode Select) function automatically recognizes the signal as C4FM digital or conventional FM
– Better BER (Bit Error Rate) characteristics of C4FM provides Superior Audio Quality and Crisp Clear Voice
– Better BER (Bit Error Rate) characteristics of C4FM provides better reception while moving and challenging weak signal
– Full 12.5 kHz bandwidth system provides high-speed data communication
– Snapshot Function allows you to enjoy image data with time and GPS information
– Digital Group Monitor (GM) Function
– Smart Navigation Function

Radio Features:
– Modulation Modes: 12.5 kHz C4FM Digital, Conventional FM
– AMS (Automatic Mode Select) function automatically recognizes the signal as C4FM digital or conventional FM
– 3.5-inch Full Color Touch Panel Operation
– Extremely reliable, high RF Output Power: 50/20/5 Watts
– Emergency Operation: Supports auto-switched backup battery power operation
– Front panel microphone connector is provided for use in repeater transmitter testing, and enables use as a base station
– Built-in large-size monitor speaker with front panel volume control
– Internal AC power supply
– 19″ Rack Mount Available
– High Stability ±2.5 ppm TCXO included
– DSQ (Digital Squelch Code) Signaling feature
– CTCSS and DCS Signaling feature
– ID announcement feature (Voice Mode: Requires FVS-2)
– Rear panel Control I/O port is connectable with the “S-COM 7330” repeater controller
– Base Station Operation – Adjustable Squelch Hysteresis (requires a stronger signal to open the squelch than it does to keep it open).
– Adjustable Squelch Tail
– CWID/Voice announcements with stripped PL Tones

DR-2X Exclusive Features::
 -  Dual Receive Operation
 -  Improved News Station feature permits sharing the voice and text messages to members.
 -  Group Monitor feature supports easy Grouping Set-up
 -  Stable High Power Output with large heat sink
 -  Commercial grade components for long-term reliable operation
 -  IMRS (Internet-linked Multi-site Repeater System) function for simple expanded area coverage via the Internet (option).

Specifications:
RX/TX Frequency Ranges: 144 to 148 MHz, 430 to 450 MHz
Channel Steps: 5/6.25 kHz
Circuit Type: Double conversion superheterodyne
Modulation Type: F1D, F2D, F3E, F7W
Power Output: 50/20/5 Watts
Case Size (W x H x D): 19″ x 3.5″ x 15″ (482x88x380mm) excluding knobs and connectors
Weight (approx.): 22.05 lbs. (10 kg)


Final Remarks:

I did some research and played around with various digital radio communication "nodes" in the past.  I would like to share my opinion on a few aspects:

1. This repeater is multi-purpose. VHF/UHF, FM Analog or C4FM Yaesu System Fusion (YSF) and
lends itself to having many more communication choices. Something that is very beneficial these days in Amateur Radio. The audio compared to FM Analogue is excellent as is the Digital Audio C4FM.

2. The repeater function IMRS Lan Module, allows 99 other repeaters to be connected via IP Linking through the Internet.
 
3. Another function is that the repeater can distinguish which mode is used and then automatically switch between the modes. This makes the repeater compatible with traditional FM mode radios and
repeaters.

4. In C4FM mode, call signs and GPS location information can be included in the digital speech
data, which is displayed on digital radios. The following information is displayed: Call sign,
Distance and Direction to the other station. Even small photos can be sent to other stations.

5. Yaesu is the sole manufacturer of YSF equipped radios. The current Yaesu radios are: FT-
1XDR, FT-2DR, and FT-5DR for hand radios, with the FTM-3200R, FTM-100R, FTM-300, FTM-
400R and FTM500DR for mobile units.
 
6. I hear radio amateurs murmuring that they will now have to buy new radios to be able to use YSF.
No, not at all. There are always alternative ways. If you already have a Hotspot then use Pi-
Star's ability to connect to YSF. You can then use DroidStar or a DMR Radio via a YSF "gateway" or "reflector". The second solution is to create a Bridge between YSF and DMR. The last option enables radio amateurs to communicate with Analogue or Digital using Echolink, AllStar or DMR radios whichever option you choose. No one will be left out in the cold.

