This Wiki entry is based on notes provided by Mason Creager, AF5WN.
Using a DB25 and a mini DIN-6:
Din pin 1 ---> DB25 pin 8 (TX Data)
Din pin 2 ---> DB25 pins 12 & 19 (GND)
Din pin 3 ---> DB25 pin 16 (PTT)
Din pin 4 ---> DB25 pin 10 (RX Data)
If you require further information use the UDRC™ II pinout provided on the NW Digital Radio site and use the TKR-850 manual page 52 (the DB25 pinouts are the same on both the TKR-750 and TKR-850).
Programming the TKR-750/850 Repeater
This part is really simple. Remove all functions for the 6 programmable pins on the DB25, you won't need them for the UDRC. Do not set any encode/decode tones (Note: it may be possible to use tones to have dual mode repeater - K7VE), remove the courtesy tone, remove the CW id, do not use multi table, and do not scan del/add. Set the operation mode to duplex, change the bandwidth to narrowband and finally set your frequency and hang-times as required.
Setup the UDRC™
Follow the Wiki for converted analog repeaters. Setup the UDRC™ for using the mini DIN-6 port:
- serial config 5
- duplex mode 0
- RX Inversion on
- TX Inversion off
If you have any issues Mike Morneau provides a good step by step dstarrepeaterconfig guide, I found it easier to use command line approach.
Adjust your alsamixer Settings
This was the most difficult part of the process but these settings should get you on the right path. I would adjust it using an ID-5100 since the RX is so picky. Load the standard DR-1X script for alsamixer. While dstarrepeater is running open alsamixer and set the PCM level to 0 dB and set the LO drive to 7 dB, save the config and store it. This is what got my specific repeater's audio levels just right, it may not work for you based on any internal or KPG programmed audio levels on the repeater. The best bet would be to set the PCM to 0 dB and adjust the LO level until it makes an ID-5100 happy.
Setup ircddbgateway per the wiki.
Summary by AF5WN
I would highly recommend running ircddbgateway and dstarrepeater as daemons and programming everything via command line. It seems that there were less issues getting everything setup. I believe this is the first successful UDRC interface to a Kenwood TKR-750/850 repeater and the setup should be the same if not very similar to the TKR-751/851 series repeaters as well. When the internet gets setup, feel free to drop on in to the W5STR repeater and try it out. This will be the first wide area D-Star repeater system in Central Arkansas. We will also be participating in a lot of the same nets as the Memphis W4LET group.