Duncarnold Posted May 26, 2007 Share Posted May 26, 2007 We have recently installed a new base unit for our Motorola radios, made by Key K. It has a really noisy fan which is causing a problem as it is next to the prompt desk, making cans horrible! Its a long shaft-like fan, so it's not a simple fan swap job! Any ideas? Anyone heard of Key K, got similar experience etc... Other than moving the unit or screening it from the DSM.Cheers. Link to comment Share on other sites More sharing options...
pritch Posted May 26, 2007 Share Posted May 26, 2007 Are you sure it's Key K, and not just Key? http://www.keyradio.com/ Link to comment Share on other sites More sharing options...
Duncarnold Posted May 26, 2007 Author Share Posted May 26, 2007 Thanks! It is just Key. Link to comment Share on other sites More sharing options...
dbuckley Posted May 26, 2007 Share Posted May 26, 2007 If its a decent base station it'll have a remote control option. Put the mic and speaker by the SM, and the electronics 'elsewhere' where the fan racket ont matter. Link to comment Share on other sites More sharing options...
Duncarnold Posted May 26, 2007 Author Share Posted May 26, 2007 Its not even half decent (budgetary restraints are cool aren't they), so no remote option. Whoopee! For now I've moved it to other side of control room. Lets see if we have complaints from the LX op in notes tonight... Link to comment Share on other sites More sharing options...
pritch Posted May 27, 2007 Share Posted May 27, 2007 Does the fan run constantly, or only when the unit gets warm? Their website says the units can run from 1-25W, so it may be worth turning the output power down if it's the latter. 25W is quite a large amount of power, especially if you only need it in and around your building. Link to comment Share on other sites More sharing options...
emsgeorge Posted May 28, 2007 Share Posted May 28, 2007 We have a KEY K450 uhf repeater / base in our venue, and it has no fan at the heatsink on the rear - runs 25 watts, and rarely gets warm. However, the power supply has a fan on the rear - which ran at full blast all the time. We replaced it with one of those computer fans, which has a little temp sensor and pcb. Stick the temp sensor onto the power supply heatsink, and voila, the fan only runs when it needs cooling. Think the whole new fan and temp kit was less than £20 at maplin. Link to comment Share on other sites More sharing options...
cedd Posted May 28, 2007 Share Posted May 28, 2007 25 Watts!!!!!! Ouch! The commercial radio systems I use at work (an international airport) for communications between vehicles on the airfield and Air Traffic Control are only 5W (fair enough, they are very expensive 5W systems, with very god quality cable and antennae, but nevertheless). 5W covers our 3 mile square site easily, including in the deepest bowels of the terminal building. Turn your power down and see what happens! Link to comment Share on other sites More sharing options...
paulears Posted May 28, 2007 Share Posted May 28, 2007 I suspect your licence would also not permit 25W output either. Internal systems are normally erp limited - however, the transmitter power is not the real issue, it's how much actually gets radiated at the antenna - and if you have very long feeders to the antenna, much, much less than 25 W will emerge at the other end! The licence usually states the EIRP, not the transmitter output power. Link to comment Share on other sites More sharing options...
cedd Posted May 28, 2007 Share Posted May 28, 2007 Indeed Paul you're correct, we are licensed for 5W at the antenna. We set all of our base stations to 5W knowing full well there will be losses, especially as we have a rather convoluted route to the aerial farm. Nevertheless a quick check with a Bird Thruline at the antenna connection is pretty close to 5. As for how much goes to air, we don't actually measure it, nevertheless it's never proven a problem with coverage. We do use very good quality (Jaybeam) antenna's. I still wonder whether 25 watts is a little high. Assuming the aerial and coax used are of slightly lesser quality than I'm used to at work, it's still an awful lot of power to put to air to propogate through what I assume is a large theatre. I'd certainly be checking my license (assuming it's a licensed system). Of course unless the fan is switched with heat, this is all irrelevant really. We have a similair issue with very noisy fans on our Tait base stations at work. Luckily we have our own plant room with a remote connection for our controllers, so no noise complaints. Link to comment Share on other sites More sharing options...
emsgeorge Posted May 29, 2007 Share Posted May 29, 2007 Thanks for evenyones help - I've just spent 2 or so hours trying to track down who supplied our radio kit, as have had an engineer in to look at the base station, as a result of people on here saying that 25w is a bit too high. He found it was set to more like 35 by the time it came out of the aerial - because of the antenna gain. Luckily the guy does lots of radios round here, and thinks nobody was on the same freq for a long distance. Now back to 5w -and no difference with reception at all. God knows how far we were transmitting our morning coffee orders. EDIT: Just found out who installed it - its been like this since day 1 of install , around 1990 !!!!!!!!!!!!!!!!!!!!!!! Link to comment Share on other sites More sharing options...
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