7 The IMRS Lan Module is optional but is required if you want to connect other repeaters via IP
Links. It also enables you to connect Echolink / AllStar directly to the repeater site. The connection can be controlled via DTMF or the Internet. In my opinion, the IMRS Lan Board is a good addition to the Yaesu DR-2 X Repeater and I encourage repeater owners to buy it as this is the direction in which the technology and amateur radio networks are moving.

8. Here and there radio amateurs might experience small "hiccups" but this is attributed to failure to read and study manuals. The repeater has a learning curve that one will have to overcome and I am sure there might be a few  bumps along the way.
 
9. Having played around with various digital platforms, I think Yaesu's C4FM (YSF) and DMR
are currently the forerunners in the field of digital technology. In my opinion, C4FM from Yaesu is a short head in front of DMR in terms of audio quality. Even in "Digital Narrow" (DN) mode the
Yaesu audio is more natural than all the current digital platforms.

10. Important: The Yaesu DR-2X repeater does NOT have a "full duty cycle" at 50 watts but does
at 25 watts. Something to take note of,  but 25 watts is more than adequate power output vs the location of the Aasvoelkop Repeater.

The Yaesu DR-2X repeater receives an average of 4.7 out of 5 for operation and reliability from radio amateur ranks. The rating says something about this repeater, doesn't it?

I am looking forward to utilize the new Yaesu DR-2X Repeater soon to be installed on the "Aasvoëlkop" Repeater Site!!


End.

Friday, May 17, 2024

Maintenance: Amateur Radio Mast at the Coast

 


Over a period of time I noticed that one of my radio masts (Ex Wind Turbine Mast) was showing signs of rust where two pipes were welded together.  Both the pipes, one 100 mm and the other 38 mm are fully galvanized except where I welded the two together about 15 years ago.  Unfortunately I did not take a photo of the rusted area where I welded the two pipes, before starting the maintenance.  

Now why on earth would I compile this posting of the maintenance. Let me explain.  15 years ago I painted the welded areas with the following coatings after cleaning the areas thoroughly:

1.   Liquid Thinners after grinding and sanding the welded area.

2.  NS 1 Rust Buster ("White Milk" Rust Converter and Primer)

3.  NS 5 Metcote Etch Primer ("Rooi Lood")

4.  Silver Aluminum Paint (2 coats)

5.  Transparent Rust Protector Spray

With all the above layers of protection the rusting process was slowed down for at least 15 years.  After taking off most of the rusted flakes I was quite surprised to find that the rust was not so severe and that the area should last another 15 years after painting the area again with the above products.

I had another trick up my sleeve to further protect and hopefully curb maintenance for the next 18 years.  I decided to put a cover over the welded area preventing rain and sea spray from directly making contact with the metal surface areas that's not galvanized.  In the olden days a VW Beatle rubber drive shaft boot did the trick but unfortunately did not last long as the sun caused the boot to perish after a few years.

I used a PETG UV protected bottle and made a cover hat.  Ordinary 2 liter PETG bottles last fairly long in direct sunlight.  Time will tell how long this protective cover hat will last and if it would protect the welded area better.  Galvanizing the welded area is really not an option as you must arrange transport to George and you pay per kilogram for galvanizing.  Both pipes and the welded area must be hot-dipped.  At R32.00 per kg this would cost more that the two pipes.  Cold galvanizing was another option but at R847.00 a liter and the fact that it dries up in the tin quite quickly, did not make it a viable option.

I could have used my hot air gun to shrink the PETG cover hat tight against the two poles but I was afraid that dampness might be trapped between the pipe and cover due to condensation./dew.  I decided to leave it open at the bottom.  See images.

