On 1/7/19 9:39 PM, Bryan D. Boyle wrote:
DMs are stupid simple to connect to a URI. Just need discriminator rx audio, ground, xmit flat audio, and ptt. IIRC, rear connector pins 3, 5, 7, 11 (check the multitude of online sites for the specifics, but this is what I recall)
set up radio in CPS to send the right signals to the right pins, turn off pre/deemphasis in radio, do all the rest (COS, pl decode/encode, de/preemphasis, etc) in asterisk.
I have some example codeplugs for transmit and receive radios. I built a test node a couple months back for dev use and used CDMs. I will put them up on the wiki <https://wiki.allstarlink.org> once I get the uploader working for cpg files. Some pics of the repeater: https://imgur.com/a/NXIlQ45 Note, I put in two DE-9's for connecting to the audio interface, one is simple usb, the other is usbradio. I did run into one issue on the CDM, as the transmit CDM was a UHF 2 that I brought down to cover 440-517 MHz (from 450-527). The deviation response vs modulation frequency (modulation balance) was way off, even after aligning to the Motorola standard. What I found was motorola says to use a 80 Hz and a 3000 Hz at the same level to align the balance in tuner. The issue is by 3000 Hz the radio is already rolling off, and this distorts the modulation balance. The solution i found was to align it using 80 and 2500 Hz. This makes the radio look like a known good radio. Made a little graph of it here if anyone is interested.
https://docs.google.com/spreadsheets/d/17_wWe14px_-2LUHl6XJN6EMRTjYnuYQXnqUB...
Again, OT here and likely not applicable unless you're needing to completely re-align the radio due to moving the frequency.
Take longer to wire the cable up than to get the sw working, in my experience.
Verification of perfection is what takes the longest. 73's -- Bryan Fields 727-409-1194 - Voice http://bryanfields.net