08 September 2022
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5
minutes read
We were recently asked if we could help with the setup of a local AllStar Link radio repeater for our area.
AllStar Link is a radio repeater system which uses Voice over Internet Protocol to allow distant radio hams/amateurs to communicate via a local access repeater. More details about AllStar Link can be found at https://www.allstarlink.org.
The AllStar Link software runs on a Raspberry Pi or other compatible hardware and uses a modified CM108 USB sound card as an interface to the radio.
A Tait TM8110 PMR Radio was purchased for the repeater from a local ham radio rally.
The Tait TM8110 radios have a 6-pin RJ45 connector on the front panel for the microphone and an auxiliary connector on the rear panel using a 15-pin D-Sub connector.
Programming Cable
There are commercial programming cables available for the Tait radios but the only models we could find were in America and had expensive shipping charges.
The radio uses a UART connection at 3.3V for programming and we initially tried to connect the radio to the computer using our USB MultiComms interface via the front RJ45 connector.
We were unable to get any response from the radio and after further investigation, we found that the Tait radios use an inverted UART signal.
After adding a logic inverter via a breadboard, we were able to communicate with the radio and the programming software.
Making a USB Programming Adapter
Once we knew that we could program the radio, Andrew designed a very compact USB to Serial interface with logic inverters and ordered the PCBs. After a couple of weeks, the new boards arrived, and the components were soldered to the board.
The interface uses an FTDI FT230X chip and a pair of SN74LVC1G04DBVR inverter chips to invert the output to the 3.3V logic the radio requires.
Bill of Materials
| Name / Part No | Value / Description | Quantity | RefDes |
|---|---|---|---|
| CAP_0603 | 47pF | 6 | C1, C2, C3, C4, C5, C6 |
| TX | Red LED | 1 | D1 |
| RX | Red LED | 1 | D2 |
| 48037-0001 | Molex USB Connector | 1 | J1 |
| MI0805K601R-10 | FERRITE BEAD 600 OHM 0805 1LN | 1 | L1 |
| RES_0603 | 27R | 4 | R1, R2, R5, R6 |
| SN74LVC1G04DBVR | Texas Instruments Inverter | 2 | U1, U3 |
| FT230X | FTDI USB Full Speed to Basic UART IC | 1 | U2 |
The PCB and schematic can be downloaded in Diptrace format from github.com/briandorey/USB-Programming-Cable-for-Tait-TM8110-PMR-Radios
The pinout for the RJ45 connector is:
| Pin | Signal name | Description | Signal Type |
|---|---|---|---|
| 1 | PRG_RX_AUD | Receive audio output | Analog |
| 2 | +13V8 | Power supply output. Switched off when radio body is switched off. | Power |
| 3 | PRG_TXD | Asynchronous serial port - Transmit data. | 3.3V CMOS |
| 4 | PRG_PTT | PTT input from microphone. Also carries hookswitch signal. | Digital |
| 5 | PRG_MIC_AUD | Fist microphone audio input. | Analog |
| 6 | AGND | Analog ground | Ground |
| 7 | PRG_RXD | Asynchronous serial port - Receive data. | 3.3V CMOS |
| 8 | PRG_ON_OFF | Hardware power on/software-power off input. Active low. | Digital |
Links
USB Sound Card: www.amazon.co.uk
USB Sound Card Modifications: allstarsetup.com/how-to-modify-a-cm108-for-allstar/
Tait TM8100 Series Programming Software: www.radiotronics.co.uk/tait-tm8100-series-programming-software
Hamvoip software: hamvoip.org
Robin
Is there any chance to use PL2303 or CH340 for this schematic?
Brian
Either of these chips should work for the UART communications
Petir
Would you please to tell me the pin of TX and RX in J3?
Brian
Hello Petir
The pins are:
1 - TX
2 - RX
3 - GND
Petir
I'm sorry that I am mistakenly mention in my question before.
What I mean is the position of TX, RX and Ground in RJ45 pin of Tait mic's pinout
Thank you
Brian
Hello Petir
The microphone connector pinout is listed above
Petir
Well
Finally, it works.
Thank you
Mohamed
I need Tait 8100 Software V3.09, Please help me
Petir
Thank you. I can make the cable for tait from pl2303 and ch340 module
Andreas
Can you provide a new link for the programming software?
Brian
The software link is at the end of the post
Pete, GW8UXL
Hi All,
Here is a much simpler method of making a programmer for the Tait T2000 and TM8000 series radio, I wrote an article for this programmer a few years back for a well known ham-radio magazine. Anyway I hope it helps anyone wanting to make their own programming lead, I like to make all of my own.
If you use a 6-Pin plug it will, fit and program both the T2000 and TM8000 radios.
Good luck and have fun guys.
Pete, G8UXL /GW8UXL (QTHR QRZ.com).
For reasons I do not understand I can’t post the article, if any one would like the article please email me, my address is on QRZ.COM
(Mar 24).
Pete, GW8UXL
Hi Again,
Sorry I just re-read the post, properly this time! and realised my programmer may not be relevant for this purpose, sorry about that.
Thought I may be helping the less technically experienced build their own programming lead for the Tait T2000 & TM8000.
Pete. GW8UXL. /G8UXL.
sergio SA
ok
Robert
where can i buy the PCB from please?
Brian
There is a link in the post for the PCB files and you can then order them from any pcb manufacturer