Finally:  I repainted both poles with Silver Aluminum Paint as I did before and hopefully it will last for the next 15 - 18 years.  It is important at the sea to maintain radio masts and galvanized towers on a yearly basis.  Galvanizing also needs maintenance especially moving parts.  Transparent Rust Protector Spray is used for this purpose.  I trust that this article will be of benefit to those who is not familiar with rust and maintenance of a mast/pole/tower erected in a coastal area.

Images:  Click on images for larger view.













Thursday, May 16, 2024

ZS5SAM - DMR Configuration Tutorial – TAIT EUD (Doc Ver 1.0.1)

Article can be downloaded in PDF format by clicking HERE.

ZS5SAM - DMR Configuration Tutorial – TAIT EUD (Doc Ver 1.0.1)

This document will assist you in setting up a Tait based MMDVM repeater using the TM81xx series mobiles or TB7100 or TB8100 analogue repeater. I configured for the SP8NTH modem board.

I found that DMRDelay setting had to be adjusted from 30 to 45 after last software update so keep that in mind should you experience any RX decoding problems.

Preparing you Arduino Due & and uploading Modem Software

Download and install Arduino software – http://www.arduino.cc

Make mod changes ………..

Download .zip of latest MMDVM Modem Library - https://github.com/g4klx/MMDVM

Create folder called MMDVM in your Arduino Library folder on your PC and extract contents of .zip file into MMDVM folder.

Double click on the MMDVM.ino file which will launch the Arduino application.

Click on the Config.h tab and uncomment :

// #define ARDUINO_DUE_NTH as well as // #define EXTERNAL_OSC 12000000, when using the NTH board with 12MHz external oscillator. Uncomment means removing the two “//” from both the relevant lines.

Ensure that // #define ARDUINO_DUE_ZUM_V10 has the // lines as is uncommented by default.

Latest version of Config.h files also sets parameters for wide C4FSK & RSSI.

Remember to read the BUILD.txt file and follow instructions before compiling your Arduino.

Note:  Click on images for larger view.


Next click on Verify (Tick icon top left above tabs) to check and compile your sketch.

Once you see the “Done compiling” notification click on Upload (Right Arrow Icon) which will again compile your sketch and upload it to your Arduino Due.

If you get an error “unable to find Com Port” check under Tools/Serial Ports and ensure correct Com port was selected then try and upload again.

On completion you will get verification that upload was checked and successful.

Installing OS onto Raspberry Pi (Using Windows OS)

Format 8 GB or larger MicroSD as FAT32

Download latest Raspbian Lite zip file from https://www.raspberrypi.org/downloads/raspbian/

At time of document, Raspbian Jessie Lite was the latest version.

You can also access the online installation guide for multiple OS platforms here, https://www.raspberrypi.org/documentation/installation/installing-images/README.md

Extract the .img file, from the .zip file, into a folder on your hard drive

Launch Win32DiskImager software (as Administrtor), select Image file location as well as MicroSD Device location and write the image file to your MicroSD by clicking on the “Write” button.


On completion of the write you should get a “Write Successful” window. Click OK then eject your MicroSD device and insert the card into your Raspberry Pi, connect via LAN to your network and power up the device.

Raspberry Pi SSH Login without Monitor

Update: New builds of Raspbian now have SSH port 22 disabled by default, therefore you will have to enable it first by attaching a monitor and keyboard and running # sudo raspi-config

All you need connected to your Raspberry Pi is power and LAN connection.

DHCP is activated by default on the Raspberry Pi, thus you will be allocated an IP address by your router.

However keep in mind that the next time you power it up, the router may allocate a different IP address. Next we will scan the network to find the IP address of the Raspberry Pi

We can find out the IP address of the Raspberry Pi by logging into the router and seeing what devices are connected. However an easier way would be to use a tool such as Soft Perfect Network Scanner.


To connect via SSH, download the free program called putty. http://www.putty.org/

Launch putty and enter your IP address from the scanner. Putty defaults to using SSH so no other changes should be required.

You can save the setting for future use, however remember your IP address may change.

 

 

Click on Open. The first time you conect to the Raspberry Pi you will see a warning dialog. This is putty's way of making sure you trust the device you are connectiong to. Click on Yes and the settings will be saved for next time.


You should now have a terminal screen, and can log in using the default username of pi and password, raspberry.



Installing Host Software on Raspberry Pi with Raspbian Jessie Lite

Expand File System and Change Locale

# sudo raspi-config

Highlight option 1 (Expand File System) and tab to <Select> then Enter.

Next highlight Internationalisation Options and set your Locale details

On completion tab to <Finish> then press Enter.

Update/Upgrade OS and install the git application.

# sudo apt-get update

# sudo apt-get upgrade

# sudo apt-get clean

# sudo apt-get install git screen

# cd /opt

# sudo git clone https://github.com/g4klx/MMDVMHost.git

# sudo git clone https://github.com/g4klx/MMDVMCal.git

Build MMDVM Host Software

# cd /opt/MMDVMHost

# sudo make

# sudo nano MMDVM.ini

Here you can customize the ini file to your needs

Build MMDVM Calibration Tool

# cd /opt/MMDVMCal

# sudo make

Turn off Bluetooth on the Raspberry Pi3

The onboard Bluetooth clashes with the Modem and needs to be deactivated with the following command:

sudo bash -c 'echo "dtoverlay=pi3-disable-bt" >> /boot/config.txt'

This adds the dtoverlay=pi3-disable-bt to the bottom of the /boot/config.txt file.

You could alternately manually add this line to config.txt if you wish. Would be good idea to prepend the line with a comment e.g. # Mod to turn off Bluetooth.

Create Service (The text in red needs to be added and saved to file)

# sudo nano /lib/systemd/system/mmdvmhost.service

[Unit]

Description=MMDVM Host Service

After=syslog.target network.target

[Service]

User=root

WorkingDirectory=/opt/MMDVMHost

ExecStart=/usr/bin/screen -S MMDVMHost -D –m /opt/MMDVMHost/MMDVMHost /opt/MMDVMHost/MMDVM.ini

ExecStop=/usr/bin/screen -S MMDVMHost -X quit

[Install]

WantedBy=multi-user.target

# sudo chmod 755 /lib/systemd/system/mmdvmhost.service

Create a symbolic link between your script and a special location under /etc:

# sudo ln -s /lib/systemd/system/mmdvmhost.service /etc/systemd/system/mmdvmhost.service

Create Timer (The text in red needs to be added and saved to file)

# sudo nano /lib/systemd/system/mmdvmhost.timer

[Timer]

OnStartupSec=60

[Install]

WantedBy=multi-user.target

# sudo chmod 755 /lib/systemd/system/mmdvmhost.timer

Create a symbolic link between your script and a special location under /etc:

# sudo ln -s /lib/systemd/system/mmdvmhost.timer /etc/systemd/system/mmdvmhost.timer

Make systemd aware of your new service (This enables new service and activates the 60 sec timer)

# sudo systemctl daemon-reload

# sudo systemctl enable mmdvmhost.timer

# sudo reboot

Service should start 60 sec after bootup.

Some more usefull commands

Start Service manually

# sudo systemctl start mmdvmhost.service

Stop Service manually

# sudo systemctl start mmdvmhost.service

Restart Service manually

# sudo systemctl start mmdvmhost.service

Connect to Screen Output

# sudo screen -r MMDVMHost

Ctrl+a then d to disconnect from screen and keep the service running.

Run MMDVMHost

# sudo ./MMDVMHost MMDVM.ini

Run MMDVMCal

# sudo ./MMDVMCal /dev/ttyACM0

To update MMDVM App

# cd /opt/MMDVMHost

# sudo mv MMDVM.ini /opt/MMDVM.ini (move existing MMDVM.ini file to safe place)

# sudo git pull https://github.com/g4klx/MMDVMHost.git

# sudo make

To update CALIBRATE app follow above but of course be in the MMDVMCal directory and also point to MMDVMCal.git at repository.

