A few words from our club’s Technical Team …
The North Shore Radio Club is sponsoring a new DMR (Digital Mobile Radio) repeater on 441.21875 MHz from Chicago. DMR is ham radio’s newest digital voice 2-way technology and is a 2-slot (channel) TDMA worldwide standard. DMR radios are manufacturered by Motorola, Vertex Standard, Hytera, Tytera, Simoco, Kirisun, Tait, Connect Systems, soon Alinco, and a few other smaller companies. Our DMR repeater allows portable and mobile coverage across the Chicagoland area. It is affiliated with the DMR-MARC worldwide network of 500+ repeaters in 23 countries. Locally, it is connected to Schaumburg, Crystal Lake, Bolingbrook, Morris, Sugar Grove, Milwaukee, Green Bay, Crown Point, Valparaiso, and LaPorte. See the coverage maps here.
The neat aspect of DMR is that you can have 2 unique groups of people having 2 totally independent conversations on the same repeater! The repeater has 2 voice channels, remember? You can also set your Motorola radio to automatically roam between the Tri-State area repeaters without having to change the dial manually! It’s just like a cell phone, in that sense. This makes DMR a great technology for distraction free driving and safety.
Radios may be purchased via the following avenues:
Sandy’s Communications (ask for Jeff Samuels and mention the “amateur radio discount”)
Hamfests and Swaps
Here are the talk groups and frequency configurations:
AA9VI 441.21875 +5 MHz Color Code 1
Time Slot #1- Group Call 3 = North America (PTT Activated)
Time Slot #1 - Group Call 13 = Worldwide English
Time Slot #1 - Group Call 100= Tech Talk
Time Slot #1- Group Call 113 = UA 113 (PTT Activated)
Time Slot #1- Group Call 3169 = Midwest Regional
Time Slot #1- Group Call 9999 = Audio Test (PTT Activated)
Time Slot #2 - Group Call 2 = Tri-State Local
Radio programming instructions can be found here. Be sure to disable ARS and AGC on your radio! READ ALL OF THE INSTRUCTIONS BEFORE PRESSING PUSH TO TALK!
If you have any questions, contact Mike, AA9VI @ arrl.net (leave out the spaces)
Have you ever wanted to generate coverage plots of your local VHF/UHF station or a local repeater? There is a program called Radio Mobile which is a free download. Until recently, it has been difficult to set up. Now, G3TVU has made a self-extracting executable that will set up neary everything for you including an example. Give it a try. Fun stuff. http://www.g3tvu.co.uk/Radio_Mobile.htm
I hope you enjoy our new website with blogging capabilities. This allows the general membership to get real-time updates of activities. Many of us on the tech team get asked questions on the air so this is a chance for me to beat you to it!
First, the 442.725+ analog repeater is working well. The firmware upgrade a month or so ago has been successful in minimizing the audio clipping. If you hear someone clipping, they are over deviating and need to adjust the audio gain of their mic. Somewhere down the road we’ll have an announcement about further upgrades and features on that repeater. Keep your ear open. For now, paid club members are welcome to use the echolink feature on this repeater. If you are not a paid member and use these systems frequently, please consider the modest membership support so we can keep these systems going. Rent, electricity bills, broadband bills, equipment and maintenance are not free. We need your help every year.
The 440 D-star repeater had a bad coax jumper from the duplexer cans to the heliax drop from the roof. That was replaced. Dave, N3BXY, bought a preamp that was installed on the receiver. So, from what I have heard from those with the D-Star equipment, that system is doing quite well.
The audio on 147.345+ analog repeater now @ Techny has been optomized and sounds well. We currently are waiting for a replacement preamp since the old one had failed. We also will be updating our 2m repeater with a new one in the near future. The duplexer cans checked out OK and a new preamp was added to replaced the old failed one.
The 144.39 APRS and 145.61 BBS systems @ Techny are now on one antenna after I tuned up some duplexer cans. All indications are that those are working well too.
The 220 cans were just retuned and that repeater sounds better than ever before. Give it a try.
Finally, I have been busy with the Motorola club too. There are 2 new DMR MOTOTRBO repeaters up that have IP site connect to 2 seperate systems of 10-15 repeaters each. DMR is Digital Mobile Radio and you get 2 voice channels from each repeater. I’ve been hanging out there more lately, so maybe you can get yourself a DMR radio and find me on 444.79375+ (Schaumburg) or 443.35+ (Lake Zurich) both are color code 1 (like the digital PL). Here are some links to get you started on DMR if you are interested: