coryb27 Posted January 23, 2016 Report Posted January 23, 2016 Due to the duplexer failing I decided over the winter months I would rebuild the Chain O' Lakes repeater in Ingleside IL. I had a spare 100W MTR2000 in the garage and decided this was going to be the heart of the new machine. Tuning it down to 50W would insure a solid 100% duty cycle and provide years of service. Due to past bad experiences with EBay duplexers I decided to purchase a new one and settled on an EMR 4 cavity pass / reject with a factory tune. Being a tinkerer that loves to build things I decided to dig out all the radio junk and see what I could come up with. The finished system will have an on board Bird 43 SWR / power meter and one of those micro mobile UHF radios for testing , monitoring and local use. To limit loss and interference I plumbed the entire system with ¼ helix superflex trimmed to critical lengths. Over the past several months I was having issues with another systme on .550 so come spring it will be moving to .725. I am still waiting on a few more items to finish this build and will keep this thread updated. http://cor3com.com/mygmrs/fr.jpg http://cor3com.com/mygmrs/emr.jpg This is the tower at my site, 150' with a DB420 on the top. http://cor3com.com/mygmrs/tower.jpg Logan5, Swords and JohnE 3 Quote
JohnE Posted January 23, 2016 Report Posted January 23, 2016 nice neat little package.duplexer plot looks great.what's the yagi for? Quote
coryb27 Posted January 23, 2016 Author Report Posted January 23, 2016 We used to have 2 repeaters at the site. The Yagi ran a Motorola R100, you could get into it 48 miles away at the house. It has since been taken down and replaced with a side arm and station master running a friends Ham repeater. Quote
JohnE Posted January 23, 2016 Report Posted January 23, 2016 We used to have 2 repeaters at the site. The Yagi ran a Motorola R100, you could get into it 48 miles away at the house. It has since been taken down and replaced with a side arm and station master running a friends Ham repeater.wow what a relic. Quote
JohnE Posted January 23, 2016 Report Posted January 23, 2016 6U Tripplite case, nice.used one for a customer wall mounted w/XBR8400 ,small celwave duplexer and 35AHr battery. little tight but it worked. Quote
gortex2 Posted January 24, 2016 Report Posted January 24, 2016 Nice looking equipment. Kudos on the 1/4" for jumpers. What hard line are you running up the tower. Just installed 150' of 1 1/4" on my repeater and amazed at the night and day vs the 1//2" it replaced. Quote
JohnE Posted January 24, 2016 Report Posted January 24, 2016 1/2" has a 1.5 dB loss and 1 1/4 " is .6, big difference at 150'~2.25 vs ~.9db loss.nice change Quote
coryb27 Posted January 24, 2016 Author Report Posted January 24, 2016 I have 7/8 on the tower, the run is 160' total, I had a 30W R100 at this site for about 5 months and it was usable 45 miles away. JohnE 1 Quote
n4gix Posted January 24, 2016 Report Posted January 24, 2016 I wish I had a nice tower for my future repeater. Alas, I'm stuck with a tripod roof mounted antenna at about 42'. It still should be good enough to cover the roughly 10 mile radius I need for now. Quote
quarterwave Posted January 24, 2016 Report Posted January 24, 2016 Can't beat that MTR for solid performance, I run one with a Zetron and a ASP fiberglass antenna (800 model I think) 22 feet long on my 50 foot tower, which is on a hill 150 feet above average terrain. It has always provided good range. Before the MTR, I had 2 mobiles running, it was good, the MTR is the real deal though. For duplexing I run 2 receive cans, and one transmit can, stuff salvaged out of an old Motorola community repeater. Works great. JohnE 1 Quote
gortex2 Posted January 25, 2016 Report Posted January 25, 2016 Came across the cable left over from another project and didn't want it to go to waste ! The MTR is a rock solid repeater. Unfortunately mine is a MTR3000 and I'm not a huge fan of it. Have a few Quantars sitting so may swap one in. Quote
coryb27 Posted January 25, 2016 Author Report Posted January 25, 2016 I finished installing the on board Bird 43 inline SWR / Power meter, getting closer! http://cor3com.com/mygmrs/side.jpg JohnE 1 Quote
coryb27 Posted January 26, 2016 Author Report Posted January 26, 2016 Well its done, now to get it tuned, tested and installed. JohnE 1 Quote
ASRM Posted January 26, 2016 Report Posted January 26, 2016 I wish I had a nice tower for my future repeater. Alas, I'm stuck with a tripod roof mounted antenna at about 42'. It still should be good enough to cover the roughly 10 mile radius I need for now.n4gix. don't feel bad, we are doing a similar setup, eave mount at 15' and a 30 foot channel master pipe with a 6dbd/9dbi Comet antenna. We get 15 miles mobile for the most part and we have lots of hills and gullys in the way. If I had that 150 foot monster I would rule the world Quote
n4gix Posted January 26, 2016 Report Posted January 26, 2016 If I had that 150 foot monster I would rule the world Well, your county maybe. That is one fine and professionally built repeater Cory is building! coryb27 1 Quote
coryb27 Posted January 27, 2016 Author Report Posted January 27, 2016 Well, your county maybe. That is one fine and professionally built repeater Cory is building! Well thanks William, I think it turned out OK. I try do build all my gear as good as I can using the best parts I have on hand of can afford. I am sure the 1/4 helix jumpers are overkill but way better then 90% shielded coax... I know its made a difference on my commercial repeaters so it can hurt the GMRS ones. Quote
JohnE Posted January 27, 2016 Report Posted January 27, 2016 1/4 " is definitely not overkill. most of the stuff I do uses 1/2" superflex, beats using 213/400 cables. Quote
coryb27 Posted January 28, 2016 Author Report Posted January 28, 2016 1/4 " is definitely not overkill. most of the stuff I do uses 1/2" superflex, beats using 213/400 cables. I used some 1/2 on the amplifier output on my commercial Mototrbo system but mostly 1/4 for jumpers etc... Pic's included. Second rack to the left of mine is the National Weather Service radio for our area. Everybody loves an equipment shelter pic! Quote
JohnE Posted January 28, 2016 Report Posted January 28, 2016 3" EIA, guess there is some broadcast stuff there. not to mention the battery rack Quote
coryb27 Posted January 28, 2016 Author Report Posted January 28, 2016 Used to be a 10KW TV transmitter at the site, its no longer operational. Quote
coryb27 Posted January 28, 2016 Author Report Posted January 28, 2016 should have hooked up to that LOL That would have been fun, and it would have a lot less loss at the tower top. (485') I am lucky to have shared use of a receive antenna at the top but only licensed for 150' on my transmit. Quote
coryb27 Posted January 31, 2016 Author Report Posted January 31, 2016 Well its programmed, tested and ready for service, maybe I can get it installed this week. Together the unit preforms better then expected, it should have some good ears! Quote
n4gix Posted February 1, 2016 Report Posted February 1, 2016 I probably still won't be able to hit it from North Hammond, IN. I can hit the Joliet repeater though full quieting. Quote
coryb27 Posted February 7, 2016 Author Report Posted February 7, 2016 Its up and running, tested range and found it to be way better then expected. Portable's worked 15+ miles and mobiles 30+ with full quieting. If your in the area use and enjoy! Corey Logan5 and JohnE 2 Quote
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