Notes:

It is recommended supplying the Due with 5VDC at the micro USB socket. (2B recommend 1.2A and Model 3 recommend 2.5A)

Raspberry Pi – Commands

sudo apt-get update

sudo apt-get upgrade

sudo apt-get clean (Cleans out update Cache)

sudo rpi-update (Updates Pi Firmware)

Calibrating your Modem

TX Calibration

For TX Calibration, use a spectrum analyzer to observe the TX RF directly.

Launch the MMDVCal program (# sudo ./MMDVMCal / dev/ttyACM0) and select the DMR test 1.2kHz test tone.

Use MMDVMCal to switch the repeater to TX and generate the DMR Cal signal. (Space bar switches TX on/off)

While slowly turning the TX deviation pot on the Modem board observe the sidebands of the RF signal on the analyzer. When you have reached the correct deviation level, you will notice that the carrier in the center of the RF spectrum shows a clearly visible dip. This is the "Bessel zero" where the deviation of both tone sidebands "zero out" the carrier. Adjust the pot for maximum dip depth.

I found this null point to equate to about 2.9kHz Deviation using the MMDVMCal 1.2kHz test tone.

RX Calibration

Preset RX audio from receiver to -10dB @ 1kHz (1.5kHz wide) at the Modem header (SV2)

Next use an oscilloscope to check the incoming RX signal from the Modem board to the ADC pin (Pin A0) of the Arduino Due:

The Modem board should create a 1,65V DC offset (Half 3.3V) at the ADC input. Key your radio on a simplex channel and observe the audio on the ADC pin overlaying the DC offset. You can use the rising edge of the receiver’s RSSI signal for triggering the scope.

The RX pot on the modem board must be adjusted in a way that the peak amplitude of the audio signal neither reaches the zero or the 3.3V maximum. Keep a margin of 0.3 to 0.4V to both limits to be safe! Take care to ensure that the ADC input of the SAM3X is never overdriven by the audio signal. For a fine tuning you can adjust the TX / RX settings in the MMDVM.ini file

It is recommended supplying the Due with 9VDC at the 2.1mm DC socket and not relying on the 5VDC supplied via the USB port (250mA)

Notes when using external 12MHz FCXO

The frequency of the TCXO must be an integer multiple of 24000 and 48000

Frequencies such as 12.0 Mhz (24000 * 500) and 14.4 Mhz ( 24000 *600) are suitable.

Frequencies such as 10.0 Mhz (24000 * 416.666) or 20 Mhz (24000 * 833.333) are not suitable.

This can be configured in the Config.h file prior to the code being compiled and loaded into the Due.

To configure the code for your oscillator uncomment the relevent line in the Config.h file by deleting the // characters.

e.g. #define EXTERNAL_OSC 12500000

Next you need to ensure that the setting OscOffset = in your MMDVM.ini file is set to zero. This setting is only for used when calibrating the internal oscillator and not required when using an external clock. (IC4 is not required so simply jumper R2 & R26 with 0 Ohm resistors instead)

Also keep in mind that the NTH Modem board caters for HCMOS TCXO type and not the Clipped Sinewave type TCXO.

Tait T2000 mods for DMR

Receiver (RX)

Fit a DB9 connector to rear of radio in space provided.

Pins to use

S13-1 DET-AF-OUT to DB9 Pin 6 .166mV (-15.6dB) present

S13-11 OPTIONS GROUND to DB9 Pin 8

S14-3 BUSY to DB9 Pin 9 (BUSY is High + 5VDC in idle)

Transmitter (TX)

S13-11 OPTIONS GROUND to DB9 Pin 8

S14-6 PTT FROM OPTO to DB9 Pin 9 (Is High +5VDC in idle)

S13-8 TX-SIG-IN to DB9 Pin 6 .675mV (-3.5dB) present – Use 2.2uF Cap

The T2000 is not the ideal radio to use for DMR as frequency drift causes problems. Radio needs to be on for close on an hour before VFO is stable enough for DMR.

