I was over today doing some more work at the site, everything is still online and operating. I swapped the LMR400 coax out for 1/2" heliax and grounded it for one of the business band repeaters today, and remounted the GPS antenna on a better mount. I pulled 9 runs of CAT-5 for the data radios and installed a UPS from home too. Granted this doesn't seam like much, but there is quite a bit that goes into putting in coax. * The heliax needs connectors on it which takes about 20 min per connector to install. * Coax needs to be grounded with a ground kit after it's installed, and this requires antioxidant compound and cleaning. Then you have to seal up the jacket of the coax. * once inside the shelter you need to install a lightning arrestor with more antioxidant * then a jumper of coax is made up and fished in the ladder racks to the repeater. Tomorrow we will get the grounding done up at the top roof and some final tweaking of the antennas completed. If all goes well I'd like to get the 440 and 900 mhz repeaters interfaced to the computer controller and off the internal controllers. This will allow us to link them to the 220 and other repeaters once the internet is hooked up. We may be adding a pre-amp to the 440 repeater to see if we can get it hearing a bit better. The 220 is working well enough to not mess with at this point. 900 seams to actually be working well as far as I can tell. We've not heard many people on 900 to test with. This is the 220/900/440 repeaters in the rack <http://gallery.keekles.org/v/Radio_stuff/Site+location/Coax/0305161637.jpg.html> This is the coax entrance in the shelter with the polyphaser <http://gallery.keekles.org/d/30663-2/0306161825b.jpg> lightning protectors installed 73's -- Bryan Fields, W9CR Florida Simulcast Group, Inc.
We accomplished much today even with the wind gusting to 50 mph on the roof. We didn't get the computer interfacing done just yet, but we did get all 5 repeaters terminated with 1/2 heliax from the lightning arrestors in the shelter. We installed 4 coax grounds bonding the coax to the "birdcage". Of most interest the group will be the improvements made to the 443.525 with the addition of a preamplifier. This is a receiver amplifier that sits post the receiver side of the duplexer and improves the sensitivity of the receiver. We measured the receiver sensitivity before adding the pre-amp and found it was -119.5 dBm for 12dB of signal/noise, which is quite good. With the pre-amp inline we measured the sensitivity as -126.5, and improvement of about 7dB. This is quite frankly amazing as the thermal noise in a 25 kHz channel is -130 dBm, so we're 4db more than the noise for a usable signal. You will see this as much improved signals on HT's and lower power/further out mobiles. We're ready once we get internet fiber in place for linking and installing the data radios. Please get on and give it a try. 73's -- Bryan Fields, W9CR Florida Simulcast Group, Inc.
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Bryan Fields