Tait TM8115 & TM8200 mods for DMR

Receiver (RX)

Under Basic Setting – Change Squelch Detect type to “Signal Strength” – This is NB!

Go to Programmable I/O – Digital Tab and change as follows:

Next go to Programmable I/O – Audio Tab and change as follows:


Save file and program these changes back to the radio.

Transmitter (TX)

Under PTT – Select the External PTT (1) Tab and change as follows:


Next go to Programmable I/O – Digital Tab and change as follows:

Next navigate to Programmable I/O – Audio Tab and change as follows:

Note: When inputting your frequencies remember to use 12.5kHz spacing

TM8115 Auxiliary Connector

The auxiliary connector is an 18 way two row right angled IDC (Insulated Displacement Connector)

On the Receiver (RX) we will be using the following Pins

Pin 1 AUX GP0I7 BUSY to Modem Pin 5 (Green)

Pin 6 RSSI to Modem Pin 6 (Purple)

Pin 13 AUD TAP OUT RX Aud to Modem Pin 4 (White or Yellow)

Pin 15 AGND Ground to Modem Pin 2 (Black)

On the Transmitter (TX) we will be using the following Pins

Pin 2 AUX GPI05 PTT to Modem Pin 3 (Yellow)

Pin 7 AUD TAP IN TX Aud to Modem Pin 1 (Red)

Pin 15 AGND Ground to Modem Pin 2 (Black)

 


TM8115 Microphone colours


Plug wired as follows, using standard Tait remote extension cable –

Pin 1 Purple, Pin 2 Blue, Pin 3 Green, Pin 4 Yellow

Pin 5 Orange, Pin 6 Red, Pin 7 Brown, Pin 8 Black


Dipole separation Notes - UHF

2m separation = 47dB isolation

4m separation = 59dB isolation

RJ45 – LAN – Wiring


Tait TB7100 Mods for DMR

Interface Board

Ensure the following interface board links are set as follows:

LINK POSITION NAME FUNCTION

J400 1-2 TX Key Source External PTT Signal to Transmitter

J500 1-2 Line Out Freq. Response Flat Response

J501 1-2 Line In Freq. Response Flat Response

J502 1-2 TX Audio Source External audio line to transmitter

J503 2-3 RX Audio destination Received Audio sent to Balanced & Unbalanced outputs

J507 2-3 Line In destination AUDIO_TAP_IN The TX audio tap in point

TB7100 Auxiliary Connector

You can connect your modem to the following pins on the 25 pin D-Range connector.

PIN Name Type MMDVM Position

9 RSSI Output RSSI

11 TX audio Input Input TX

13 Ground Ground Ground

14 RX Gate Output SQL

15 TX Key Input PTT

24 RX audio Output Output RX

Receiver RX

Under Basic Setting – Change Squelch Detect type to “Signal Strength” – This is NB!

Go to Programmable I/O – Digital Tab and change as follows:


Now go to to Programable I/O – Audio Tab and change as follows:

Save the file and also program the changes to the RX side of the repeater

Transmitter (TX)

Under PTT – Select the External PTT (1) Tab and change as follows:


Next go to Programmable I/O – Digital Tab and change as follows:

Next navigate to Programmable I/O – Audio Tab and change as follows:


Note: When inputting your frequencies remember to use 12.5kHz spacing.

Save the file and also program the changes to the TX side of the repeater.

Tait TB8100 Mods for DMR

Changes to be made to the default settings of the TB8100

Launch the TB8100 Service Kit and navigate to Channel Profile > Receiver Gating and change as follows:

Followed by Channel Profile > Signal Path


Line Level values are selected to give as close to -10dBm in & outputs as possible. In this case 0.7Vpp did the trick.

Next navigate to Signaling Profiles > TX Timers and uncheck the Hand time checkbox.

TB8100 Auxiliary Connector

You can connect your modem to the following pins on the 25 pin D-Range connector.

PIN Name Type MMDVM Position

3 RX audio output Output RX

5 TX audio input Input TX

8 RSSI Output RSSI

9 RX Gate Output SQL

10 TX Key Input PTT

25 Ground Ground Ground

MMDVM.ini file

Lines that need to be edited are highlighted in Yellow – Critical settings are in BOLD

[General]

Callsign=ZS0ABC // Repeater Identifier

Timeout=300 // TX Time out Timer

Duplex=1 // 1 for Duplex – 0 for Simplex

# ModeHang=10

RFModeHang=10

NetModeHang=3

Display=None

Daemon=0

[Info]

RXFrequency=430625000 // RX Frequency of repeater

TXFrequency=438225000 // TX Frequency of repeater

Power=5 // TX Output power

Latitude=-29.550000

Longitude=30.052277

Height=156

Location=Durban

Description=Multi-Mode Repeater

URL=www.dmr-za.net

[Log]

# Logging levels, 0=No logging

DisplayLevel=1

FileLevel=0

FilePath=.

FileRoot=MMDVM

[CW Id]

Enable=1

Time=15

[Modem]

Port=/dev/ttyACM0

# Port=\\.\COM3

TXInvert=1

RXInvert=1

PTTInvert=0

TXDelay=60 //60 Gave best results but alter to your own needs

DMRDelay=45 // 30 works well for TM8115 & TB8100 40 for TB7100

RXLevel=50

TXLevel=90 // 90 worked for me but alter to your own needs

# D-StarTXLevel=50

DMRTXLevel=90 // Set same as TX Level

# YSFTXLevel=50

OscOffset=0

RSSIMultiplier=1

RSSIOffset=0

Debug=0

[D-Star]

Enable=0

Module=C

SelfOnly=0

[DMR]

Enable=1

Beacons=1

Id=6555XX //Your ID Here

ColorCode=1

SelfOnly=0

# Prefixes=234,235

LookupFile=DMRIds.dat

CallHang=3

TXHang=4

#Blacklist=

#DstIdBlackListSlot1RF=

#DstIdBlackListSlot2RF=

#DstIdWhiteListSlot1RF=

#DstIdWhiteListSlot2RF=

#DstIdBlackListSlot1NET=

#DstIdBlackListSlot2NET=

#DstIdWhiteListSlot1NET=

#DstIdWhiteListSlot2NET=

[System Fusion]

Enable=0

[D-Star Network]

Enable=0

GatewayAddress=127.0.0.1

GatewayPort=20010

LocalPort=20011

Debug=0

[DMR Network]

Enable=1

Address=154.66.196.131

Port=62031

# Local=3350

Password=Password Here

RSSI=0

Slot1=1

Slot2=1

Debug=0

[System Fusion Network]

Enable=0

LocalAddress=127.0.0.1

LocalPort=3200

GwyAddress=127.0.0.1

GwyPort=4200

Debug=0

[TFT Serial]

Port=/dev/ttyAMA0

Brightness=50

[HD44780]

Rows=2

Columns=16

# For basic HD44780 displays (4-bit connection)

# rs, strb, d0, d1, d2, d3

Pins=11,10,0,1,2,3

# Device address for I2C

I2CAddress=0x20

# PWM backlight

PWM=0

PWMPin=21

PWMBright=100

PWMDim=16

DisplayClock=1

UTC=0

[Nextion]

Port=/dev/ttyAMA0

Brightness=50

 

Wednesday, May 15, 2024

Make your own Balun Enclosure by Christi ZS4CGR

Many of us either buy a fully new constructed/manufactured balun while others build their own and install them in a plastic box. Christi however decided to roll his own enclosure for his baluns.  Thank you Christi for sharing your homebrew "Patent".




Construction is quite simple.  PVC Pipe, End Caps, Electric Fence Insulator, Bolts/Nuts and Softened Stainless Steel Wire. 

New Amateur Radio Repeater Technology in the Southern Cape

New amateur radio repeater technology soon to be installed in the Southern Cape on the "Aasvoëlkop" Repeater Site.  There is great...